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Odd routing (?) issue

Posted on 2008-06-16
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Last Modified: 2010-04-12
I've had a couple of machines (all in the same physical area) just lose their network connectivity.  They can ping their gateway, but nothing beyond it.  It appears as though the 'echo request' is actually getting off their subnet, but the 'echo replies' aren't getting back to them.  Similar problem with the VOIP (separate voice vlan) -- you can hear them, but they can't hear you.  If I statically assign a different IP in the same subnet, it works fine.  I've also tried to change their VLAN assignment, still have the problems.  So far it's happened to almost everyone in that area, at different times.

They're connected to a Cisco 3550, IOS 12.1.  That is physically connected to another 3550 that's acting as the router (there's actually 2 core switches configured in a failover mode)

Anyone seen this before?  Or have any troubleshooting steps or debug ideas?
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Question by:wildbluesky
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by:wildbluesky
ID: 21796674
Did a little more troubleshooting -

There's an ip address that requires routing that I can't ping (it is pingable from other devices on same subnet)  I changed my default gateway to be the failover switch and now I can ping it.  Change my gateway to point directly to the 'primary' and it stops working again.  So it's def something with that primary switch's routing ability.  Being a core switch, I don't really want to bounce it if I can help it.... ideas?
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wildbluesky earned 0 total points
ID: 21806002
While I'm still not sure why all of this happened, I added a priority statement to the standby sections of the backup switch's config making it the active for everyone - that has solved my problem.
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