Hey folks, I am trying to set up a Netgate 2100 to provide DHCP to a US-8-60W on VLAN200. I have LAN port 1 configured on the 2100 to provide VLAN200 tagged, and the US-8-60W is already adopted into my Unifi controller and is set to have VLAN200 as its management network. Other devices (namely a Minisforum mini-pc running Kali), when configured to DHCP over VLAN200 and plugged into the same port, work as expected and get an IP on the subnet that the DHCP server running on VLAN200 provides. However, the US-8-60W never does get an address.
To do some debugging around this, I have set port 3 on the US-8-60W to mirror port 1 on that switch, so I can use Wireshark to do packet captures of the DHCP traffic that the switch sees.
The weird thing is that the switch sends out DISCOVER packets, and at least I see on the mirror port that it gets back the OFFER from the 2100, but it never does a REQUEST to get an address from the server.
I also have a Netgate 6100 with the same configuration (though a different subnet on VLAN200), which, when I plug in the US-8-60W, works fine. So, there’s some weird compatibility problem between the 2100 and the US-8-60W specifically. I have even done pcaps of plugging the same switch into both networks (I never have plugged this switch directly into the 6100 - just into other switching gear that is uplinked to it), and I can’t spot any obvious differences in the DISCOVER/OFFER packets received from one network to the other other than the expected MAC/IP/Subnet/Domain stuff one would expect to differ between the networks.
Again - other clients seem to work on the same port of the 2100. The US-8-60W seems to work fine on a different router. I have a second US-8-60W with the same configuration, and they exhibit the same behavior, so it’s not just a specific device issue.
Any ideas here? This is super weird to me. Everything seems to work apart, but when I try to put the pieces together, it doesn’t. Super frustrating.
I have also been trying to work through this on the Netgate forums (see the thread for more details if you’re interested), but I’m not getting the answers I seek thus far.
Thanks in advance!