GLBP Output Question...

Unanswered Question
Nov 16th, 2007


I have one 6500 at site "a" connected to two 4948's and those two 4948's are connected via fiber to two more 4948's that are connected to another 6500 at site "b". The two connections between the 4948's are at layer two. I have GLBP up and I see the vlans as up. I have set priority for some of the vlans on site "a" and the others to be primary at site "b" and it seems to be working but when I run a "sh glbp brief" on each 6500 I guess I expected the output to be the same but just reversed (for each 6500.

Can you please explain to me why the output is not the same (meaning not just reversed?).

I would have expected it to be presented that way and am not sure why it isn't.


Hopefully I have given enough information. :)

I have this problem too.
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m_zabetian Fri, 11/16/2007 - 10:10

Don't worry you don't have any problem

Everything looks good.

Let talk about Vlan 16 first line

Switch B is secondary because of priority so it is standby Is your default gateway Is your Active interface (GLBP dose load balancing so does not really matter?)

Local (switch B) is standby

william.briere Fri, 11/16/2007 - 12:15


Using the description I have given where the two 4948's on each site are connected via fiber at layer two to the other two 4948's (Wow that's a mouth full)... Should I expect to see any spanning-tree issues?

It was mentioned to me that I would have possible spanning-tree issues but I didn't see anything amiss...

m_zabetian Fri, 11/16/2007 - 15:03

I need to see you configuration for GLBP and spanning tree but GLBP cannot create Spanning tree problem. If you are configure it correctly. Base on your show glbp br you GLBP should be healthy. Check sh logg to see, they change active and passive a lot if they do then maybe you have issue. some useful commands are debug glbp error and debug glbp event

For spanning tree you should control your spanning tree and you are the one chose your primary root.


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