Hello everybody!
I have a problem with forwarding management vlan. We have two buldings connected with 1000-BaseLX. On one side there is switch Allied Telesis AT-9000, and on the other side we have Cisco SG200-26 26-port Gigabit Smart Switch.
This is the only connection between the buildings. Ports are configured as trunks with many tagged vlans and one untagged which is both default and administrative vlan for us. Every tagged vlan is responding correctly and working between the buildings, but via this untagged vlan, both sides doesn't see each other.
RSTP is forwarding everything. There is no any other untagged vlan.
We do not know the exact time of connection loss. It could be after upgrading firmware on Cisco switch. Unfortunately noone checked it at the beginning.
Everything seems like connection between the buildings is incorrectly configured. Anyone can have some idea what can I check more for solving this problem?
Regards,
Bartek.
