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Telnet services keeps disabling

shirwaziri1_2
Level 1
Level 1

I have a client with several 3500 switches. Every 1 or 2 months, the telnet services disables. Productions is not effected. Only problem is i can't telnet to the switch. This is happening to more then 20 switches in the network. And it is like a domino effect. The only way to get telnet back up and running is to reboot the switch.

I did see a high memory being utilized by the Http/https so I disabled it. The problem went away for some time but is back again.

Any clue??

8 Replies 8

Amit Singh
Cisco Employee
Cisco Employee

What is the IOS running on the switches. What is the exact module number of the switches. Please paste the config for one of the switch.

-amit singh

I checked several and all have the following details:

Model # Cisco WS-C3550-24-PWR

Cisco IOS Software - C3550 Software (C3550-IPBASEK9-M), Version 12.2(25)SEE, RELE

ASE SOFTWARE (fc2)

unfortuantely i can provide the show run

kerek
Level 4
Level 4

Have you checked further what is the cause of high cpu utilization? If this is happening on all switches then it refers to some kind of traffic storm which is killing the switches.

the only cause i can think of is that they use alot of these switches for video and web conferences. Also at times the workers play online video games..which they should not.

Other then that, what would be the best way to find out how to find high cpu utilization on thier network?

Hi,

What do you see when issue the "show proc cpu | ex 0.00% 0.00% 0.00%" command? It will probably show which process eats the cpu.

Hope it helps,

Krisztian

i have attached the show proc cpu | ex 0.00% 0.00% 0.00%

The switch that has telnet service down, there is no whay to get in. But i have provided the show proc cpu | ex 0.00% 0.00% 0.00% for the switch that is on the same floor.

Ok, telnet is not down, but it is up and down. I did manage to log into it. And found some very odd behavior.

1. I tried to run the show proc cpu and it goes back to the prompt.

2. also, just for kicks, i did a wr mem.

her is what happened.

MOH-3550ADMIN-FL-20-2#wr mem

%No memory available: Update of NVRAM config failed!

MOH-3550ADMIN-FL-20-2#

Check the bug navigator for memory leak bugs for the version you are running . Also make sure you exec-timeout parameters set for all your vty lines.

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