- Products
- Network Security
Next Generation FirewallNext-generation firewall for SMB, Enterprise, and Government
Security ServicesComprehensive security for your network security solution
Network Security ManagerModern Security Management for today’s security landscape
- Advanced Threat Protection
Capture ATPMulti-engine advanced threat detection
Capture Security applianceAdvanced Threat Protection for modern threat landscape
- Access Security
Cloud Edge Secure AccessDeploy Zero-Trust Security in minutes
Secure Mobile AccessRemote, best-in-class, secure access
Wireless Access PointsEasy to manage, fast and secure Wi-FI
SwitchesHigh-speed network switching for business connectivity
- Email Security
Email SecurityProtect against today’s advanced email threats
- Cloud Security
Cloud App SecurityVisibility and security for Cloud Apps
Cloud Firewall (NSv)Next-generation firewall capabilities in the cloud
- Endpoint Security
Capture ClientStop advanced threats and rollback the damage caused by malware
Content Filtering ClientControl access to unwanted and unsecure web content
- Product Widgets
- Product Menu Right Image
- Network Security
- Solutions
- Solutions Widgets
- Solutions Image Widgets
- Solutions Widgets
- Partners
- Partner Widgets
- Partners Image Widgets
- Partner Widgets
- Support
- Support Widget
- Support Image Widgets
- Support Widget
- Products
- Network Security
- Next Generation FirewallNext-generation firewall for SMB, Enterprise, and Government
- Security ServicesComprehensive security for your network security solution
- Network Security ManagerModern Security Management for today’s security landscape
- Advanced Threat Protection
- Capture ATPMulti-engine advanced threat detection
- Capture Security applianceAdvanced Threat Protection for modern threat landscape
- Access Security
- Cloud Edge Secure AccessDeploy Zero-Trust Security in minutes
- Secure Mobile AccessRemote, best-in-class, secure access
- Wireless Access PointsEasy to manage, fast and secure Wi-FI
- SwitchesHigh-speed network switching for business connectivity
- Email Security
- Email SecurityProtect against today’s advanced email threats
- Cloud Security
- Cloud App SecurityVisibility and security for Cloud Apps
- Cloud Firewall (NSv)Next-generation firewall capabilities in the cloud
- Endpoint Security
- Capture ClientStop advanced threats and rollback the damage caused by malware
- Content Filtering ClientControl access to unwanted and unsecure web content
- Product Widgets
- Product Menu Right Image
- Network Security
- Solutions
- Solutions Widgets
- Solutions Image Widgets
- Solutions Widgets
- Partners
- Partner Widgets
- Partners Image Widgets
- Partner Widgets
- Support
- Support Widget
- Support Image Widgets
- Support Widget
Using Multiple DHCP Servers Behind SonicWall Firewall (UTM) Appliances
03/26/2020 
17 People found this article helpful
45,027 Views
Description
Using Multiple DHCP Servers Behind SonicWall Firewall (UTM) Appliances
Resolution
You generally should not set up multiple DHCP servers on the same network segment. The danger is that the two servers will conflict. By carefully following the two rules below, it is possible to run two DHCP servers (one being the DHCP server built into the SonicWall) on the same LAN segment for redundancy:
- There should never be any overlapping scopes for the two DHCP servers for any dynamic IP pool. (This prevents a lease for the same IP from being given to multiple machines)
- Overlapping scopes are permitted for the two DHCP servers only for IP addresses that are statically mapped by MAC address. Even if a lease is handed out by both of the servers for the client at that MAC address, it's a no harm, no foul event because only one client, at that MAC address, gets the lease for the IP. Eventually, the extra lease will expire, and the client will then request, and get, a renewed lease from only one of the servers.
If your LAN is divided by a router into multiple IP subnets, then you can have multiple DHCP servers, one for each segment, without concern for the rules listed above. Each segment should, normally, have no more than a single DHCP server. In such a configuration it is important that the router does not pass DHCP broadcasts. If you are supporting multiple subnets, consider using a single Linux or Windows based external DHCP server for all of them. The SonicWall's DHCP server cannot support this configuration.
Related Articles
- All associated wildcard FQDN IP addresses do not display in the web browser
- How to Re-Install The Junk Store
- SonicWall NSv Series FAQ
Categories
- Firewalls > TZ Series
- Firewalls > SonicWall SuperMassive E10000 Series
- Firewalls > SonicWall SuperMassive 9000 Series
- Firewalls > SonicWall NSA Series
YES
NO