VLAN 1 - PVST problem

[ALBA.]

Hi friends,

My company is currently using a ring topology but I have seen that 2 links are in the blokking state. At one link, all VLANs are blocked except VLAN 1. At the other link, only VLAN 1 is in the blokking state. Ideally all vlan's should be blocked on one link instead of on 2 links.   

Does somebody have experience with this problem?

Many thanks,

ALBA.

[Georg Pauwen]

Hello,

what is/are the root switch(es) for your VLANs ?

[ALBA.]

Hello my friend,

I hope this can help you.

Greetings,

ALBA. 

[rasmus.elmholt]

Hi,

Could you do a "show span vlan 1" and "show span vlan xx" where vlan xx is one of the other active VLANs you have in the setup.
And do both commands on you root primary and secondary?

[ALBA.]

You can find the commands in the document. 

Thanks for helping me!

[rasmus.elmholt]

As you can see in the command output you gave us the root bridge is using the default BID/priority on VLAN, but has been tuned for VLAN 102.

show span vlan 1 shows the "real" root bridge to have a priority of 1 but the bridge you want to be the root bridge is configured for the default priority of 32769.

Find the "real" root bridge for VLAN 1, change the priority to the default, and configure the bridge you want to be the root bridge with a priority of 4096 for VLAN 1.