2 root bridge

[Dan_17717]

Hi All,

For some reason, I'm getting 2 root bridge in my network.  The current root bridge is the 3560X and is also the vtp server.  Recently, we purchased a few more switches N3K-C3064PQ-10GE and 2960x-48LPD-L.  The 2960x-48LPD-L is also a vtp client.  When connected to the N3K-C3064PQ-10GE, it becomes the root bridge.  It's not the bridge priority because I set the 3560x with the lower priority number to become the root bridge.  Also, if I connect the 2960x-48LP-L to another 2960s vtp client, it doesn't become the root bridge.  It only becomes the root bridge if I connect it to the N3K switch.  Can someone tell me why this is happening and can I leave it as a root bridge without it affecting the network?

[Reza Sharifi]

Hi,

It maybe because you have 2 different segments, with N3K-C3064PQ-10GE running a different STP protocol than the catalyst 3560x and 2960x switches. So, if you want to run the same STP protocol across all switches, check the Nexus and make sure it is running the same STP as the Catalyst.

HTH

[Dan_17717]

The Nexus switches are seeing the 3560x as the root bridge so I'm guessing it's using the same STP protocol.  Is it ok to leave the 2960x-48lpd-l as the root bridge as well since there are no redudant links?  Thanks.

[Dan_17717 · Accepted solution]

Nevermind, I got it working.  It was a mistake on my part for not including all the VLANs in the N3K.  Since the 2960X was a VTP client, it had all the VLANs propagated over.  When it connected to the N3K, only the VLANs that was not in the N3K was showing up as root bridge for the 2960x.  So I just had to put the VLANs in the N3K for the root bridge to be the 3560x.  I should've looked at it more clearly.  Thank for the suggestion though.

[Reza Sharifi]

Glad to know it is all working for you.

Good Luck!