Routing Internet traffic through a remote SonicWall device which is in another network

12/20/2019 73 20700

DESCRIPTION:

There are two SonicWalls, Site A and Site B.

• Site A and Site B are connected by using a point to point link layer 2 device.
• Site A's X5 Interface was assigned to the LAN Zone, which means that by default Site B has access to Site A's LAN .
• There is no existing VPN between Site A and Site B.
• The Internet traffic from the Site B network has to go through the Site A SonicWall.
• If the point to point link to Site A goes down then the Site B network will access the Internet through the local Site B DSL line

Site A

• LAN IP is: 10.29.1.1
• WAN IP is : 72.35.91.2
• X5 Interface IP is: 10.33.1.2

Site B

• LAN IP is : 192.168.168.168
• WAN IP is: 12.12.12.12
• X5 Interface IP is: 10.33.1.1

RESOLUTION:

On Site B SonicWall

•   Create a route by navigating to Manage | Network | Routing. This is to introduce that the gateway for the Site B Network is another device.
  
  Source: LAN Subnets or Firewalled Subnets 
  Destination: Any 
  Service : Any  
  Gateway: 10.33.1.2  (X5 Interface IP of Site A since point to point connection is through X5 Interfaces of both devices) 
  Interface: X5
  Enable the option which says Disable route when the interface is disconnected
   

 On Site A SonicWall 

•  Create a route by navigating to Manage | Network | Routing. This is for the return traffic destined for Site B.
  
  Source: Any
  Destination: Site B Network (192.168.168.0/24)
  Service: Any 
  Gateway: 10.33.1.1 (X5 Interface IP for Site B) 
  Interface: X5
   
  
  
• Create a NAT Policy by navigating to Manage | Rules | NAT Policies. This is to allow the Site B traffic Internet access. 
  
  Original Source: Site B Network (192.168.168.0/24) 
  Translated Source: WAN Primary IP or X1 IP 
  Original Destination: Any 
  Translated Destination: Original
  Original Service: Any 
  Translated Service: Original
  Inbound Interface: Any 
  Outbound Interface: Any
   

Testing: Go to whatismyip.com on a computer behind Site B. It should return the WAN IP of site A.

Resolution for SonicOS 6.2 and Below

The below resolution is for customers using SonicOS 6.2 and earlier firmware. For firewalls that are generation 6 and newer we suggest to upgrade to the latest general release of SonicOS 6.5 firmware.

On Site B SonicWall

•  Create a route. This is to introduce that the gateway for the Site B Network is another device. 
  
  Source: LAN Subnets or Firewalled Subnets 
  Destination: Any 
  Service : Any 
  Gateway: 10.33.1.2  (X5 Interface IP of Site A since point to point connection is through X5 Interfaces of both devices) 
  Interface: X5 
  Enable the option which says Disable route when the interface is disconnected
   

On Site A SonicWall 

•  Create a route. This is for the return traffic destined for Site B.
  
  Source: Any
  Destination: Site B Network (192.168.168.0/24) 
  Service: Any 
  Gateway: 10.33.1.1 (X5 Interface IP for Site B)
  Interface: X5
   
  
  
• Create a NAT Policy. This is to allow the Site B traffic Internet access. 
  
  Original Source: Site B Network (192.168.168.0/24) 
  Translated Source: WAN Primary IP or X1 IP 
  Original Destination: Any 
  Translated Destination: Original
  Original Service: Any 
  Translated Service: Original
  Inbound Interface: Any 
  Outbound Interface: Any
   

Testing: Go to whatismyip.com on a computer behind Site B. It should return the WAN IP of site A.