3750- is working but cant telnet and memory full msg

ch_sajid_hussain · ‎01-02-2010

I have a big LAN of more than 500 cisco devices. Problem is with one of 3750 switch. its working and its child switches are also working. but when i try to telnet it, its memory full msg comes and also seems to be down in Cisco Network Assistant. I cant restart this switch also. need urgent attention plz

glen.grant · ‎01-02-2010

You are not the first person to see this and it's something cisco needs to address seeing the widespread deployment of this model switch . I can only speculate as to the cause but it may have to do with stackmaster switch having the complete responsibility for the whole stack for configurations and all the other functions of the switch except it has to do it for a whole stack which could be 7 or 8 switches and if it does not release memory like it should it creates a memory leak and eventually the memory resources run out. We have seen this on a stack and unfortunelty the only way to recover this is to reload the stack which is obviously disruptive and a poor fix to a problem . In the stack we saw it in there is only about 6 vlans and 6 SVI's configured for the whole and not ver many acl's etcc that might chew up memory. I have heard and seen other users complaining about the same issue.

taudinchabot · ‎09-24-2010

Hi Sajid

I have the same issue. a few stacks of C3750 form my core and distribution networks. Since the last few weeks, I experience exactly the same as you describe.

CNA is blind, telnet isnt working, and when connecting using the console the only message it can get out is that its memory is full.

A collegue of mine found out that it can be the combination of IOS and the HTTP server (needed for CNA...) so I will look for a new IOS, and disable the http server in the mean time

Did you solve it?

Regards,

Quirijn

sumitava123 · ‎09-24-2010

Hi ,

It is normally caused by some bug on the IOS . The only solution is to reload the switch. Then keep checking the process utilisation and keep a track of the processes which is continuously using most of the memory. Along with that open a TAC case aswell.

Hope this helps

Sumit

krahmani323 · ‎09-24-2010

Hi All,

I have also met this issue some times. Impossible to log on 3750 (for 2960 also) with following message % Low on memory; thy again later % . CNA was used.

Depending on the IOS version we shoul match this bug :

CSCsz79652 Bug Details

Memory leak in *dead* memory

Symptoms
A memory leak may be seen in *Dead* memory.

Conditions
This issue occurs in IOS version 12.2(50)SE and l2.2(50)SE1. IOS version 12.2(44)SE is not affected.

The problem occurs when using Cisco Network Assistant to poll the device.
ip http server< /CmdBold> or ip http secure-server< /CmdBold> need to be enabled for the leak to occur.

Workaround
Disable the http server or stop CNA from polling the device.

Regards.

Karim

taudinchabot · ‎09-27-2010

This was indeed the bug which was found by my collegue.

I have disabled th http server, but am also not able to monitor using CNA anymore.....

Waiting for CNA 5.6, and upgrade the IOS on all my switches next weekend.....

Thanks for the efforts!

rolfwolff · ‎12-14-2010

Hello.

Any news about it?

Thank you.

Kind Regards,

Rolf