Multichassis Etherchannel – Cat 6500 VSS

[mile.ljepojevic]

Hi,

I configured Etherchannel between 3 ports on server and on Cat 6500 VSS, two ports on one physical chassis, and one port on another.

If I look at etherchannel status, I see no errors.

I used port-channel load-balance src-mac as LB algorithm, since most of the servers accessing that server are on the same LAN, so their MAC addresses should be visible to the switch.

As a guide-line I used this document:

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a008089a821.shtml#guidelines

The problem is that LB is not working! At all!!!

We tested with copying multiple files from/to that server, to/from multiple servers on the same LAN segment, and we always see just one NIC used for TX traffic (NIC 1), and NIC 3 is used for RX traffic (practically, switch is forwarding all traffic through one interface). And we hit 92% of utilization on the link not even then next flow didn’t go through other etherchannel links.

Is there any issue with our setup?

Thanks,

Mile

[manish arora]

what's the server on the other side ? Linux , windows etc . I configured server bonding on CentOS few days back ( using a totally different switch -- no cisco ) , it wasn't working and was showing the same symtoms. I ended up using LACP on the switch side with src/dest mac hashing and bond mode 802.3ad on the Centos side. It was only then it started load balancing traffic across four links in tha Bond.

Manish

[mile.ljepojevic]

It is Windows 200x servers... We tried that on 2 different HP servers. But it's windows either way.

We also tried LACP and no negotiations, the results were the same.

[manish arora]

Hi Mile,

No words ... just Links :-

http://support.microsoft.com/kb/278431

http://social.technet.microsoft.com/Forums/en-US/winserverDS/thread/f5dea401-5a3b-4ddb-8bb8-8d2b2e2db55b

Manish