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Question about STP and multiple VLANs

shikamarunara
Level 4
Level 4

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?

-Shikamaru

2 Accepted Solutions

Accepted Solutions

etamminga
Spotlight
Spotlight

Do you have any ports up in that VLAN?

Regards,

Erik Tamminga

View solution in original post

Yup,

You have to have at least 1 active interface/port in a VLAN for it to come up

View solution in original post

4 Replies 4

etamminga
Spotlight
Spotlight

Do you have any ports up in that VLAN?

Regards,

Erik Tamminga

Yup,

You have to have at least 1 active interface/port in a VLAN for it to come up

Misconfigured trunk port. Looks good now. Thanks.

-Shikamaru

Shikamaru,

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.

HTH

Sundar

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