We have two buildings connected through a fibre link.
One building has a L3 switch, which has been configured with VLANs for each classroom and one VLAN for the server room. We can connect between the VLANs without problem.
The second building has been configured with VLANs for each of its classrooms and another for its server room. Using router-on-a-stick, these VLANs can interconnect.
The fibre connection between the server rooms has been configured to carry all the VLANs tagged using 802.1q.
All VLANs are unique.
However, we cannot get connection between a VLAN in building 1 and another VLAN in building 2.
I suspect that this is because there is no port in the Building 1 L3 switch that is the untagged (default gateway) for VLANs in Building 2 and, similarly, the L2 switch in Building 2 has no untagged (default gateway) port for VLANs in Building 1.
Is it necessary for me to configure the router-on-a-stick in Building 2 to perform all the inter-VLAN routing? I'd prefer not to do this as most of the traffic will remain within the discreet buildings but we do require occasional traffic between the buildings.
I'd appreciate any suggestions regarding configuring inter-VLAN routing retaining the L3 switch inter-VLAN routing in Building 1 and the router-on-a-stick inter-VLAN routing in Building 2, if practical.