Question about STP and multiple VLANs

Answered Question
Feb 8th, 2007

I've configured my core switch to be the primary root for 3 vlans. On 2 vlans, everything seems to be showing up fine, on a third vlan I have "Spanning tree instance(s) for vlan X does not exist." Does someone know what this could be from?


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Correct Answer
etamminga Thu, 02/08/2007 - 10:28

Do you have any ports up in that VLAN?


Erik Tamminga

sundar.palaniappan Thu, 02/08/2007 - 11:35


In addition to what the previous posters stated I would add if you have a trunk in which a VLAN is active that would cause the STP instance for that VLAN to be enabled as well. Since you already had active trunks, I assume your trunk must have been filtering/blocking the VLAN in question and that probably was the cause of the problem.




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