Transparent Mode Trunking

yurixewx7 · ‎10-30-2008

I have a question regarding the way trunks operate in an environment where all the switches are in transparent mode.

Image the following scenario.

You have 4 switches trunked in the following configuration. A connects to B -> Connects to C -> connects to D

SwitchA---SwitchB---SwitchC---SwitchD

If Switch A and D have vlans 10, 11, and 12 configured, but B and C do not have these vlans configured. Will the traffic for these vlans be able to get from Switch A to D? Or would the switches between them, B and C need these vlans configured on them?

Jon Marshall · ‎10-30-2008

Yuri

If the switch is in VTP transparent mode then it will forward VTP advertisements across it's trunk links even though it doesn't update it's own vlan database.

However you are talking about transmitting vlan traffic. For your scenario to work the vlans need to be configured on all switches or the traffic from the vlans on Switch A will not get to the vlans on Switch D.

Jon