7200 VXR problems with IMA

[MatJuiceB]

At work I have a 7200 VXR that has an IMA board on it that we use for ATM circuits. Now for what appears to be no apparent reason (no changes have been made). The router is dropping ATM lines, dropping as in not passing traffic but showing the line is up. So far the only solution I've read or seen is to shut / no shut the lines. But that only keeps them up for a very short time.

Using the debug atm events / errors doesn't show me any other then me turning off the line and turning it back on.

Does any one have any tips or ideas for what I could do to see whats going on, I've been told that there is a memory leak with this type of board but no one knows how to show evidence of this.

[smahbub]

Yes. this problem might be due to a memory leak issue. Check if the router ran out of processor memory and CEF was disabled.

[MatJuiceB]

CEF is enabled, should I turn it off? Cause when I do the CPU Load incresses alot.

I also have this:

show controller atm 3/0

rx_no_vcd=301

Alot of these no vcd's come in. The cpu and the memory seem to be fine, if it wasnt I'd think I'd see it happen to more than one circuit, but it seems to only attack one at a time.

[mbahardeen]

I was wondering if this issue ever got resolved. We are having this wierd isolated problem as well and havent been able to determine the cause of the problem. Any help is much apprecaited

[ahmed-hussein]

Hello,

There's an action plan that may help solving this issue

Action Plan

Intrusive ptt checking

If LCV (Line Code Violations) and PCV (Path Code Violations) increase , Upgrade IOS to 12.3(16) as recommended by both cisco

c7200-is-mz.123-16.bin and c7200-is-mz.123-16.bin

Min. Memory 128 (MB)

Min. Flash 32 (MB)

c7200-is-mz.123-16.bin

Min. Memory 96 (MB)

Min. Flash 32 (MB)

If the IOS upgrade will not help we need to apply the cabling work around Changing the RJ45 cable to

1)RJ45socket --120ohm balun ---- 75ohm ---- balun 120ohm-----RJ45socket

or 2) shielded RJ45 cable

And then eventually in case all of the mentioned steps will not help we will need to upgrade VWIC to VWIC2 card

Symptom:

Any Modular Access Routers with a VWIC-2MFT-T1 or VWIC-1MFT-T1 has problem with Line Code Violations (LCV)

and Path Code Violations (PCV) even when the circuit has been tested clean.

the bug is fixed in 12.3(16), 12.4(4)T, 12.4(3), 12.4(3.3), 12.4(4)T

VWIC modules can experience numerous Line Code Violations.

This is seen in the show controller output for the relevant E1/T1 interface.

Workaround

LCVs are reduced to a satisfactory level and in some cases completely eliminated

by installing both a long cable between the router and terminating device and

baluns in series on the rx and tx pair similar to the following -

RJ45socket --120ohm balun ---- 75ohm ---- balun 120ohm-----RJ45socket

or shielded RJ45 cable

[wochanda]

When you do a 'show interface' are the output packets incrementing, or output drops?

You could be running into a VC stuck issue (output queue getting full and not dequeueing packets). To check, next time the problem happens issue a 'show queueing interface atmX/imaY'.

If you see the VC queue at 40/40, or 41/40, you've got an VC stuck/wedged issue. This is definetly an IOS bug and you should either check the bug tool, or open a TAC case.