Sorry, I mean that when I realized I didn’t have mainBridge marked for tagged VLAN2 egress, I initially tried marking mainBridge for both tagged VLAN2 egress AND tagged VLAN1 egress.
That didn’t work either, and I’m guessing that by marking mainBridge tagged for VLAN1 egress, the mainBridge switch must be handing the mainBridge interface tagged packets and the mainBridge interface must not be stripping the tags causing the DHCP server not to see them.
I.E., with mainBridge tagged for VLAN1 and ether 4 set for untagged VLAN1 and with PVID 1, this is what I think must be going on:
DHCP Server → (untagged) → mainBridge interface → (tagged VLAN1) → mainBridge switch → (tagged VLAN1) → ether4 → (untagged) → client
client → (untagged) → ether4 → (tagged VLAN1) → (mainBridge switch) → (tagged VLAN1) → mainBridge intreface → (tagged VLAN1 ?) → DHCP Server doesn’t get the packet
This surprised me because the mainBridge interface is set to PVID 1, so I expected VLAN1 tags to be stripped on ingress, but things were clearly not working this way.