DHCP Relay on specific VLANs only?

Switch: cnMatrix EX2028-P
WAPs: XV2-2


We have multiple VLANs within our environment. The EX2028 is configured as our “core” and has multiple L3 interfaces. We have enabled DHCP Relay via the EX2028-P GUI to point to our external DHCP server (Windows Server 2019). Inter VLAN routing is working and the clients are acquiring DHCP leases as expected.

Now for the problem. We want to introduce a second external DHCP server (firewall/web filter) for our Guest Wi-Fi. We have declared a new guest VLAN on our EX2028-P but without creating a L3 interface (in order to isolate this network). The new external DHCP server is tagged with the same VLAN ID as our new Guest VLAN. I believe the DHCP relay setting (enabled earlier) is relaying all DHCP requests to the original Server 2019, rather the new external DHCP that’s located within the same VLANs.

In short - Is it possible to set IP helpers/DHCP-Relay on selected VLAN interfaces, rather than applying to all VLANs (including those without a L3 interface)?

I’ve done this successfully with Cisco, Ruckus, Brocade and Meraki, but I can’t find a way of doing it here with Cambium.

Please help



Hi Tom,

cnMatrix does not support association of DHCP server to selected VLAN interfaces. This feature is currently planned for later this year.


On the Cambium AP, you can have a DHCP Relay per VLAN as per this screenshot.