Cisco 6509-E PAgP issue

[Alessandro03]

Hi all,

i have a strange issue regarding two 6509-E that form my core network.

Actually there is a Etherchannel with PAgP protocol between them, without VSS.

The TenGig ports of the Standby Hot supervisor of the switch A are connected to the TenGig ports of the Active supervisor of the switch B.

All is working fine, but when i try to add another TenGig in the Etherchannel (let's say a port of the other supervisor) i lose connection to some devices in the network. E.G. i can ping them but i can't access via 443.

The only way to solve the problem is to disable the third link.

The etherchannel works fine only if i have the TenGig ports of a supervisor connected with the TenGig ports of the other supervisor's switch. No matter if they are Active or Standby.

Did anyone experienced this issue?

[Reza Sharifi]

Hi,

What model Sup do you have? Also, do both switches have dual Sups for a total of 4 Sups?

Have you tried adding 2 more ports to the Portchannel instead of just one and test?

HTH

[Alessandro03]

Hi, the model of the SUP is Supervisor Engine 720 10GE (VS-S720-10G) for both switches.
Both switches have dual SUP

I already tried to add 2 more ports and i still have the problem.

Thanks
Alessandro