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SonicOS 5.9 Admin Guide

VPN

Configuring VPN Policies

VPN > Settings

The VPN > Settings page provides the SonicWall features for configuring your VPN policies. You can configure site-to-site VPN policies and GroupVPN policies from this page. The VPN > Settings page also displays a table of currently active VPN tunnels.

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VPN Overview

A Virtual Private Network (VPN) provides a secure connection between two or more computers or protected networks over the public Internet. It provides authentication to ensure that the information is going to and from the correct parties. It provides security to protect the information from viewing or tampering en route.

Prior to the invention of Internet Protocol Security (IPsec) and Secure Socket Layer (SSL), secure connections between remote computers or networks required a dedicated line or satellite link. This was both inflexible and expensive.

A VPN creates a connection with similar reliability and security by establishing a secure tunnel through the Internet. Because this tunnel is not a physical connection, it is more flexible--you can change it at any time to add more nodes, change the nodes, or remove it altogether. It is also far less costly, because it uses the existing Internet infrastructure.

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For information on configuring VPNs in SonicOS, see the following sections:

VPN Types

There are two main types of VPN in popular use today:

IPsec VPN: IPsec is a set of protocols for security at the packet processing layer of network communication. An advantage of IPsec is that security arrangements can be handled without requiring changes to individual user computers. SonicOS supports the creation and management of IPsec VPNs.

IPsec provides two choices of security service: Authentication Header (AH), which essentially allows authentication of the sender of data, and Encapsulating Security Payload (ESP), which supports both authentication of the sender and encryption of data as well. The specific information associated with each of these services is inserted into the packet in a header that follows the IP packet header.

SSL VPN: Secure Socket Layer (SSL) is a protocol for managing the security of a message transmission on the Internet, usually by HTTPS. SSL uses a program layer located between the Internet's Hypertext Transfer Protocol (HTTP) and Transport Control Protocol (TCP) layers. SSL uses the public-and-private key encryption system from RSA, which also includes the use of a digital certificate. An SSL VPN uses SSL to secure the VPN tunnel.

One advantage of SSL VPN is that SSL is built into most Web Browsers. No special VPN client software or hardware is required.

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NOTE: SonicWall makes SSL VPN devices that you can use in concert with or independently of a SonicWall network security appliance running SonicOS. For information on SonicWall SSL VPN appliances, see the SonicWall Website: http://www.SonicWall.com/us/products.html.

VPN Security

IPsec VPN traffic is secured in two stages:

Authentication: The first phase establishes the authenticity of the sender and receiver of the traffic using an exchange of the public key portion of a public-private key pair. This phase must be successful before the VPN tunnel can be established.
Encryption: The traffic in the VPN tunnel is encrypted, using an encryption algorithm such as AES or 3DES.

Unless you use a manual key (which must be typed identically into each node in the VPN) The exchange of information to authenticate the members of the VPN and encrypt/decrypt the data uses the Internet Key Exchange (IKE) protocol for exchanging authentication information (keys) and establishing the VPN tunnel. SonicOS supports two versions of IKE:

IKE version 1

IKE version 1 uses a two phase process to secure the VPN tunnel.

IKE Phase 1 is the authentication phase. The nodes or gateways on either end of the tunnel authenticate with each other, exchange encryption/decryption keys, and establish the secure tunnel. See IKE Phase 1.
IKE Phase 2 is the negotiation phase. Once authenticated, the two nodes or gateways negotiate the methods of encryption and data verification (using a hash function) to be used on the data passed through the VPN and negotiate the number of secure associations (SAs) in the tunnel and their lifetime before requiring renegotiation of the encryption/decryption keys. See IKE Phase 2.
IKE Phase 1

In IKE v1, there are two modes of exchanging authentication information: Main Mode and Aggressive Mode.

Main Mode: The node or gateway initiating the VPN queries the node or gateway on the receiving end, and they exchange authentication methods, public keys, and identity information. This usually requires six messages back and forth. The order of authentication messages in Main Mode is:
a
The initiator sends a list of cryptographic algorithms the initiator supports.
b
The responder replies with a list of supported cryptographic algorithms.
c
The initiator send a public key (part of a Diffie-Hellman public/private key pair) for the first mutually supported cryptographic algorithm.
d
The responder replies with the public key for the same cryptographic algorithm.
e
The initiator sends identity information (usually a certificate).
f
The responder replies with identity information.
Aggressive Mode: To reduce the number of messages exchanged during authentication by half, the negotiation of which cryptographic algorithm to use is eliminated. The initiator proposes one algorithm and the responder replies if it supports that algorithm:
a
The initiator proposes a cryptographic algorithm to use and sends its public key.
b
The responder replies with a public key and identity proof.
c
The initiator sends an identification proof. After authenticating, the VPN tunnel is established with two SAs, one from each node to the other.
IKE Phase 2

In IKE phase 2, the two parties negotiate the type of security to use, which encryption methods to use for the traffic through the tunnel (if needed), and negotiate the lifetime of the tunnel before re-keying is needed.

The two types of security for individual packets are:

Encryption Secured Payload (ESP), in which the data portion of each packet is encrypted using a protocol negotiated between the parties.
Authentication Header (AH), in which the header of each packet contains authentication information to ensure the information is authenticated and has not been tampered with. No encryption is used for the data with AH.

SonicOS supports the following encryption methods for Traffic through the VPN.

DES
3DES
AES-128
AES-192
AES-256

You can find more information about IKE v1 in the three specifications that define initially define IKE, RFC 2407, RFC 2408, and RFC 2409, available on the Web at:

IKEv2

IKE version 2 is a new protocol for negotiating and establishing SAs. IKEv2 features improved security, a simplified architecture, and enhanced support for remote users. In addition, IKEv2 supports IP address allocation and EAP to enable different authentication methods and remote access scenarios. Using IKEv2 greatly reduces the number of message exchanges needed to establish an SA over IKE v1 Main Mode, while being more secure and flexible than IKE v1 Aggressive Mode. This reduces the delays during re-keying. As VPNS grow to include more and more tunnels between multiple nodes or gateways, IKEv2 reduces the number of SAs required per tunnel, thus reducing required bandwidth and housekeeping overhead.

IKEv2 is not compatible with IKE v1. If using IKEv2, all nodes in the VPN must use IKEv2 to establish the tunnels.

SAs in IKEv2 are called Child SAs and can be created, modified, and deleted independently at any time during the life of the VPN tunnel.

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Initialization and Authentication in IKEv2

IKEv2 initializes a VPN tunnel with a pair of message exchanges (two message/response pairs).

Initialize communication: The first pair of messages (IKE_SA_INIT) negotiate cryptographic algorithms, exchange nonces (random values generated and sent to guard against repeated messages), and perform a public key exchange.
Initiator sends a list of supported cryptographic algorithms, public keys, and a nonce.
Responder sends the selected cryptographic algorithm, the public key, a nonce, and an authentication request.
Authenticate: The second pair of messages (IKE_AUTH) authenticate the previous messages, exchange identities and certificates, and establish the first CHILD_SA. Parts of these messages are encrypted and integrity protected with keys established through the IKE_SA_INIT exchange, so the identities are hidden from eavesdroppers and all fields in all the messages are authenticated.
Initiator sends identity proof, such as a shared secret or a certificate, and a request to establish a child SA.
Responder sends the matching identity proof and completes negotiation of a child SA.
Negotiating SAs in IKEv2

This exchange consists of a single request/response pair, and was referred to as a phase 2 exchange in IKE v1. It may be initiated by either end of the SA after the initial exchanges are completed.

All messages following the initial exchange are cryptographically protected using the cryptographic algorithms and keys negotiated in the first two messages of the IKE exchange.

Either endpoint may initiate a CREATE_CHILD_SA exchange, so in this section the term “initiator” refers to the endpoint initiating this exchange.

1
Initiator sends a child SA offer and, if the data is to be encrypted, the encryption method and the public key.
2
Responder sends the accepted child SA offer and, if encryption information was included, a public key.
Configuration Payload

The IKEv2 configuration payload (CP) allows the VPN server to dynamically assign IP addresses to remote clients. The client and server exchange information, similar to a DHCP negotiation as if the client was directly connected to a LAN.

When IKEv2 is selected as the exchange method for the IKE phase 1 proposal, the administrator can choose to assign the client an IP address from the IKEv2 IP address pool.

IKEv2 configuration payloads are intended for relatively small-scale deployments.

Windows 7 IKEv2 Client

When used with SonicWall appliances, the Windows 7 IKEv2 client must use third party certificates as the authentication method. The certificates installed on the remote access server should have the following values:

Common Name (CN): This field must contain the fully qualified DNS name or IP address of the remote access server. If the server is located behind a network address translating (NAT) router, then the certificate must contain the fully qualified DNS name or IP address of the external connection of the NAT router (the address that the client computer sees as the address of the server).
EKU: This field must includes Server Authentication. If there is more than one server authentication certificate, additionally include the IP security IKE intermediate EKU. Only one certificate should have both EKU options, otherwise IPsec cannot determine which certificate to use, and might not pick the certificate you intended. For more information, see:

http://technet.microsoft.com/en-us/library/dd941612(WS.10).aspx.

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NOTE: You can find more information about IKEv2 in the specification, RFC 4306, available on the Web at: http://www.ietf.org/rfc/rfc4306.txt.

Configuring VPNs in SonicOS

For an overview of VPNs in SonicOS, see VPN > Settings.

SonicWall VPN, based on the industry-standard IPsec VPN implementation, provides a easy-to-setup, secure solution for connecting mobile users, telecommuters, remote offices and partners via the Internet. Mobile users, telecommuters, and other remote users with broadband (DSL or cable) or dialup Internet access can securely and easily access your network resources with the SonicWall Global VPN Client and SonicWall GroupVPN on your SonicWall. Remote office networks can securely connect to your network using site-to-site VPN connections that enable network-to- network VPN connections.

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NOTE: For more information on the SonicWall Global VPN Client, see the SonicWall Global VPN Client Administrator’s Guide.

SonicWall’s GroupVPN provides automatic VPN policy provisioning for SonicWall Global VPN Clients. The GroupVPN feature on the SonicWall security appliance and the SonicWall Global VPN Client dramatically streamline VPN deployment and management. Using SonicWall’s Client Policy Provisioning technology, you define the VPN policies for Global VPN Client users. This policy information automatically downloads from the SonicWall security appliance (VPN Gateway) to Global VPN Clients, saving remote users the burden of provisioning VPN connections.

You can easily and quickly create a site-to-site VPN policy or a GroupVPN policy using the VPN Policy Wizard. You can also configure GroupVPN or site-to-site VPN tunnels using the Management Interface. You can define up to four GroupVPN policies, one for each zone. You can also create multiple site-to-site VPN. The maximum number of policies you can add depends on your SonicWall model.

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NOTE: Remote users must be explicitly granted access to network resources on the Users > Local Users or Users > Local Groups pages. When configuring local users or local groups, the VPN Access tab affects the ability of remote clients using GVC connecting to GroupVPN; it also affects remote users using NetExtender, and SSL VPN Virtual Office bookmarks to access network resources. To allow GVC, NetExtender, or Virtual Office users to access a network resource, the network address objects or groups must be added to the “allow” list on the VPN Access tab.
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VPN Policy Wizard

The VPN Policy Wizard walks you step-by-step through the configuration of GroupVPN or site-to-site VPN policies on the SonicWall security appliance. After completing the configuration, the wizard creates the necessary VPN settings for the selected policy. You can use the SonicOS management interface for optional advanced configuration options.

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NOTE: For step-by-step instructions on using the VPN Policy Wizard, see Wizards > VPN Wizard.

VPN Global Settings

The Global VPN Settings section of the VPN > Settings page displays the following information:

Enable VPN must be selected to allow VPN policies through the SonicWall security policies.
Unique Firewall Identifier - the default value is the serial number of the SonicWall. You can change the Identifier, and use it for configuring VPN tunnels.

VPN Policies

All existing VPN policies are displayed in the VPN Policies table. Each entry displays the following information:

Name: Displays the default name or user-defined VPN policy name.
Gateway: Displays the IP address of the remote SonicWall. If 0.0.0.0 is used, no Gateway is displayed.
Destinations: Displays the IP addresses of the destination networks.
Crypto Suite: Displays the type of encryption used for the VPN policy.
Enable: Selecting the check box enables the VPN Policy. Clearing the check box disables it.
Configure: Clicking the:
Edit icon allows you to edit the VPN policy.
Delete icon allows you to delete the VPN policy. The predefined GroupVPN policies cannot be deleted, so the Delete icons are dimmed. also have an
Export icon for GroupVPN policies allows you to export the VPN policy configuration as a file for local installation by SonicWall Global VPN Clients. The file can be saved in either format:
spd – Required for VPN Clients 8.x and earlier; is not encrypted.
rcf – Required for Global VPN Clients; may be password encrypted.

The number of VPN policies defined, policies enabled, and the maximum number of Policies allowed is displayed below the table. You can define up to 4 GroupVPN policies, one for each zone. These GroupVPN policies are listed by default in the VPN Policies table as WAN GroupVPN, LAN GroupVPN, DMZ GroupVPN, and WLAN GroupVPN. Clicking on the Edit icon in the Configure column for the GroupVPN displays the VPN Policy dialog for configuring the GroupVPN policy.

Below the VPN Policies table are the following buttons:

Add - Accesses the VPN Policy dialog to configure site-to-site VPN policies.
Delete - Deletes the selected (checked box before the VPN policy name in the Name column. You cannot delete the GroupVPN policies.
Delete All - Deletes all VPN policies in the VPN Policies table except the default GroupVPN policies.
Navigating and Sorting the VPN Policies Entries

The VPN Policies table provides easy pagination for viewing a large number of VPN policies. You can navigate a large number of VPN policies listed in the VPN Policies table by using the navigation control bar located at the top right of the VPN Policies table. Navigation control bar includes four buttons. The far left button displays the first page of the table. The far right button displays the last page. The inside left and right arrow buttons moved the previous or next page respectively.

You can enter the policy number (the number listed before the policy name in the # Name column) in the Items field to move to a specific VPN policy. The default table configuration displays 50 entries per page. You can change this default number of entries for tables on the System > Administration page.

You can sort the entries in the table by clicking on the column header. The entries are sorted by ascending or descending order. The arrow to the right of the column entry indicates the sorting status. A down arrow means ascending order. An up arrow indicates a descending order.

Currently Active VPN Tunnels

A list of currently active VPN tunnels is displayed in this section. The table lists the name of the VPN Policy, the local LAN IP addresses, and the remote destination network IP addresses as well as the peer gateway IP address.

Click the Renegotiate button to force the VPN Client to renegotiate the VPN tunnel.

Viewing VPN Tunnel Statistics

In the Currently Active VPN Tunnels table, click on the Statistics icon in the row for a tunnel to view the statistics on that tunnel:

Create Time: The date and time the tunnel came into existence.
Tunnel valid until: The time when the tunnel expires and is force to renegotiate.
Packets In: The number of packets received from this tunnel.
Packets Out: The number of packets sent out from this tunnel.
Bytes In: The number of bytes received from this tunnel.
Bytes Out: The number of bytes sent out from this tunnel.
Fragmented Packets In: The number of fragmented packets received from this tunnel.
Fragmented Packets Out: The number of fragmented packets sent out from this tunnel.

For detailed information on configuring VPNs in SonicOS, see:

Configuring VPNs for IPv6

For complete information on the SonicOS implementation of IPv6, see the About IPv6.

IPsec VPNs can be configured for IPv6 in a similar manner to IPv4 VPNs after selecting the IPv6 option in the View IP Version radio button at the top left of the VPN > Settings page.

There are certain VPN features that are currently not supported for IPv6, including:

IKEv2 is supported, while IKEv1 is currently not supported
GroupVPN is not supported
DHCP Over VPN is not supported.

When configuring an IPv6 VPN policy, on the General tab the gateways must be configured using IPv6 addresses. FQDN is not supported. When configuring IKE authentication, IPV6 addresses can be used for the local and peer IKE IDs.

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NOTE: DHCP Over VPN and L2TP Server are not supported for IPv6.

On the Network tab of the VPN policy, IPV6 address objects (or address groups that contain only IPv6 address objects) must be selected for the Local Network and Remote Network.

DHCP Over VPN is not supported, thus the DHCP options for protected network are not available.

The Any address option for Local Networks and the Tunnel All option for Remote Networks are removed. Select an all zero IPv6 Network address object could be selected for the same functionality and behavior.

On the Proposals tab, the configuration is identical for IPv6 and IPv4, except for the fact that IPv6 only support IKEv2 mode.

On the Advanced tab, only Enable Keep Alive and the IKEv2 Settings can be configured for IPv6 VPN policies.

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NOTE: Because an interface may have multiple IPv6 address, sometimes the local address of the tunnel may vary periodically. If the user needs a consistent IP address, configure the VPN policy to be bound to an interface instead of Zone, and specify the address manually. The address must be one of IPv6 addresses for that interface.

Configuring GroupVPN Policies

SonicWall GroupVPN facilitates the set up and deployment of multiple SonicWall Global VPN Clients by the SonicWall security appliance administrator. GroupVPN is only available for SonicWall Global VPN Clients, and it is recommended you use XAUTH/RADIUS or third party certificates in conjunction with the Group VPN for added security.

For more information on the SonicWall Global VPN Client, see the SonicWall Global VPN Client Administrator’s Guide.

The default GroupVPN configuration allows you to support SonicWall Global VPN Clients without any further editing of the VPN policy, except to check the Enable box for GroupVPN in the VPN Policies table.

SonicWall supports four GroupVPN policies. You can create GroupVPN policies for the DMZ, LAN, WAN, and WLAN zones. These GroupVPN policies are listed in the VPN policies tables as WAN Group VPN, LAN GroupVPN, DMZ GroupVPN, and WLAN GroupVPN. For these GroupVPN policies, you can choose from IKE using Preshared Secret or IKE using 3rd Party Certificates for your IPsec Keying Mode.

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TIP: You can easily create GroupVPN policies using the VPN Policy Wizard. For complete step-by-step instructions on using the VPN Policy Wizard, see Wizards > VPN Wizard.
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NOTE: See the GroupVPN Setup in SonicOS technote on the SonicWall documentation Web site http://www.SonicWall.com for more GroupVPN configuration information.

SonicOS supports the creation and management of IPsec VPNs.

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Configuring GroupVPN with IKE using Preshared Secret on the WAN Zone

To configure the WAN GroupVPN:
1
Navigate to VPN > Settings.
2
Click the edit icon for the WAN GroupVPN entry. The VPN Policy dialog displays.

3
In the General tab, IKE using Preshared Secret is the default setting for Authentication Method. A Shared Secret is generated automatically by the SonicOS 5.9 Administration Guide security appliance in the Shared Secret field, or you can generate your own shared secret. Shared Secrets must be minimum of four characters.
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NOTE: You cannot change the name of any GroupVPN policy.
4
Click the Proposals tab to continue the configuration process.

5
In the IKE (Phase 1) Proposal section, use the following settings:
Select the DH Group from the DH Group drop-down menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Select 3DES, AES-128, or AES-256 from the Encryption drop-down menu.
Select the desired authentication method from the Authentication drop-down menu.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
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In the IPsec (Phase 2) Proposal section, select the following settings:
Select the desired protocol from the Protocol drop-down menu.
Select 3DES, AES-128, or AES-256 from the Encryption drop-down menu.
Select the desired authentication method from the Authentication drop-down menu.
Select Enable Perfect Forward Secrecy if you want an additional Diffie-Hellman key exchange as an added layer of security. The DH Group drop-down menu displays.
Select Group 2 from the DH Group drop-down menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
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Click the Advanced tab.

8
Select any of the following optional settings you want to apply to your GroupVPN policy:
Disable IPsec Anti-Replay - Disables Anti-Replay, which is a form of partial sequence integrity that detects arrival of duplicate IP datagrams (within a constrained window).
Enable Windows Networking (NetBIOS) broadcast - Allows access to remote network resources by browsing the Windows® Network Neighborhood.
Enable Multicast - Enables IP multicasting traffic, such as streaming audio (including VoIP) and video applications, to pass through the VPN tunnel.
Accept Multiple Proposals for Clients - Allows L2TP, iOS, and Windows clients to connect to the SonicOS L2TP server at the same time.
Enable IKE Mode Configuration - Allows SonicOS to assign internal IP address, DNS Server, or WINS Server to third-party clients such as iOS devices or Avaya IP phones.
Management via this SA: - If using the VPN policy to manage the SonicWall security appliance, select the management method, either HTTP, HTTPS, SSH, or SNMP.
Default Gateway - Allows you to specify the IP address of the default network route for incoming IPsec packets for this VPN policy.

Incoming packets are decoded by the SonicWall and compared to static routes configured in the SonicWall security appliance. As packets can have any IP address destination, it is impossible to configure enough static routes to handle the traffic. For packets received via an IPsec tunnel, the SonicWall looks up a route. If no route is found, the security appliance checks for a Default Gateway. If a Default Gateway is detected, the packet is routed through the gateway. Otherwise, the packet is dropped.

Require Authentication of VPN Clients via XAUTH - Requires that all inbound traffic on this VPN tunnel is from an authenticated user. Unauthenticated traffic is not allowed on the VPN tunnel. The Trusted users group is selected by default. You can select another user group or Everyone from User Group for XAUTH users or create a new group.
Allow Unauthenticated VPN Client Access - Allows you to enable unauthenticated VPN client access. If you uncheck Require Authentication of VPN Clients via XAUTH, the Allow Unauthenticated VPN Client Access menu is activated. Select an Address Object or Address Group from the drop-down menu of predefined options, or select Create new address object or Create new address group to create a new one.
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Click the Client tab, select any of the following settings you want to apply to your GroupVPN policy.

Cache XAUTH User Name and Password on Client - Allows the Global VPN Client to cache the user name and password.
Never - Global VPN Client is not allowed to cache the username and password. The user will be prompted for a username and password when the connection is enabled, and also every time there is an IKE Phase 1 rekey.
Single Session - Global VPN Client user prompted for username and password each time the connection is enabled and will be valid until the connection is disabled. The username and password is used through IKE Phase 1 rekey.
Always - Global VPN Client user prompted for username and password only once when connection is enabled. When prompted, the user will be given the option of caching the username and password.
Virtual Adapter Settings - The use of the Virtual Adapter by the Global VPN Client (GVC) is dependent upon a DHCP server, either the internal SonicOS or a specified external DHCP server, to allocate addresses to the Virtual Adapter. In instances where predictable addressing was a requirement, it is necessary to obtain the MAC address of the Virtual Adapter and to create a DHCP lease reservation. To reduce the administrative burden of providing predictable Virtual Adapter addressing, you can configure the GroupVPN to accept static addressing of the Virtual Adapter's IP configuration. This feature requires the use of GVC version 3.0 or later.
None - A Virtual Adapter will not be used by this GroupVPN connection.
DHCP Lease - The Virtual Adapter will obtain its IP configuration from the DHCP Server only, as configured in the VPN > DHCP over VPN page.
DHCP Lease or Manual Configuration - When the GVC connects to the SonicWall, the policy from the SonicWall instructs the GVC to use a Virtual Adapter, but the DHCP messages are suppressed if the Virtual Adapter has been manually configured. The configured value is recorded by the SonicWall so that it can proxy ARP for the manually assigned IP address. By design, there are currently no limitations on IP address assignments for the Virtual Adapter. Only duplicate static addresses are not permitted.
Allow Connections to - Client network traffic matching destination networks of each gateway is sent through the VPN tunnel of that specific gateway.
This Gateway Only - Allows a single connection to be enabled at a time. Traffic that matches the destination networks as specified in the policy of the gateway is sent through the VPN tunnel. If this option is selected along with Set Default Route as this Gateway, then the Internet traffic is also sent through the VPN tunnel. If this option is selected without selecting Set Default Route as this Gateway, then the Internet traffic is blocked.
All Secured Gateways - Allows one or more connections to be enabled at the same time. Traffic matching the destination networks of each gateway is sent through the VPN tunnel of that specific gateway. If this option is selected along with Set Default Route as this Gateway, then Internet traffic is also sent through the VPN tunnel. If this option is selected without Set Default Route as this Gateway, then the Internet traffic is blocked. Only one of the multiple gateways can have Set Default Route as this Gateway enabled.
Split Tunnels - Allows the VPN user to have both local Internet connectivity and VPN connectivity.
Set Default Route as this Gateway - Enable this check box if all remote VPN connections access the Internet through this VPN tunnel. You can only configure one VPN policy to use this setting.
Use Default Key for Simple Client Provisioning - uses Aggressive mode for the initial exchange with the gateway and VPN clients uses a default Preshared Key for authentication.
10
Click OK.

Configuring GroupVPN with IKE using 3rd Party Certificates

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CAUTION: Before configuring GroupVPN with IKE using 3rd Party Certificates, your certificates must be installed on the SonicWall.
To configure GroupVPN with IKE using 3rd Party Certificates:
1
In the VPN > Settings page click the edit icon under Configure. The VPN Policy dialog displays.

2
In the Security Policy section, select IKE using 3rd Party Certificates from the Authentication Method menu. The VPN policy name is GroupVPN by default and cannot be changed.
3
Select a certificate for the SonicWall from the Gateway Certificate menu.
4
Select one of the following Peer ID types from the Peer ID Type menu:
E-Mail ID and Domain Name - The Email ID and Domain Name types are based on the certificate's Subject Alternative Name field, which is not contained in all certificates by default. If the certificate does not contain a Subject Alternative Name field, this filter will not work. The E-Mail ID and Domain Name filters can contain a string or partial string identifying the acceptable range required. The strings entered are not case sensitive and can contain the wild card characters * (for more than 1 character) and ? (for a single character). For example, the string *@SonicWall.com when E-Mail ID is selected, would allow anyone with an email address that ended in SonicWall.com to have access; the string *sv.us.SonicWall.com when Domain Name is selected, would allow anyone with a domain name that ended in sv.us.SonicWall.com to have access.
Distinguished Name - based on the certificates Subject Distinguished Name field, which is contained in all certificates by default. The format of any Subject Distinguished Name is determined by the issuing Certificate Authority. Common fields are Country (C=), Organization (O=), Organizational Unit (OU=), Common Name (CN=), Locality (L=), and vary with the issuing Certificate Authority. The actual Subject Distinguished Name field in an X.509 Certificate is a binary object that must be converted to a string for matching purposes. The fields are separated by the forward slash character (/), for example: /C=US/O=SonicWall, Inc./OU=TechPubs/CN=Joe Pub

Up to three organizational units can be specified. The usage is c=*;o=*;ou=*;ou=*;ou=*;cn=*. The final entry does not need to contain a semi-colon. You must enter at least one entry, that is, c=us.

5
Enter the Peer ID filter in the Peer ID Filter field.
6
Check Allow Only Peer Certificates Signed by Gateway Issuer to specify that peer certificates must be signed by the issuer specified in the Gateway Certificate menu.
7
Click on the Proposals tab.
8
In the IKE (Phase 1) Proposal section, select the following settings:
Select the DH Group from the DH Group menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Select 3DES, AES-128, or AES-256 from the Encryption menu.
Select the desired authentication method from the Authentication menu.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
9
In the IPsec (Phase 2) Proposal section, select the following settings:
Select the desired protocol from the Protocol menu.
Select 3DES, AES-128, or AES-256 from the Encryption menu.
Select the desired authentication method from the Authentication menu.
Select Enable Perfect Forward Secrecy if you want an additional Diffie-Hellman key exchange as an added layer of security. Select Group 2 from the DH Group menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
10
Click on the Advanced tab and select any of the following optional settings that you want to apply to your GroupVPN Policy:
Enable Windows Networking (NetBIOS) broadcast - Allows access to remote network resources by browsing the Windows Network Neighborhood.
Enable Multicast - Enables IP multicasting traffic, such as streaming audio (including VoIP) and video applications, to pass through the VPN tunnel.
Permit Acceleration - Enables redirection of traffic matching this policy to the WAN Acceleration (WXA) appliance.
Management via this SA - If using the VPN policy to manage the SonicWall security appliance, select the management method, either HTTP or HTTPS.
Default Gateway - Used at a central site in conjunction with a remote site using the Route all Internet traffic through this SA check box. Default LAN Gateway allows the network administrator to specify the IP address of the default LAN route for incoming IPsec packets for this SA. Incoming packets are decoded by the SonicWall and compared to static routes configured in the SonicWall. Since packets can have any IP address destination, it is impossible to configure enough static routes to handle the traffic. For packets received via an IPsec tunnel, the SonicWall looks up a route for the LAN. If no route is found, the SonicWall checks for a Default LAN Gateway. If a Default LAN Gateway is detected, the packet is routed through the gateway. Otherwise, the packet is dropped.
Enable OCSP Checking and OCSP Responder URL - Enables use of Online Certificate Status Protocol (OCSP) to check VPN certificate status and specifies the URL where to check certificate status. See the Using OCSP with SonicWall Security Appliances.
Require Authentication of VPN Clients via XAUTH - Requires that all inbound traffic on this VPN policy is from an authenticated user. Unauthenticated traffic is not allowed on the VPN tunnel.
User group for XAUTH users - Allows you to select a defined user group for authentication.
All Unauthenticated VPN Client Access - Allows you to specify network segments for unauthenticated Global VPN Client access.
11
Click on the Client tab and select any of the following boxes that you want to apply to Global VPN Client provisioning:
Cache XAUTH User Name and Password - Allows the Global VPN Client to cache the user name and password. Select from:
Never - Global VPN Client is not allowed to cache username and password. The user will be prompted for a username and password when the connection is enabled and also every time there is an IKE phase 1 rekey.
Single Session - The user will be prompted for username and password each time the connection is enabled and will be valid until the connection is disabled. This username and password is used through IKE phase 1 rekey.
Always - The user will be prompted for username and password only once when connection is enabled. When prompted, the user will be given the option of caching the username and password.
Virtual Adapter Settings - The use of the Virtual Adapter by the Global VPN Client (GVC) is dependent upon a DHCP server, either the internal SonicOS or a specified external DHCP server, to allocate addresses to the Virtual Adapter. In instances where predictable addressing was a requirement, it is necessary to obtain the MAC address of the Virtual Adapter, and to create a DHCP lease reservation. To reduce the administrative burden of providing predictable Virtual Adapter addressing, you can configure the GroupVPN to accept static addressing of the Virtual Adapter's IP configuration. This feature requires the use of GVC version 3.0 or later.
None - A Virtual Adapter will not be used by this GroupVPN connection.
DHCP Lease - The Virtual Adapter will obtain its IP configuration from the DHCP Server only, as configure in the VPN > DHCP over VPN page.
DHCP Lease or Manual Configuration - When the GVC connects to the SonicWall, the policy from the SonicWall instructs the GVC to use a Virtual Adapter, but the DHCP messages are suppressed if the Virtual Adapter has been manually configured. The configured value is recorded by the SonicWall so that it can proxy ARP for the manually assigned IP address. By design, there are currently no limitations on IP address assignments for the Virtual Adapter. Only duplicate static addresses are not permitted.
Allow Connections to - Client network traffic matching destination networks of each gateway is sent through the VPN tunnel of that specific gateway.
This Gateway Only - Allows a single connection to be enabled at a time. Traffic that matches the destination networks as specified in the policy of the gateway is sent through the VPN tunnel. If this option is selected along with Set Default Route as this Gateway, then the Internet traffic is also sent through the VPN tunnel. If this option is selected without selecting Set Default Route as this Gateway, then the Internet traffic is blocked.
All Secured Gateways - Allows one or more connections to be enabled at the same time. Traffic matching the destination networks of each gateway is sent through the VPN tunnel of that specific gateway. If this option is selected along with Set Default Route as this Gateway, then Internet traffic is also sent through the VPN tunnel. If this option is selected without Set Default Route as this Gateway, then the Internet traffic is blocked. Only one of the multiple gateways can have Set Default Route as this Gateway enabled.
Split Tunnels - Allows the VPN user to have both local Internet connectivity and VPN connectivity.
Set Default Route as this Gateway - Enable this check box if all remote VPN connections access the Internet through this SA. You can only configure one SA to use this setting.
Use Default Key for Simple Client Provisioning - Uses Aggressive mode for the initial exchange with the gateway and VPN clients uses a default Preshared Key for authentication.
12
Click OK.

Exporting a VPN Client Policy

* 
CAUTION: The GroupVPN SA must be enabled on the SonicWall to export a configuration file.

If you want to export the Global VPN Client configuration settings to a file for users to import into their Global VPN Clients, follow these instructions:

1
Click the Export icon in the Configure column for the GroupVPN entry in the VPN Policies table. The Export VPN Client Policy window appears.

2
rcf format is required for SonicWall Global VPN Clients is selected by default. Files saved in the rcf format can be password encrypted. The SonicWall provides a default file name for the configuration file, which you can change.
3
Click Yes. The VPN Policy Export window appears.
4
Type a password in the Password field and reenter it in the Confirm Password field, if you want to encrypt the exported file. If you choose not to enter a password, the exported file is not encrypted.
5
Click Submit. If you did not enter a password, a message appears confirming your choice.
6
Click OK. You can change the configuration file before saving.
7
Save the file.
8
Click Close.

The file can be saved to a floppy disk or sent electronically to remote users to configure their Global VPN Clients.

Site-to-Site VPN Configurations

When designing VPN connections, be sure to document all pertinent IP addressing information and create a network diagram to use as a reference. A sample planning sheet is provided on the next page. The SonicWall must have a routable WAN IP address whether it is dynamic or static. In a VPN network with dynamic and static IP addresses, the VPN gateway with the dynamic address must initiate the VPN connection.

Site-to-Site VPN configurations can include the following options:

Branch Office (Gateway to Gateway) - A SonicWall is configured to connect to another SonicWall via a VPN tunnel. Or, a SonicWall is configured to connect via IPsec to another manufacturer’s firewall.
Hub and Spoke Design - All SonicWall VPN gateways are configured to connect to a central SonicWall (hub), such as a corporate SonicWall. The hub must have a static IP address, but the spokes can have dynamic IP addresses. If the spokes are dynamic, the hub must be a SonicWall.
Mesh Design - All sites connect to all other sites. All sites must have static IP addresses.

Creating Site-to-Site VPN Policies

* 
TIP: You can easily create site-to-site VPN policies using the VPN Policy Wizard. For complete step-by-step instructions on using the VPN Policy Wizard, see Wizards > VPN Wizard.

You can create or modify existing VPN policies using the VPN Policy window. Clicking the Add button under the VPN Policies table displays the VPN Policy window for configuring the following IPsec Keying mode VPN policies:

This section also contains information on configuring a static route to act as a failover in case the VPN tunnel goes down. See Configuring VPN Failover to a Static Route for more information.

* 
TIP: Use the VPN Planning Sheet for Site-to-Site VPN Policies to record your settings. These settings are necessary to configure the remote SonicWall and create a successful VPN connection.

Configuring a VPN Policy with IKE using Preshared Secret

To configure a VPN Policy using Internet Key Exchange (IKE):
1
Go to the VPN > Settings page.
2
Click the Add button. The VPN Policy dialog appears.

3
Under the General tab, from the Policy Type menu, select Site to Site.
4
Select IKE using Preshared Secret from the Authentication Method menu.
5
Enter a name for the policy in the Name field.
6
Enter the host name or IP address of the remote connection in the IPsec Primary Gateway Name or Address field.
7
If the Remote VPN device supports more than one endpoint, you may optionally enter a second host name or IP address of the remote connection in the IPsec Secondary Gateway Name or Address field.
8
Enter a Shared Secret password to be used to setup the Security Association in the Shared Secret and Confirm Shared Secret fields. The Shared Secret must be at least 4 characters long, and should comprise both numbers and letters.
9
Optionally, specify a Local IKE ID (optional) and Peer IKE ID (optional) for this Policy. By default, the IP Address (ID_IPv4_ADDR) is used for Main Mode negotiations, and the SonicWall Identifier (ID_USER_FQDN) is used for Aggressive Mode.
10
Click the Network tab.

11
Under Local Networks, select one of these:
If a specific local network can access the VPN tunnel, select a local network from the Choose local network from list drop-down menu. This is the default.
If traffic can originate from any local network, select Any Address. Use this option if a peer has Use this VPN tunnel as default route for all Internet traffic selected. Auto added rules will be created between Trusted Zones and this VPN Zone.
* 
NOTE: DHCP over VPN is not supported with IKEv2.
12
Under Remote Networks, select one of these;
If traffic from any local user cannot leave the SonicWall security appliance unless it is encrypted Use this VPN Tunnel as default route for all Internet traffic . You can only configure one SA to use this setting.
Select an address object or group from the Choose Destination network from list drop-down menu. You can create a new address object or address object group for the destination network. This is the default.
If IKEv2 Mode is selected for the Exchange method on the Proposals tab, a third option is available: the use IKEv2 IP Pool drop-down menu to assign remote clients with an IP address from the selected IP address pool. Select this option to support IKEv2 Config Payload. You can create a new address object for the IKEv2 IP address pool.
13
Click the Proposals tab.

14
in the IKE (Phase 1) Proposal section, from the Exchange drop-down menu, select one of these:
Main Mode
Aggressive Mode – Generally used when WAN addressing is dynamically assigned.
IKEv2 Mode– Causes all the negotiation to happen via IKEv2 protocols rather than using IKE Phase 1 and Phase 2. If you use IKEv2, both ends of the VPN tunnel must use IKEv2 Mode.
15
For the rest of the options in the IKE (Phase 1) Proposal section, the default values are acceptable for most VPN configurations:
DH Group – Default is Group 5. You can also choose Group 1, Group 2, or Group 14.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Encryption – Default is 3DES. You can also choose AES-128, AES-192, or AES-256 from the Authentication menu instead of 3DES for enhanced authentication security.
Authentication – Default is SHA1. You can also choose SHA256, SHA384, or SHA512 for enhanced authentication security.
Life Time – Default is 28800.
* 
NOTE: Be sure the IKE (Phase 1) Proposal values on the opposite side of the tunnel are configured to match.
16
Under IPsec (Phase 2) Proposal, the default values for Protocol, Encryption, Authentication, Enable Perfect Forward Secrecy, DH Group, and Lifetime are acceptable for most VPN SA configurations. Be sure the Phase 2 values on the opposite side of the tunnel are configured to match.
17
Click the Advanced tab. The options displayed on the Advanced tab depend on the mode selected for Exchange on the Proposals tab. Most Advanced Settings options, however, appear on for all modes. The IKEv2 Settings options appear only if IKEv2 Mode is selected for Exchange.

Advanced Settings section
18
Select Enable Keep Alive to use heartbeat messages between peers on this VPN tunnel. If one end of the tunnel fails, using KeepAlive will allow for the automatic renegotiation of the tunnel once both sides become available again without having to wait for the proposed Life Time to expire.
* 
NOTE: The KeepAlive option will be disabled when the VPN policy is configured as Central Gateway for DHCP over VPN or with a Primary Gateway Name or Address of 0.0.0.0.
19
The Suppress automatic Access Rules creation for VPN Policy setting is not enabled by default to allow the VPN traffic to traverse the appropriate zones. Select Suppress automatic Access Rules creation for VPN Policy to turn off the automatic access rules created between the LAN and VPN zones for this VPN policy.
20
IPsec Anti-Replay is a form of partial sequence integrity that detects arrival of duplicate IP datagrams (within a constrained window). To disable this feature, select Disable IPsec Anti-Replay. This option is not selected by default.
21
For Main Mode and Aggressive Mode only: To require XAUTH authentication by users prior to allowing traffic to traverse this tunnel, select Require authentication of VPN client by XAUTH. The User group for XAUTH users drop-down menu appears:

Select a User group to specify allowed users from the User group for XAUTH drop-down menu. You can create a new user group, also.
22
Select Enable Windows Networking (NetBIOS) Broadcast to allow access to remote network resources by browsing the Windows® Network Neighborhood.
23
Select Enable Multicast to allow IP multicasting traffic, such as streaming audio (including VoIP) and video applications, to pass through the VPN tunnel.
24
Select Permit Acceleration to enable redirection of traffic matching this policy to the WAN Acceleration (WXA) appliance.
25
Select Apply NAT Policies if you want the SonicWall to translate the Local, Remote or both networks communicating via this VPN tunnel. When this option is selected, two drop-down menus appear:

To perform Network Address Translation on the Local Network, select or create an Address Object in the Translated Local Network drop-down menu.
To translate the Remote Network, select or create an Address Object in the Translated Remote Network drop-down menu.
* 
NOTE: Generally, if NAT is required on a tunnel, either Local or Remote should be translated, but not both. Apply NAT Policies is particularly useful in cases where both sides of a tunnel use either the same or overlapping subnets.
26
For Main Mode and Aggressive Mode only: To enable SonicPointN Layer 3 Management, select Allow SonicPointN Layer 3 Management. This option is not selected by default.
27
For Main Mode and Aggressive Mode only: To enable Phase 2 Dead Peer Detection, select Phase 2 Dead Peer Detection. This option is not selected by default.
28
To manage the local SonicWall through the VPN tunnel, select one or more of the following from Management via this SA: None are selected by default.
HTTP
HTTPS
SSH
SNMP
29
Select HTTP, HTTPS, or both for User login via this SA to allow users to login using the SA.
30
If you wish to use a router on the LAN for traffic entering this tunnel destined for an unknown subnet, for example, if you configured the other side to Use this VPN Tunnel as default route for all Internet traffic or if you have more than one gateway and you want this one always to be used first, you should enter the IP address of your router into the Default LAN Gateway (optional) field.
31
Select an interface or zone from the VPN Policy bound to drop-down menu. A Zone WAN is the preferred selection if you are using WAN Load Balancing and you wish to allow the VPN to use either WAN interface. Zone WAN is the default.
* 
NOTE: Two different WAN interfaces cannot be bound to the same VPN Gateway IP address. To use multiple VPN tunnels to the same VPN peer, use a tunnel interface.
32
If you selected Main Mode or Aggressive Mode for Exchange in the Proposals tab, go to Step 35.
IKEv2 Settings section: IKEv2 Mode only
33
The Do not send trigger packet during IKE SA negotiation checkbox is not selected by default and should only be selected when required for interoperability if the peer cannot handle trigger packets.

The term Trigger Packet refers to the use of initial Traffic Selector payloads populated with the IP addresses from the packet that caused SA negotiation to begin. It is recommended practice to include Trigger Packets to assist the IKEv2 Responder in selecting the correct protected IP address ranges from its Security Policy Database. Not all implementations support this feature, so it may be appropriate to disable the inclusion of Trigger Packets to some IKE peers.

34
Select one or both of the following two options for the IKEv2 VPN policy:
Accept Hash & URL Certificate Type – When this option is selected, the firewall sends an HTTP_CERT_LOOKUP_SUPPORTED message to the peer device. If the peer device replies by sending a “Hash and URL of X.509c” certificate, the firewall can authenticate and establish a tunnel between the two devices.
Send Hash & URL Certificate Type – When this option is selected, the firewall, upon receiving an HTTP_CERT_LOOKUP_SUPPORTED message, sends a "Hash and URL of X.509c” certificate to the requestor.
* 
NOTE: In a VPN, two peer firewalls (FW1 and FW2) negotiate a tunnel. From the perspective of FW1, FW2 is the remote gateway and vice versa.

Select these options if your devices can send and process hash and certificate URLs instead of the certificates themselves. Using these options reduces the size of the messages exchanged.

35
Click OK.

Configuring a VPN Policy Using Manual Key

To manually configure a VPN policy between two SonicWall appliances using Manual Key, follow the steps below:

Configuring the Local SonicWall Security Appliance
1
Click Add on the VPN > Settings page. The VPN Policy dialog is displayed.
2
In the General tab of the VPN Policy window, select the policy type that you want.
3
Select Manual Key from the IPsec Keying Mode menu. The VPN Policy dialog displays the manual key options.

4
Enter a name for the policy in the Name field.
5
Enter the host name or IP address of the remote connection in the IPsec Gateway Name or Address field.
6
Click the Network tab.

7
Select a local network from Choose local network from list if a specific local network can access the VPN tunnel. If traffic can originate from any local network, select Any Address. Use this option is a peer has Use this VPN Tunnel as default route for all Internet traffic selected. You can only configure one SA to use this setting.

Alternatively, select Choose Destination network from list, and select the address object or group.

8
Click on the Proposals tab.

9
Define an Incoming SPI and an Outgoing SPI. The SPIs are hexadecimal (0123456789abcedf) and can range from 3 to 8 characters in length.
* 
CAUTION: Each Security Association must have unique SPIs; no two Security Associations can share the same SPIs. However, each Security Association Incoming SPI can be the same as the Outgoing SPI.
10
The default values for Protocol, Phase 2 Encryption, and Phase 2 Authentication are acceptable for most VPN SA configurations.
* 
NOTE: The values for Protocol, Phase 2 Encryption, and Phase 2 Authentication must match the values on the remote SonicWall.
11
Enter a 16-character hexadecimal encryption key in the Encryption Key field or use the default value. This encryption key is used to configure the remote SonicWall encryption key, therefore, write it down to use when configuring the SonicWall.
12
Enter a 32-character hexadecimal authentication key in the Authentication Key field or use the default value. Write down the key to use while configuring the SonicWall settings.
* 
TIP: Valid hexadecimal characters include 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, and f. 1234567890abcdef is an example of a valid DES or ARCFour encryption key. If you enter an incorrect encryption key, an error message is displayed at the bottom of the browser window.
13
Click the Advanced tab and select any of the following optional settings you want to apply to your VPN policy.

The Suppress automatic Access Rules creation for VPN Policy setting is not enabled by default to allow the VPN traffic to traverse the appropriate zones.
Select Enable Windows Networking (NetBIOS) broadcast to allow access to remote network resources by browsing the Windows® Network Neighborhood.
Select Apply NAT Policies if your want the SonicWall to translate the Local, Remote or both networks communicating via this VPN tunnel. To perform Network Address Translation on the Local Network, select or create an Address Object in the Translated Local Network drop-down box. To translate the Remote Network, select or create an Address Object in the Translated Remote Network drop-down box. Generally, if NAT is required on a tunnel, either Local or Remote should be translated, but not both. Apply NAT Policies is particularly useful in cases where both sides of a tunnel use either the same or overlapping subnets.
To manage the local SonicWall through the VPN tunnel, select HTTP, HTTPS, or both from Management via this SA.
Select HTTP, HTTPS, or both in the User login via this SA to allow users to login using the SA.
If you have an IP address for a gateway, enter it into the Default LAN Gateway (optional) field.
Select an interface from the VPN Policy bound to drop-down menu.
* 
NOTE: Two different WAN interfaces cannot be bound to the same VPN Gateway IP address. To use multiple VPN tunnels to the same VPN peer, use a tunnel interface.
14
Click OK.
15
Click Accept on the VPN > Settings page to update the VPN Policies.
Configuring the Remote SonicWall Security Appliance
1
Click Add on the VPN > Settings page. The VPN Policy dialog is displayed.
2
In the General tab, select Manual Key from the IPsec Keying Mode menu.
3
Enter a name for the SA in the Name field.
4
Enter the host name or IP address of the local connection in the IPsec Gateway Name or Address field.
5
Click the Network tab.
6
Select a local network from Choose local network from list if a specific local network can access the VPN tunnel. If traffic can originate from any local network, select Any Address. Select Use this VPN Tunnel as default route for all Internet traffic if traffic from any local user cannot leave the SonicWall security appliance unless it is encrypted. You can only configure one SA to use this setting.

Alternatively, select Choose Destination network from list, and select the address object or group.

7
Click the Proposals tab.
8
Define an Incoming SPI and an Outgoing SPI. The SPIs are hexadecimal (0123456789abcedf) and can range from 3 to 8 characters in length.
* 
CAUTION: Each Security Association must have unique SPIs; no two Security Associations can share the same SPIs. However, each Security Association Incoming SPI can be the same as the Outgoing SPI.
9
The default values for Protocol, Phase 2 Encryption, and Phase 2 Authentication are acceptable for most VPN SA configurations.
* 
NOTE: The values for Protocol, Phase 2 Encryption, and Phase 2 Authentication must match the values on the remote SonicWall.
10
Enter a 16 character hexadecimal encryption key in the Encryption Key field or use the default value. This encryption key is used to configure the remote SonicWall encryption key, therefore, write it down to use when configuring the remote SonicWall.
11
Enter a 32 character hexadecimal authentication key in the Authentication Key field or use the default value. Write down the key to use while configuring the remote SonicWall settings.
* 
TIP: Valid hexadecimal characters include 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, and f. 1234567890abcdef is an example of a valid DES or ARCFour encryption key. If you enter an incorrect encryption key, an error message is displayed at the bottom of the browser window.
12
Click the Advanced tab and select any of the following optional settings you want to apply to your VPN policy:
The Suppress automatic Access Rules creation for VPN Policy setting is not enabled by default to allow the VPN traffic to traverse the appropriate zones.
Select Enable Windows Networking (NetBIOS) broadcast to allow access to remote network resources by browsing the Windows® Network Neighborhood.
Select Apply NAT Policies if you want the SonicWall to translate the Local, Remote or both networks communicating via this VPN tunnel. To perform Network Address Translation on the Local Network, select or create an Address Object in the Translated Local Network drop-down box. To translate the Remote Network, select or create an Address Object in the Translated Remote Network drop-down box. Generally, if NAT is required on a tunnel, either Local or Remote should be translated, but not both. Apply NAT Policies is particularly useful in cases where both sides of a tunnel use either the same or overlapping subnets.
* 
CAUTION: You cannot use this feature if you have selected Use this VPN Tunnel as the default route for all Internet traffic on the Network tab.
To manage the remote SonicWall through the VPN tunnel, select HTTP, HTTPS, or both from Management via this SA.
Select HTTP, HTTPS, or both in the User login via this SA to allow users to login using the SA.
If you have an IP address for a gateway, enter it into the Default LAN Gateway (optional) field.
Select an interface from the VPN Policy bound to menu.
* 
NOTE: Two different WAN interfaces cannot be bound to the same VPN Gateway IP address. To use multiple VPN tunnels to the same VPN peer, use a tunnel interface.
13
Click OK.
14
Click Accept on the VPN > Settings page to update the VPN Policies.
* 
TIP: As Window Networking (NetBIOS) has been enabled, users can view remote computers in their Windows Network Neighborhood. Users can also access resources on the remote LAN by entering servers’ or workstations’ remote IP addresses.

Configuring a VPN Policy with IKE using a Third-Party Certificate

* 
CAUTION: You must have a valid certificate from a third party Certificate Authority installed on your SonicWall before you can configure your VPN policy with IKE using a third party certificate.
To create a VPN SA using IKE and third party certificates:
1
In the VPN > Settings page, click Add. The VPN Policy dialog is displayed.
2
In the Authentication Method list in the General tab, select IKE using 3rd Party Certificates.The VPN Policy dialog displays the 3rd party certificate options.

3
Type a Name for the Security Association in the Name field.
4
Type the IP address or Fully Qualified Domain Name (FQDN) of the primary remote SonicWall in the IPsec Primary Gateway Name or Address field. If you have a secondary remote SonicWall, enter the IP address or Fully Qualified Domain Name (FQDN) in the IPsec Secondary Gateway Name or Address field.
5
Under IKE Authentication, select a third party certificate from the Local Certificate list. You must have imported local certificates before selecting this option.
6
Select one of the following Peer ID types from the Peer IKE ID Type menu:
E-Mail ID and Domain Name - The Email ID and Domain Name types are based on the certificate's Subject Alternative Name field, which is not contained in all certificates by default. If the certificate contains a Subject Alternative Name, that value must be used. For site-to-site VPNs, wild card characters (such as * for more than 1 character or ? for a single character) cannot be used. The full value of the E-Mail ID or Domain Name must be entered. This is because site-to-site VPNs are expected to connect to a single peer, as opposed to Group VPNs, which expect multiple peers to connect.
Distinguished Name - Based on the certificates Subject Distinguished Name field, which is contained in all certificates by default. As with the E-Mail ID and Domain Name above, the entire Distinguished Name field must be entered for site-to-site VPNs Wild card characters are not supported.

The format of any Subject Distinguished Name is determined by the issuing Certificate Authority. Common fields are Country (C=), Organization (O=), Organizational Unit (OU=), Common Name (CN=), Locality (L=), and vary with the issuing Certificate Authority. The actual Subject Distinguished Name field in an X.509 Certificate is a binary object which must be converted to a string for matching purposes. The fields are separated by the forward slash character, for example: /C=US/O=SonicWall, Inc./OU=TechPubs/CN=Joe Pub

To find the certificate details (Subject Alternative Name, Distinguished Name, etc.), navigate to the System > Certificates page and click on the Export button for the certificate.
7
Type an ID string in the Peer IKE ID field.
8
Click on the Network tab.

9
Under Local Networks, select a local network from Choose local network from list if a specific local network can access the VPN tunnel. If hosts on this side of the VPN connection will be obtaining their addressing from a DHCP server on the remote side of the tunnel, select Local network obtains IP addresses using DHCP through this VPN tunnel. If traffic can originate from any local network, select Any Address.
10
Under Destination Networks, select Use this VPN Tunnel as default route for all Internet traffic if traffic from any local user cannot leave the SonicWall security appliance unless it is encrypted. You can only configure one SA to use this setting. If the remote side of this VPN connection is be obtaining its addressing from a DHCP server on this side of the tunnel, select Destination network obtains IP addresses using DHCP server through this tunnel.

Alternatively, select Choose Destination network from list, and select the address object or group.

11
Click the Proposals tab.

12
In the IKE (Phase 1) Proposal section, select the following settings:
Select Main Mode or Aggressive Mode from the Exchange drop-down menu.
Select the desired DH Group from the DH Group drop-down menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Select 3DES, AES-128, AES-192, or AES-256 from the Encryption drop-down menu.
Select the desired authentication method from the Authentication drop-down menu.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
13
In the IPsec (Phase 2) Proposal section, select the following settings:
Select the desired protocol from the Protocol drop-down menu.
Select 3DES, AES-128, AES-192, or AES-256 from the Encryption drop-down menu.
Select the desired authentication method from the Authentication drop-down menu.
Select Enable Perfect Forward Secrecy if you want an additional Diffie-Hellman key exchange as an added layer of security. Select Group 2 from the DH Group menu.
* 
NOTE: The Windows 2000 L2TP client and Windows XP L2TP client can only work with DH Group 2. They are incompatible with DH Groups 1 and 5.
Enter a value in the Life Time (seconds) field. The default setting of 28800 forces the tunnel to renegotiate and exchange keys every 8 hours.
14
Click the Advanced tab. Select any optional configuration options you want to apply to your VPN policy:

Select Enable Keep Alive to use heartbeat messages between peers on this VPN tunnel. If one end of the tunnel fails, using Keepalives will allow for the automatic renegotiation of the tunnel once both sides become available again without having to wait for the proposed Life Time to expire.
The Suppress automatic Access Rules creation for VPN Policy setting is not enabled by default to allow the VPN traffic to traverse the appropriate zones.
To require XAUTH authentication by users prior to allowing traffic to traverse this tunnel, select Require authentication of VPN client by XAUTH, and select a User group to specify allowed users from the User group for XAUTH.
Select Enable Windows Networking (NetBIOS) Broadcast to allow access to remote network resources by browsing the Windows® Network Neighborhood.
Select Enable Multicast to allow multicast traffic through the VPN tunnel.
Select Permit Acceleration to enable redirection of traffic matching this policy to the WAN Acceleration (WXA) appliance.
Select Apply NAT Policies if you want the SonicWall to translate the Local, Remote or both networks communicating via this VPN tunnel. To:
Perform Network Address Translation on the Local Network, select or create an Address Object in the Translated Local Network menu.
Translate the Remote Network, select or create an Address Object in the Translated Remote Network menu. Generally, if NAT is required on a tunnel, either Local or Remote should be translated, but not both.

Apply NAT Policies is particularly useful where both sides of a tunnel use either the same or overlapping subnets.

Select Enable OCSP Checking to check VPN certificate status and specify the URL where to check certificate status. See the Using OCSP with SonicWall Security Appliances.
To manage the remote SonicWall through the VPN tunnel, select HTTP, HTTPS, or both from Management via this SA. Select HTTP, HTTPS, or both in the User login via this SA to allow users to login using the SA.
If you wish to use a router on the LAN for traffic entering this tunnel destined for an unknown subnet, for example, if you configured the other side to Use this VPN Tunnel as default route for all Internet traffic, you should enter the IP address of your router into the Default LAN Gateway (optional) field.
Select an interface or zone from the VPN Policy bound to drop-down menu. A zone is the preferred selection if you are using WAN Load Balancing and you wish to allow the VPN to use either WAN interface.
* 
NOTE: Two different WAN interfaces cannot be bound to the same VPN Gateway IP address. To use multiple VPN tunnels to the same VPN peer, use a tunnel interface.
15
Click OK.

Configuring VPN Failover to a Static Route

Optionally, you can configure a static route to be used as a backup route in case the VPN tunnel goes down. The Allow VPN path to take precedence option allows you to create a backup route for a VPN tunnel. By default, static routes have a metric of one and take precedence over VPN traffic. The Allow VPN path to take precedence option gives precedence over the route to VPN traffic to the same destination address object. This results in the following behavior:

When a VPN tunnel is active: static routes matching the destination address object of the VPN tunnel are automatically disabled if the Allow VPN path to take precedence option is enabled. All traffic is routed over the VPN tunnel to the destination address object.
When a VPN tunnel goes down: static routes matching the destination address object of the VPN tunnel are automatically enabled. All traffic to the destination address object is routed over the static routes.
To configure a static route as a VPN failover:
1
Navigate to the Network > Routing page.
2
Scroll to the bottom of the page and click on the Add button. The Add Route Policy dialog is displayed.
3
Select the appropriate Source, Destination, Service, Gateway, and Interface.
4
Leave the Metric as 1.
5
Enable the Allow VPN path to take precedence check box.
6
Click OK.

Route Based VPN

A policy-based approach forces the VPN policy configuration to include the network topology configuration. This makes it difficult for the network administrator to configure and maintain the VPN policy with a constantly changing network topology.

With the Route Based VPN approach, network topology configuration is removed from the VPN policy configuration. The VPN policy configuration creates a Tunnel Interface between two end points. Static or Dynamic routes can then be added to the Tunnel Interface. The Route Based VPN approach moves network configuration from the VPN policy configuration to Static or Dynamic Route configuration.

Not only does Route Based VPN make configuring and maintaining the VPN policy easier, a major advantage of the Route Based VPN feature is that it provides flexibility on how traffic is routed. With this feature, users can now define multiple paths for overlapping networks over a clear or redundant VPN.

Topics:

Using Route Based VPN

Route Based VPN configuration is a two step process. The first step involves creating a Tunnel Interface. The crypto suites used to secure the traffic between two end-points are defined in the Tunnel Interface. The second step involves creating a static or dynamic route using Tunnel Interface.

The Tunnel Interface is created when a Policy of type “Tunnel Interface” is added for the remote gateway. The Tunnel Interface must be bound to a physical interface and the IP address of that physical interface is used as the source address of the tunneled packet.

Adding a Tunnel Interface

To add a Tunnel Interface:
1
Navigate to VPN > Settings.
2
In the VPN Policies section, click the Add button. The VPN Policy dialog displays.

* 
NOTE: This procedure is based on using an IKE authentication method. If Manual Key is selected for Authentication Method, all IKE options are removed.
3
On the General tab, select the policy type as Tunnel Interface. The IPsec Secondary Gateway name or Address option and the Network tab are removed.

4
Click the Proposals tab.

5
Configure the IKE (Phase 1) Proposal and IPsec (Phase 2) Proposal options for the tunnel negotiation.
6
Click the Advanced tab to configure the advanced properties for the Tunnel Interface. By default, Enable Keep Alive is enabled. This is to establish the tunnel with remote gateway proactively.

7
The following other advanced options can be configured:
Disable IPsec Anti-Replay - Disables anti-replay, which is a form of partial sequence integrity that detects the arrival of duplicate IP datagrams (within a constrained window).
Enable Windows Networking (NetBIOS) Broadcast - Allows access to remote network resources by browsing the Windows® Network Neighborhood.
Enable Multicast - Allows multicast traffic through the VPN tunnel.
Permit Acceleration - Enables redirection of traffic matching this policy to the WAN Acceleration (WXA) appliance
Management via this SA - Allows remote users to log in to manage the SonicWall through the VPN tunnel. Select one or more: HTTP, HTTPS, SSH, SNMP.
User login via this SA - Allows users to login using the SA. Select one or both: HTTP (this may be dimmed and, therefore, unavailable) or HTTPS.
VPN Policy bound to - Sets the interface the Tunnel Interface is bound to. This is Interface X1 by default. Two different WAN interfaces cannot be selected from the VPN Policy bound to drop-down menu if the VPN Gateway IP address is the same for both.
8
If IKEv2 Mode was selected on the Proposals tab, configure the IKEv2 Settings:
The Do not send trigger packet during IKE SA negotiation check box is not selected by default and should be selected only when required for interoperability if the peer cannot handle trigger packets.

The term Trigger Packet refers to the use of initial Traffic Selector payloads populated with the IP addresses from the packet that caused SA negotiation to begin. It is recommended practice to include Trigger Packets to assist the IKEv2 Responder in selecting the correct protected IP address ranges from its Security Policy Database. Not all implementations support this feature, so it may be appropriate to disable the inclusion of Trigger Packets to some IKE peers.

Select one or both of the following two options for the IKEv2 VPN policy:
Accept Hash & URL Certificate Type – The firewall sends an HTTP_CERT_LOOKUP_SUPPORTED message to the peer device. If the peer device replies by sending a “Hash and URL of X.509c” certificate, the firewall can authenticate and establish a tunnel between the two devices.
Send Hash & URL Certificate Type – The firewall, on receiving an HTTP_CERT_LOOKUP_SUPPORTED message, sends a "Hash and URL of X.509c” certificate to the requestor.

When this option is selected, enter the URL for a certificate in the Certificate URL field.

Select these options if your devices can send and process hash and certificate URLs instead of the certificates themselves. Using these options reduces the size of the messages exchanged.

In a VPN, two peer firewalls (FW1 and FW2) negotiate a tunnel. From the perspective of FW1, FW2 is the remote gateway and vice versa.

9
Click OK.

Creating a Static Route for Tunnel Interface

After you have successfully added a Tunnel Interface, you can then create a Static Route.

Topics:
Creating a Static Route for a Tunnel Interface
To create a Static Route for a Tunnel Interface:
1
Navigate to Network > Routing.
2
In the Route Policies section, click the Add button. The Add Route Policy dialog displays.

3
Select an interface from the Interface drop-down menu, which lists all available tunnel interfaces.
* 
NOTE: If the “Auto-add Access Rule” option is selected, firewall rules are automatically added and traffic is allowed between the configured networks using tunnel interface.
Route Entries for Different Network Segments

After a tunnel interface is created, multiple route entries can be configured to use the same tunnel interface for different networks. This provides a mechanism to modify the network topology without making any changes to the tunnel interface.

The image below shows an example of same tunnel interface for different networks (Routes 1 & 2):

Redundant Static Routes for a Network

After more than one tunnel interface is configured, you can add multiple overlapping static routes; each static route uses a different tunnel interface to route the traffic. This provides routing redundancy for the traffic to reach the destination.

The image below illustrates redundant static routes for a network (Routes 2 & 3):

Drop Tunnel Interface

The drop tunnel interface is a pre-configured tunnel interface. This interface provides added security for traffic. An example of this would be if a static route bind interface is deemed the drop tunnel interface, then all the traffic for that route is dropped and not forwarded in clear. If a static route bind to tunnel interface is defined for traffic (source/destination/service), and it is desired that traffic should not be forwarded in the clear if the tunnel interface is down, it is recommended to configure a static route bind to drop tunnel interface for the same network traffic. As a result, if the tunnel interface is down, traffic will be dropped due to the drop tunnel interface static route.

Creating a Static Route for Drop Tunnel Interface
To add a static route for drop tunnel interface:
1
Navigate to Network > Routing > Routing Policies.
2
Click the Add button.
3
Similar to configuring a static route for a tunnel interface, configure the values for Source, Destination, and Service Objects. Under Interface, select “Drop_tunnelIf.”

Once added, the route is enabled and displayed in the Route Polices.

Configuring a Numbered VPN Tunnel Interface

Routing protocols can use a numbered tunnel interface to establish a routing session. To support this requirement, SonicOS must add an interface in the VPN zone with an IP address from a private subnet assigned to it. This numbered tunnel interface can be used for the routing protocol session.

After a numbered tunnel interface is added to the interface list, a static route policy can use it as the interface in a static route policy configuration for a static route based VPN. Routing protocols (OSPF, RIP, and BGP) can use it for dynamic route based VPN.

* 
NOTE: Numbered tunnel interfaces are not supported on the NSA 2400MX, SOHO, and TZ 210/205/200/105/100 series platforms.

Configuring a Numbered VPN Tunnel Interface is done in two parts:

Configuring the VPN Policy
Configuring the Tunnel Interface
* 
NOTE: A similar VPN policy and numbered tunnel interface must be configured on the remote gateway. The IP addresses assigned to the numbered tunnel interfaces (on the local gateway and the remote gateways) must be on the same subnet.
Topics:
Configuring the VPN Policy
To configure a Numbered VPN Tunnel Interface:
1
Go to the VPN > Settings page.
2
In the VPN Policies panel, click the Add button. The VPN Policy dialog appears.

3
From the Policy Type menu, select Tunnel Interface.
4
From the Authentication Method menu, select IKE using Preshared Secret.
5
In the Name box, enter the name of the policy.
6
In the IPsec Primary Gateway Name or Address box, enter the name or the IP address of the primary gateway.
7
In the Shared Secret and Confirm Shared Secret boxes, enter your shared secret.
8
Click OK.
Configuring the Tunnel Interface
1
Go to the Network > Interfaces page.

2
From the Add Interface menu, select Tunnel Interface. The Add Tunnel Interface dialog appears.

3
From the Zone drop-down menu, select VPN.
4
From the VPN Policy drop-down menu, select the VPN Policy that you just created.
5
From the Mode / IP Assignment drop-down menu, select Static IP Mode.
6
In the IP Address check box, enter the IP address for the interface.
7
In the Subnet Mask check box, enter the subnet mask.
8
Click OK.

The numbered VPN tunnel interface should appear on the Network > Interfaces page and on the Network > Routing page when you select Advanced Routing from the Routing Mode drop-down menu.

VPN Auto-Added Access Rule Control

When adding VPN Policies, SonicOS auto-creates non-editable Access Rules to allow the traffic to traverse the appropriate zones. Consider the following VPN Policy, where the Local Network is set to Firewalled Subnets (in this case comprising the LAN and DMZ) and the Destination Network is set to Subnet 192.168.169.0.

While this is generally a tremendous convenience, there are some instances where is might be preferable to suppress the auto-creation of Access Rules in support of a VPN Policy. One such instance would be the case of a large hub-and-spoke VPN deployment where all the spoke site are addresses using address spaces that can easily be supernetted. For example, assume we wanted to provide access to/from the LAN and DMZ at the hub site to one subnet at each of 2,000 remote sites, addressed as follows:

remoteSubnet0=Network 10.0.0.0/24 (mask 255.255.255.0, range 10.0.0.0-10.0.0.255)
remoteSubnet1=Network 10.0.1.0/24 (mask 255.255.255.0, range 10.0.1.0-10.0.1.255)
remoteSubnet2=Network 10.0.2.0/24 (mask 255.255.255.0, range 10.0.2.0-10.0.2.255)
remoteSubnet2000=10.7.207.0/24 (mask 255.255.255.0, range 10.7.207.0-10.7.207.255)

Creating VPN Policies for each of these remote sites would result in the requisite 2,000 VPN Policies, but would also create 8,000 Access Rules (LAN -> VPN, DMZ -> VPN, VPN -> LAN, and VPN -> DMZ for each site). However, all of these Access Rules could easily be handled with just 4 Access Rules to a supernetted or address range representation of the remote sites (More specific allow or deny Access Rules could be added as needed):

remoteSubnetAll=Network 10.0.0.0/13 (mask 255.248.0.0, range 10.0.0.0-10.7.255.255)
or
remoteRangeAll=Range 10.0.0.0-10.7.207.255

To enable this level of aggregation, the Advanced tab of the VPN Policy window page offers the option to Auto-Add Access Rules for VPN Policy setting. By default, the check box is selected, meaning the accompanying Access Rules will be automatically created, as they've always been. By deselecting the check box upon creating the VPN Policy, the administrator will have the ability and need to create custom Access Rules for VPN traffic.

Configuring Advanced VPN Settings

VPN > Advanced

The VPN > Advanced page includes optional settings that affect all VPN policies.

Topics:

Advanced VPN Settings

Enable IKE Dead Peer Detection - Select if you want inactive VPN tunnels to be dropped by the SonicWall. Default is enabled.
Dead Peer Detection Interval - Enter the number of seconds between “heartbeats.” The minimum is 3 seconds, the maximum is 120 seconds, and the default value is 60 seconds.
Failure Trigger Level (missed heartbeats) - Enter the number of missed heartbeats. The minimum is 3 heartbeats, the maximum is 10, and the default value is 3.

If the trigger level is reached, the VPN connection is dropped by the SonicWall security appliance. The SonicWall security appliance uses a UDP packet protected by Phase 1 Encryption as the heartbeat.

Enable Dead Peer Detection for Idle VPN Sessions - Select this setting if you want idle VPN connections to be dropped by the SonicWall security appliance after the time value defined in the Dead Peer Detection Interval for Idle VPN Sessions (seconds) field. The minimum time is 60 seconds, the maximum is 3600 seconds, and the default value is 600 seconds (10 minutes).
Enable Fragmented Packet Handling - If the VPN log report shows the log message, Fragmented IPsec packet dropped, select this feature. Do not select it until the VPN tunnel is established and in operation.
Ignore DF (Don't Fragment) Bit - Select this check box to ignore the DF (Don’t Fragment the packet) bit in the packet header. Some applications can explicitly set the Don’t Fragment option in a packet, which tells all security appliances to not fragment the packet. This option, when enabled, causes the SonicWall to ignore the option and fragment the packet regardless. If this option is not set, packets that exceed the PMTU and have the DF bit enabled are not forwarded. Instead, this message is returned to the sender: Fragmentation needed and do not fragment (DF) bit set.
Enable NAT Traversal - Select this setting if a NAT device is located between your VPN endpoints. IPsec VPNs protect traffic exchanged between authenticated endpoints, but authenticated endpoints cannot be dynamically re-mapped mid-session for NAT traversal to work. Therefore, to preserve a dynamic NAT binding for the life of an IPsec session, a 1-byte UDP is designated as a “NAT Traversal keepalive” and acts as a “heartbeat” sent by the VPN device behind the NAT or NAPT device. The “keepalive” is silently discarded by the IPsec peer.
Clean up Active Tunnels when Peer Gateway DNS name resolves to a different IP address - When selected, this option breaks down SAs associated with old IP addresses and reconnects the SA to the peer. The default is enabled.
Preserve IKE Port for Pass-Through Connections - Preserves UDP 500/4500 source port and IP address information for pass-through VPN connections.
Enable OCSP Checking and OCSP Responder URL - Enables use of Online Certificate Status Protocol (OCSP) to check VPN certificate status and specifies the URL where to check certificate status. For more information, see Using OCSP with SonicWall Security Appliances.
Send VPN Tunnel Traps only when tunnel status changes - Reduces the number of VPN tunnel traps that are sent by only sending traps when the tunnel status changes.
Use RADIUS in <mode> mode for XAUTH (allows users to change expired passwords) - Select the MSCHAP version to use with RADIUS:
MSCHAP (default)
MSCHAPv2

When using RADUIS to authenticate VPN client users, RADIUS is used in its MSCHAP (or MSCHAPv2) mode. The primary reason for choosing to do this is so VPN client users can make use of the MSCHAP feature to allow them to change expired passwords at login time.

Also, if this option is set and LDAP is selected as the Authentication method for login on the Users > Settings page, but LDAP is not configured in a way that allows password updates, then password updates for VPN client users are done using MSCHAP-mode RADIUS after using LDAP to authenticate the user.

* 
NOTE: Password updates can only be done by LDAP when using either:
Active Directory with TLS and binding to it using an administrative account.
Novell eDirectory.
DNS and WINS Server Settings for VPN Client - Configure the DNS and WINS server settings for clients (such as third-party VPN clients) through GroupVPN or Mobile IKEv2 client. Clicking the Configure button launches the Add VPN DNS and WINS Server dialog:

DNS Servers — Configure DNS servers:
Inherit DNS Settings Dynamically using SonicWall’s DNS settings — Selecting this option automatically populates the DNS and WINS settings with the settings in the Network > DNS page. This option is selected by default.
Specify Manually — If you do not want to use the SonicWall security appliance network settings, select Specify Manually, and type the IP address of your DNS Server in the DNS Server 1 field. You can specify two additional DNS servers.
WINS Servers — Configure a WINS server in the WINS Server 1 field. You can configure a second WINS server, also.

IKEv2 Settings

Send IKEv2 Cookie Notify - Sends cookies to IKEv2 peers as an authentication tool. This option is not selected by default.
Send IKEv2 Invalid SPI Notify – Sends an invalid SPI to IKEv2 peers when the active IKE SA exists. This option is selected by default.
IKEv2 Dynamic Client Proposal - SonicOS Enhanced firmware versions 4.0 and higher provide IKEv2 Dynamic Client Support, which provides a way to configure the Internet Key Exchange (IKE) attributes rather than using the default settings. Clicking the Configure button launches the Configure IKEv2 Dynamic Client Proposal dialog.

Previously, only the default settings were supported: Diffie-Hellman (DH) Group 2, the 3DES encryption algorithm, and the SHA1 authentication method. SonicOS now allows the following IKE Proposal settings:

DH Group: Group 1, Group 2, Group 5, or Group 14
Encryption: DES, 3DES, AES-128, AES-192, AES-256
Authentication: MD5, SHA1, SHA256, SHA384, SHA512

However, if a VPN Policy with IKEv2 exchange mode and a 0.0.0.0 IPsec gateway is defined, you cannot configure these IKE Proposal settings on an individual policy basis.

* 
NOTE: The VPN policy on the remote gateway must also be configured with the same settings.

Using OCSP with SonicWall Security Appliances

Online Certificate Status Protocol (OCSP) allows you to check VPN certificate status without CRLs. This allows timely updates regarding the status of the certificates used on your SonicWall.

Topics:

About OCSP

OCSP is designed to augment or replace Certificate Revocation Lists (CRL) in your Public Key Infrastructure (PKI) or digital certificate system. The CRL is used to validate the digital certificates comprised by the PKI. This allows the Certificate Authority (CA) to revoke certificates before their scheduled expiration date and is useful in protecting the PKI system against stolen or invalid certificates.

The main disadvantage of Certificate Revocation Lists is the need for frequent updates to keep the CRL of every client current. These frequent updates greatly increase network traffic when the complete CRL is downloaded by every client. Depending on the frequency of the CRL updates, a period of time can exist when a certificate is revoked by the CRL but the client has not received the CRL update and permits the certificate to be used.

Online Certificate Status Protocol determines the current status of a digital certificate without using a CRL. OCSP enables the client or application to directly determine the status of an identified digital certificate. This provides more timely information about the certificate than is possible with CRLs. In addition, each client typically only checks a few certificates and does not incur the overhead of downloading an entire CRL for only a few entries. This greatly reduces the network traffic associated with certificate validation.

OCSP transports messages over HTTP for maximum compatibility with existing networks. This requires careful configuration of any caching servers in the network to avoid receiving a cached copy of an OCSP response that might be out of date.

The OCSP client communicates with an OCSP responder. The OCSP responder can be a CA server or another server that communicates with the CA server to determine the certificate status. The OCSP client issues a status request to an OCSP responder and suspends the acceptance of the certificate until the responder provides a response. The client request includes data such as protocol version, service request, target certificate identification and optional extensions. These optional extensions may or may not be acknowledged by the OCSP responder.

The OCSP responder receives the request from the client and checks that the message is properly formed and if the responder is able to respond to the service request. Then it checks if the request contains the correct information needed for the service desired. If all conditions are satisfied, the responder returns a definitive response to the OCSP client. The OCSP responder is required to provide a basic response of GOOD, REVOKED, or UNKNOWN. If both the OCSP client and responder support the optional extensions, other responses are possible. The GOOD state is the desired response as it indicates the certificate has not been revoked. The REVOKED state indicates that the certificate has been revoked. The UNKNOWN state indicates the responder does not have information about the certificate in question.

OCSP servers typically work with a CA server in push or pull setup. The CA server can be configured to push a CRL list (revocation list) to the OCSP server. Additionally the OCSP server can be configured to periodically download (pull) the CRL from the CA server. The OCSP server must also be configured with an OCSP response signing certificate issued by the CA server. The signing certificate must be properly formatted or the OCSP client will not accept the response from the OCSP server.

OpenCA OCSP Responder

Using OCSP requires the OpenCA (OpenSource Certificate Authority) OpenCA OCSP Responder as it is the only supported OCSP responder.

OpenCA OCSP Responder is available at http://www.openca.org/.

The OpenCA OCSP Responder is an rfc2560 compliant OCSP responder that runs on a default port of 2560 in homage to being based on rfc2560.

Loading Certificates to use with OCSP

For SonicOS to act as an OCSP client to a responder, the CA certificate must be loaded onto the SonicWall.

1
On the System -> Certificates page, click on the Import button. This will bring up the Import Certificate page.
2
Select the Import a CA certificate from a PKCS#7 (.p7b), PEM (.pem) or DER (.der or .cer) encoded file option and specify the location of the certificate.

Using OCSP with VPN Policies

The SonicWall OCSP settings can be configured on a policy level or globally. To configure OCSP checking for individual VPN policies, use the Advanced tab of the VPN Policy configuration page.

1
Select the radio button next to Enable OCSP Checking.
2
Specify the OCSP Responder URL of the OCSP server, for example, http://192.168.168.220:2560, where 192.168.168.220 is the IP address of your OCSP server and 2560 is the default port of operation for the OpenCA OCSP responder service.

Configuring DHCP Over VPN

VPN > DHCP over VPN

The VPN > DHCP over VPN page allows you to configure a SonicWall security appliance to obtain an IP address lease from a DHCP server at the other end of a VPN tunnel. In some network deployments, it is desirable to have all VPN networks on one logical IP subnet, and create the appearance of all VPN networks residing in one IP subnet address space. This facilitates IP address administration for the networks using VPN tunnels.

Topics:

DHCP Relay Mode

The SonicWall security appliance at the remote and central site are configured for VPN tunnels for initial DHCP traffic as well as subsequent IP traffic between the sites. The SonicWall security appliance at the remote site (Remote Gateway) passes DHCP broadcast packets through its VPN tunnel. The SonicWall security appliance at the central site (Central Gateway) relays DHCP packets from the client on the remote network to the DHCP server on the central site.

Configuring the Central Gateway for DHCP Over VPN

To configure DHCP over VPN for the Central Gateway:
1
Go to the VPN > DHCP over VPN page.

2
From the DHCP over VPN menu, select Central Gateway.
3
Click Configure.
4
The DHCP over VPN Configuration dialog appears.

5
To enable the SonicWall Global VPN Client, or a remote firewall, or both to use an internal DHCP server to obtain IP addresses, select the Use Internal DHCP Server option.
6
To use the DHCP Server for Global VPN Clients, select the For Global VPN Client option.
7
To send DHCP requests to specific servers, select the Send DHCP requests to the server addresses listed below option.
8
Click the Add button. The Add DHCP Server dialog appears.
9
Enter the IP addresses of DHCP servers in the IP Address field, and click OK. The SonicWall security appliance now directs DHCP requests to the specified servers.
10
In the Relay IP Address (Optional) box, enter the IP address of the relay server.
11
To edit an entry in the IP Address table, click Edit. To delete a DHCP Server, highlight the entry in the IP Address table, and click Delete. Click Delete All to delete all entries.

Configuring DHCP over VPN Remote Gateway

1
Select Remote Gateway from the DHCP Relay Mode menu.
2
Click Configure. The DHCP over VPN Configuration dialog displays.

3
In the General tab, the VPN policy name is automatically displayed in the Relay DHCP through this VPN Tunnel field if the VPN policy has the setting Local network obtains IP addresses using DHCP through this VPN Tunnel enabled.
* 
NOTE: Only VPN policies using IKE can be used as VPN tunnels for DHCP.
4
Select the interface the DHCP lease is bound from the DHCP lease bound to menu.
5
To accept DHCP requests from bridged WLAN interfaces, click the check box for Accept DHCP Request from bridged WLAN interface.
6
If you enter an IP address in the Relay IP address field, this IP address is used as the DHCP Relay Agent IP address in place of the Central Gateway’s address, and must be reserved in the DHCP scope on the DHCP server. This address can also be used to manage this SonicWall security appliance remotely through the VPN tunnel from behind the Central Gateway.
7
If you enter an IP address in the Remote Management IP Address field, this IP address is used to manage the SonicWall security appliance from behind the Central Gateway, and must be reserved in the DHCP scope on the DHCP server.
8
If you enable Block traffic through tunnel when IP spoof detected, the SonicWall security appliance blocks any traffic across the VPN tunnel that is spoofing an authenticated user’s IP address. If you have any static devices, however, you must ensure that the correct Ethernet address is typed for the device. The Ethernet address is used as part of the identification process, and an incorrect Ethernet address can cause the SonicWall security appliance to respond to IP spoofs.
9
If the VPN tunnel is disrupted, temporary DHCP leases can be obtained from the local DHCP server. Once the tunnel is again active, the local DHCP server stops issuing leases. Enable the Obtain temporary lease from local DHCP server if tunnel is down check box. By enabling this check box, you have a failover option in case the tunnel ceases to function.
10
If you want to allow temporary leases for a certain time period, type the number of minutes for the temporary lease in the Temporary Lease Time box. The default value is 2 minutes.

Configuring Devices on a LAN

To configure devices on a LAN:
1
Click the Devices tab in the DHCP over VPN Configuration window.

2
To configure Static Devices on the LAN, click Add to display the Add LAN Device Entry window, and type the IP address of the device in the IP Address field and then type the Ethernet address of the device in the Ethernet Address field.

An example of a static device is a printer as it cannot obtain an IP lease dynamically. If you do not have Block traffic through tunnel when IP spoof detected enabled, it is not necessary to type the Ethernet address of a device. You must exclude the Static IP addresses from the pool of available IP addresses on the DHCP server so that the DHCP server does not assign these addresses to DHCP clients. You should also exclude the IP address used as the Relay IP Address. It is recommended to reserve a block of IP address to use as Relay IP addresses.

3
Click OK.
4
To exclude devices on your LAN, click the Add button for the Add Excluded LAN Entry table. Enter the MAC address of the device in the Ethernet Address field of the displayed Add Excluded LAN Entry window.
5
Click OK.
6
Click OK to exit the DHCP over VPN Configuration window.
* 
NOTE: You must configure the local DHCP server on the remote SonicWall security appliance to assign IP leases to these computers.
* 
NOTE: If a remote site has trouble connecting to a central gateway and obtaining a lease, verify that Deterministic Network Enhancer (DNE) is not enabled on the remote computer.
* 
TIP: If a static LAN IP address is outside of the DHCP scope, routing is possible to this IP, that is, two LANs.

Current DHCP over VPN Leases

The scrolling window shows the details on the current bindings: IP and Ethernet address of the bindings, along with the Lease Time, and Tunnel Name.

To delete a binding, which frees the IP address in the DHCP server, select the binding from the list, and then click the Delete icon. The operation takes a few seconds to complete. Once completed, a message confirming the update is displayed at the bottom of the Web browser window.

Click Delete All to delete all VPN leases.

Configuring L2TP Server

VPN > L2TP Server

The SonicWall security appliance can terminate L2TP-over-IPsec connections from incoming Microsoft Windows 2000 and Windows XP clients. In situations where running the SonicWall Global VPN Client is not possible, you can use the SonicWall L2TP Server to provide secure access to resources behind the SonicWall security appliances.

You can use Layer 2 Tunneling Protocol (L2TP) to create VPN over public networks such as the Internet. L2TP provides interoperability between different VPN vendors that protocols such as PPTP and L2F do not, although L2TP combines the best of both protocols and is an extension of them. L2TP is supported on Microsoft Windows 2000 Operating System.

L2TP supports several of the authentication options supported by PPP, including Password Authentication Protocol (PAP), Challenge Handshake Authentication Protocol (CHAP), and Microsoft Challenge Handshake Authentication Protocol (MS-CHAP). You can use L2TP to authenticate the endpoints of a VPN tunnel to provide additional security, and you can implement it with IPsec to provide a secure, encrypted VPN solution.

* 
NOTE: For more complete information on configuring the L2TP Server, see the technote Configuring the L2TP Server in SonicOS located on the SonicWall documentation site:
http://www.SonicWall.com/us/Support.html.
Topics:

Configuring the L2TP Server

The VPN > L2TP Server page provides the settings for configuring the SonicWall security appliance as an L2TP Server.

To configure a SonicWall security appliance as an L2TP Server:
1
On the SonicWall security appliance, go to the VPN > L2TP Server page.
2
Select the Enable L2TP Server option.
3
Click the Configure button. The L2TP Server Configuration dialog appears.

4
Under the L2TP Server tab, in the Keep alive time (secs) box, enter the number of seconds to keep the connection open by sending special packets. The minimum time is 1 second, the maximum is 999 seconds, and the default is 60 seconds.
5
In the DNS Server 1 box, enter the IP address of your first DNS server.
6
If you have a second DNS server, in the DNS Server 2 box, enter the IP address of your second DNS server.
7
In the WINS Server 1 box, enter the IP address of your first WINS server.
8
If you have a second WINS server, in the WINS Server 2 box, enter the IP address of your second WINS server.
9
Click the L2TP User tab,

10
If a RADIUS Server provides the IP addresses for the L2TP clients, select the IP address provided by RADIUS Server option.
11
If an L2TP Server provides the IP addresses for the L2TP clients, select the Use the Local L2TP IP pool option.
12
In the Start IP and End IP boxes, enter the range of private IP addresses. The private IP addresses should be a range of IP addresses on the LAN.
13
From the User Group for L2TP users menu, if you have configured a specific user group defined for using L2TP, select it from the User Group for L2TP users menu, or select one of the other options, such as Everyone.
14
Click the PPP tab.

15
To reorder the authentication protocols, select a protocol and then click the up or down arrow to move the protocol into position.
16
To add a protocol, click the Add button.
17
To remove a protocol, select it and then click the Remove button.
18
Click OK.

Currently Active L2TP Sessions

User Name - The user name assigned in the local user database or the RADIUS user database.
PPP IP - The source IP address of the connection.
Zone - The zone used by the L2TP client.
Interface - The interface used to access the L2TP Server, whether it is a VPN client or another SonicWall security appliance.
Authentication - Type of authentication used by the L2TP client.
Host Name - The name of the L2Tp client connecting to the L2TP Server.