I have this very weird problem and I am at a loss where to even start looking for the cause. I have a pfsense acting as router and doing VLANS and dhcp and so on, a CRS326 and two CAP AX. The CAP AX are chained, meaning CAP 1 is connected to the switch, CAP 2 is connected to CAP1. After CAP 2, I have a dualboot desktop machine. The ethernet port that this machine is connected to on the CAP 2 is configured as a VLAN access port.

When I boot windows, it gets an ip via dhcp just fine (in the correct VLAN and all). But when I boot linux, I can see the DHCPDISCOVERs and DHCPOFFERs on the dhcpserver in the correct VLAN, but never a DHCPREQUEST or DHCPACK. The ip part on the client side is configured properly and there is no firewall intervening. The only thing client-wise I am not so sure about is the VLAN, but as far as I understand, the client never sees anything VLAN-specific, since the ethernet port it is connected to is an access port.

I have no idea where to start looking or how to diagnose this. I tried tracking the DHCPOFFER through CAP 1 and CAP 2, with Torch but it is hard to stay on top of things with this tool. I am thankful for any ideas on what is going on here or what to dig into.

The ethernet port that this machine is connected to on the CAP 2 is configured as a VLAN access port.

Are you sure that ether port on cAP is properly access port? The big difference between windows (most ether drivers) and linux is that linux properly works wiith VLAN tags while windows (often) simply ignores them ...

Are you sure that ether port on cAP is properly access port? The big difference between windows (most ether drivers) and linux is that linux properly works wiith VLAN tags while windows (often) simply ignores them ...

That was it. In /interface bridge vlan, I didn't have my ethernet port set as untagged. Thank you very much!

That was it. In /interface bridge vlan, I didn't have my ethernet port set as untagged. Thank you very much!

If a port of bridge has pvid set, then it's automatically added as untagged port to appropriate VLAN in the section you mentioned. But this doesn't work if the same port is explicitly configured already (either tagged or untagged). This automagic works reliably, so it's advisable to skip explicit addition of access ports to VLAN (same goes for untagged/native VLAN for hybrid ports).

If a port of bridge has pvid set, then it's automatically added as untagged port to appropriate VLAN in the section you mentioned. But this doesn't work if the same port is explicitly configured already (either tagged or untagged). This automagic works reliably, so it's advisable to skip explicit addition of access ports to VLAN (same goes for untagged/native VLAN for hybrid ports).

I KNEW I read somewhere that untagged ports don't need to be set explicitely. I have now corrected it on my cAP. On my switch, which has a lot more access ports, I already had it set up the correct way. Thanks!