DHCP Server for multiple vlan

[yuiop788]

Hi everyone,

Here's my network topology.
https://drive.google.com/file/d/12gVpeacvfyUqJH7GzuDUhUiclIdMuwtP/view?usp=sharing

I don't know OPNsense have this function or not. :-\
I need OPNsense to be a DHCP server, offering IPs for multiple vlan.
But I'm not using Trunk port to do this.
Core switch will be the DHCP relay agent, once VLAN 10 and 20 client request IP,
Core switch will relay them to OPNsense through VLAN 100,
and OPNsense offer different network subnet ip based on their vlan.

I do some LAB on Mikrotik, and it works fine. ;D
But I don't know how to configure this function on OPNsense.

Please help me to figure it out, thanks~~~
:)

[bartjsmit]

Services, DHCPv4, select the interface of the network on which you want to enable DHCP, tick enable and fill in the subnet parameters.

Don't use DHCPv6, use RADVD instead - Services, Router Advertisements

Bart...

[yuiop788]

Hi bartjsmit,

But OPNsense doesn't allow this action, it shows "The gateway address 172.16.10.254 does not lie within the chosen interface's subnet."

[bartjsmit]

The OPNsense IP address in each VLAN should be the default gateway. Make sure your interface, subnet and mask all match the DHCP scope.

[Patrick M. Hausen]

@bartjsmit From the topology map it is evident they want a DHCP server serving multiple subnets while connected to only one. There are probably DHCP relays configured on that core switch.

@yuiop788 I do not know if ISC-DHCP or OPNsense support that at all, sorry.