hi all
in this simple topology
SW1 ----------- SW2 ------------ SW3
SW1 = VTP server, SW2 and SW3 = VTP client
SW3 = STP root for all Vlans
everything was working fine,
I changed SW2 to be in transparent mode, when I made some changes in SW1, the updates ware not sent through SW2 to SW3.
I chacked show interface trunk on SW2
Port Vlans in spanning tree forwarding state and not pruned
Fa0/13 7,43,58,67,79,146
Fa0/14 7,43,58,67,79,146
Fa0/15 7,43,58,67,79,146
Fa0/16 7,43,58,67,79,146
Fa0/17 7,43,58,67,79,146
Fa0/18 7,43,58,67,79,146
Fa0/19 7,43,58,67,79,146
Fa0/20 none
Fa0/21 none
as you see, it is filtering Vlan 1 !! (which I did not understand why this is by default with transparent mode?)
I had to change SW2 to be Root Bridge, then Vlan 1 has been added, and everything returned to work fine.
show interface trunk on SW2
Port Vlans in spanning tree forwarding state and not pruned
Fa0/13 1,7,43,58,67,79,146
Fa0/14 1,7,43,58,67,79,146
Fa0/15 1,7,43,58,67,79,146
Fa0/16 1,7,43,58,67,79,146
Fa0/17 1,7,43,58,67,79,146
Fa0/18 1,7,43,58,67,79,146
Fa0/19 1,7,43,58,67,79,146
Fa0/20 1
Fa0/21 1