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New Member

4507R+E users unable to renew DHCP reservations

Our users are unable to renew their DHCP reservations and loss of connectivity to our 4507R+E via SSH occurs during this time. Also, we are unable to ping our core 4507R+E during this time as well. We temporarily fix this issue by reloading our core 4507R+E. This issue has been recurring every 4-5 weeks but sometimes sooner.

Recently, we discovered 3 1GIG ports (ESX) on our 4507R+E were not configured for their respective VLANS. This has been corrected but not sure if this issue is related to our users DHCP renewal issue. Is it possible that data from these ports could have been flooding our 4507R+E (core) and eating  up CPU and mem until our core crashed?

We are currently monitoring through Solar Winds and collecting cpu and mem statistics using the commands listed below. Any assistance would be greatly appreciated.

sh process me sorted

sh process cpu sorted

Thank  You,

Doug

6 REPLIES
Green

4507R+E users unable to renew DHCP reservations

Dougie,

Sounds like you may be suffering a high cpu issue

Have a look at this link.

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/troubleshooting/cpu_util.html

Regards,
Alex.
Please rate useful posts.

Regards, Alex. Please rate useful posts.
New Member

Re: 4507R+E users unable to renew DHCP reservations

                   Alex,

                   I've attached our current mem and cpu status for our 4507R+E. The cpu seems to have always been operating within normal ranges. Even when we recently crashed and the show tech-support was only showing our CPU at 24%. I'm thinking it may have something to do with a hung process or data flooding our core using up the memory. Any other suggestions?

               Thank You,

               Doug

Green

Re: 4507R+E users unable to renew DHCP reservations

Doug,

I have looked at your file.

Like yourself I dont see anything obvious.

Try checking the Cisco bug tool for your sup & IOS version.

It may be you need to ugrade/downgrade your IOS.

Regards,
Alex.
Please rate useful posts.

Regards, Alex. Please rate useful posts.
New Member

Re: 4507R+E users unable to renew DHCP reservations

               Alex,

               Attached are 2 more files. I noticed the pool manager under IOSD seems pretty high. Also, I found another blog through google that mentioned the k9npe for a cisco router has a memory leak and wondered if the same could be true for the universalk9npe.spa.03.04.00.SG.151-2.SG.bin we're currently using. I've looked up this IOS under the caveats and field notes but can't find anything about a memory leak for this version.

               Thank You,

               Doug

Green

Re: 4507R+E users unable to renew DHCP reservations

Doug,

I have looked the bug tool.

Looks like you are hitting bug  CSCue76243

Symptom:

Sup7E, Sup7LE or 4500X loses all L3 connectivity to/from switch IP address. Switching continues to work, but IP traffic to/from the switch does not. This includes snmp, ntp, telnet, ssh, etc.

Conditions:

Sup7E, Sup7LE or 4500X using 3.4.0SG

The problem occurs when there is significant CPU bound traffic on Fa1 port.

Workaround:

Disable CEF on the L3 interfaces to temporarily restore service (but it will be software switched). Once the problem occurs, the switch must be rebooted. To prevent the problem from occurring, shut down Fa1. If Fa1 is shut down, the problem will not appear.

UPGRADE TO 15.1(2)SG1

Hope this helps

Regards,
Alex.
Please rate useful posts.

Regards, Alex. Please rate useful posts.
New Member

Re: 4507R+E users unable to renew DHCP reservations

Alex our FA1/1 port is currently down/down. Does this need to be Administratively Down for the fix to work? I will be updating our software to the suggested version but will check this release out before upgrading.

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