6509 Cat OS and VM Trunking

[sestonenppd]

We have a VM server farm that we just converted from access port connections to trunked connections into our 6509 (we'll call it C).  C is connected via trunks to our 2 core switches A and B by gig fiber.  Whenever one of the VM servers is rebooted, or a trunk port (all are copper gig) is disconnected then reconnected, for some reason, A and B prune all the VLANs on their trunks to C and data connection is lost for a long enough period of time that our phones cannot register to the CUCM (connected to C) and some other data hits have now been reported.  Anyone else run into this?

Cisco 6509 Sup 2GE

CAT OS 8.2(2)

ESXi4.1

[Matthew Blanshard]

What are your VTP modes on the 3 switches? 

-Matt

[sestonenppd]

They are all VTP ver 2, with A and B servers and C client.

[glen.grant]

  Can't say I have heard that  .  Maybe something going on with spanning tree, make sure all vm servers have portfast turned on ..

[sestonenppd]

I thought, or our policy is, that portfast should be disabled on trunk ports.

[glen.grant]

  On trunk ports to network devices should have portfast turned off  .  To servers it's ok as long as the servers are not running spanning tree . In IOS there is even a command spanning-tree portfast trunk that should be used for servers.   You can google vmware and spanning tree for more information . 

[sestonenppd]

This seems to have helped. At least we don't lose data or phone connections but we still have the trunk VLAN pruning.

Thanks for the help.