Portchannel lacp connected to non etherchannel port

[hasinmeir]

Hello

we have a working setup with 2 x Cisco 3750 stack that connected to 2 x Cisco 6500 standalone HSRP.

There are 2 ports from the stack switches that connected to the 6500. gi1/0/5 and gi2/0/5 on the 3750 side.

both ports on the 3750 are configure to be in “port-channel 3 mode active” but the ports on the 6500 side are configured to be regular ports and not ether channel.

So, we have LACP on one side and regular ports on the second side. 

In general, everything is working fine. But, we have some packet loss issues in the network and we thought maybe inconsistent ether channel can cause such strange behavior?. it can cause drops on the interfaces?

thanks a lot.

[Masoud Pourshabanian]

Hello,

I wonder how it works. If you configure etherchannel only on one side, ether channel is not going to be created.

What is the status of ether channel?

Show interface port-channel 3.

Have you configured Spanning tree in you network. Configure spanning tree and remove that etherchannel. Just Imagine you have only one 3750 with two ports connected to 6500-1 and 6500-2.

Masoud

[jbowman1985]

To follow what Ganesh wrote:

Use "show eth sum" command to see the status of the etherchannel interface.  Chances are, the etherchannel interface is in "I" which is stand-alone.  The individual ports, gi1/0/5 and gi2/0/5 on the 3750 are probably up/up as well as the interfaces on the 6500.

Are these links layer 2 or layer 3?  If they are layer 2 links, then one of the ports will be in a blocking state because of spanning-tree.

If your link between the 3750 and 6500 has high utilization this could be the cause of your packet loss.

[Ganesh Hariharan]

Hello ,

Single port from 6500 series switches to stack switches which are in portchannel, I dont think so your stack is having portchannel up.

what is the output of show etherchannel summry in 3750

If the ports are in (I)ndividual port - that means that the opposite device is not speaking LACP to it so it cannot negotiate about even becoming an EtherChannel member link.

Hope it Helps..

-GI