BPDU format on access port?

[stefan.tabell]

Hi,

On a port configured as an access port, on a switch running rapid-pvst, what information is sent in the BPDU on this port? Is it only STP information related to the one VLAN, or also information for other VLANs?

The background is that I have two /16 networks that needs to be interconnected (core switch to core switch), but each network should be it's own in terms of STP etc. It could be acceptable to have one VLAN (transit VLAN) that is spanning over both core switches as long as the shared spanning tree is only for this VLAN.

So will an access port, example VLAN 10, only send BPDU for this VLAN or also for all other VLANs? 

Hope this made sense, thank you!

[Reza Sharifi · Accepted solution]

Hi,

If the port between the switches will be configured with one vlan, than there is no other info passing through that link. You can use a transit vlan (configured as access port) to connect the 2 cores together or you can simply use a routed link (no vlans) with a /30 IP between the 2 cores.

HTH

[stefan.tabell]

Thank you for your answer. 

A routed link was in consideration, but wouldn't you lose your QoS tagging then? The QoS tag needs to stay until when the frames hits the WAN router.