How to troubleshoot C4k_L3HWFORWARDING Messages from Cat4500

[lo.mueller]

Hi there,

I got following messages from cat4500 in cyclic intervals

- WS-C4506 with Sup IV

- IOS: 12.2(46)SG

C4K_L3HWFORWARDING-3-

* MASKTABLECONSISTENCYCHECKFAILED

* FWDCAMCONSISTENCYCHECKFAILED

Searching thru cisco.com it is stated that TAC should be contacted.

Before doing that I want to ask the switching-experts how to further troubleshoot the problem and what is the real source of the problem.

Thanks for any feedback.

Lothar

[Giuseppe Larosa]

Hello Lothar,

these are consistency checks performed on the CEF tables.

The tests failed and this can be a sign that tables are corrupted.

There is a chance that some specific flows are not forwarded correctly by your device.

Or simply the tests can fail for some problem on the test execution caused by a bug.

I would schedule a maintanance window for reloading the device and then you can see if the messages disappear.

If they come back it is likely an hardware problem.

Hope to help

Giuseppe

[lo.mueller]

Hi Giuseppe,

thanks for your feedback.

Do you know whether there are any test-commands available checking these consistency checks, or is this simply something going on behind the scenes?

Did you ever had this issues?

Thanks

Lothar

[Giuseppe Larosa]

Hello Lothar,

I haven't had the same issue but there had been threads in which the problem was a test reporting the failure of a linecard of type SIP and this was a false failure.

In your case being the CEF table used to forward traffic unless you see "holes" for some flows you should be fine

I tried to search for a bug unsuccessfully.

Hope to help

Giuseppe