DHCP won't assign IP on unttaged Port

[y0ng]

Hi everyone,

This is my first post after extensively reading about setting up my OPNsense. I'm encountering an issue that I haven't been able to resolve. Let me describe my setup:

I have an OPNsense VM running as my router/firewall on Proxmox, using a 4-port Intel NIC:

Port 1: WAN
Port 2: Management interface (no VLAN)
Ports 3 and 4: Configured as a LAG carrying several VLANs

The OPNsense is connected to a 16-port TP-Link Omada SG2016P switch. My printer is connected to port 12 on the switch. Port 12 is set to untagged with a PVID of 90, which is the VLAN from which the printer should receive an IP address. All other VLANs are not available on that port.

I have configured the printer's MAC address in the corresponding VLAN's DHCP settings to get a lease with a specific IP address, but the printer does not receive an IP at all. When I set VLAN 90 to accept unknown devices, it still doesn't get an IP. When I manually set the IP on the printer, there is no connection. My linux-laptop on the other hand gets the preconfigured IP assigned on that port.

It seems like I might be missing something in the configuration. What additional information do you need to help diagnose the issue?

Thanks for reading!

[Patrick M. Hausen]

Use "tcpdump -n -i vlan90 port bootpc" to observe DHCP requests. Replace "vlan90" with the OS name of the interface. You can find that in Interfaces > Overview or with "ifconfig" on the shell.

If you do not see any DHCP requests from your printer than it's something about your switch or the tagged port connecting OPNsense to the switch.

If you do see requests but no replies, the problem is probably on the OPNsense side.