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CSM accumulating rxOversizedPkts, FrameTooLongs on 6509

We are benchmarking a tiered environment with 16 Loadrunner clients running on AIX talking to two http/apache server farms (16 servers in two subnets) managed by dual CSMs in a 6509 running in hybrid mode. Everything (clients, servers, CSM) is setup with Jumbo frames enabled. The 6509 is running supervisor 1 with MSFC (Cat OS supk8.7-6.5, msfc 12.1(19)E1) Part of our testing is to drive the Loadrunner clients as hard as we can to send web pages load-balanced via the CSMs to the http servers. When sending a load, the client runs 80-100 cpu busy, and I'm seeing an accumulation of rxOversizedPkts, FrameTooLongs, on the csm ports on the switch, and connections failed and Overflow errors on the MSCF when issuing a sh module x csm all stats. Can anyone explain if these are errors that could affect the performance of the CSM and slow down our timings, ability to process the submitted load?

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Re: CSM accumulating rxOversizedPkts, FrameTooLongs on 6509

What version of CSM code are you running?

Here's a snippet from CSM 3.2(1) Release Notes:

The support of Jumbo Frames has been added to the CSM in version 3.2(1) allowing for support of frames of up to 9k bytes for Layer 4 load balancing.

Here's a snippet from CSM 3.1(6) Release Notes:

* CSCea78134

In previous releases, the CSM was unable to forward jumbo frames. In CSM software release 3.1(5), a jumbo frame up to 9,216 bytes can be forwarded by the CSM to the peer bridge VLAN. A jumbo frame can also be forwarded to it destination if it matched an existing Layer 4 connection. In a switch running both Cisco IOS software and the Catalyst operating system, you must enable jumbo frame for the CSM internal ports.

Hope this helps.

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Re: CSM accumulating rxOversizedPkts, FrameTooLongs on 6509

Thanks for your information. Just some follow-on questions. We have jumbo enabled at the Cat OS level by issuing the set port jumbo command. Is there another way to enable jumbo frames for the CSM internal ports? Is there a setting that has to be done at the MSFC IOS level like setting mtu values. I did a search on the CSM configuration guide and it does not show the commands for enabling jumbo frames. Our CSMs are running 3.2(1).

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