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New Member

Changing a VLAN STP priority

We have three 6509's basically connected in a chain. The first two 6509's share the responsibility of being the root bridges for all the VLAN's. The first two also run HSRP. Switch 1 is primary root for odd numbered VLAN's and secondary for even's. Vice versa for Switch 2.

My problem is that several VLAN's were added recently, but were not given any sort of priority. Consequently, the third switch has become the root for these. If I add the new VLAN's to the proper STP roots, am I going to cause an outage on all VLAN's while the spanning tree is recomputed or just the new ones?

The commands I use are:

spanning-tree vlan 2,4,6 priority 8192

spanning-tree vlan 3,5,7 priority 16384

1 ACCEPTED SOLUTION

Accepted Solutions
Purple

Re: Changing a VLAN STP priority

Hi,

Given that you are using PVST(+) only the affected VLANs will experience an outage.

Paresh

2 REPLIES
Purple

Re: Changing a VLAN STP priority

Hi,

Given that you are using PVST(+) only the affected VLANs will experience an outage.

Paresh

New Member

Re: Changing a VLAN STP priority

Thank you for the reply Paresh. You've set my mind at ease.

Hugh

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