Using a DHCP relay agent with a SonicWALL

MikeMurray

Hi everyone!

I have an existing network with multiple VLANs that are routed by a Cisco L3 switch (10.6.0.x/24, 10.6.2.x/24 etc). The Cisco handles all routing for the network and its default gateway is the SonicWALL X0 interface which is connected by a point-to-point L3 connection (10.6.50.x/30). If we wanted to use the SonicWALL as the DHCP server instead of the Cisco switch, can we enable the DHCP relay agent on the Cisco and forward DHCP requests to the SonicWALL? The SonicWALL has no interfaces on any of the VLANs and there doesn't seem to be a way to assign a specific DHCP scope to a specific VLAN without the SonicWALL having an interface on the VLAN in question.

Thanks for any guidance you can provide!

Mike

BWC

@MikeMurray I guess you answered your own question already. Because the SNWL does not know about the VLAN Interfaces it cannot assign IP addresses via DHCP to it. You can create the scopes and they'll end up with no Interface Assignment (n/a).

The DHCP Server on the SNWL is pretty basic and cannot work on conditions etc.

Because your subnets are routed through the Cisco you cannot assign the VLANs to the SNWL, that would break your routing. Maybe if you create custom Routes for each VLAN with a better priority, but this is not really handy.

You don't have any other option for providing DHCP?

--Michael@BWC