cannot Telnet to a router with DLSW and OSPF

[abekeris]

sometimes we cannot telnet to a router configured with DLSW and OSPF.

Could be a problem with the TCP stack ?

[a.awan]

Are you actively monitoring the cpu utilization of the router? If the CPU is running very high that might prevent the router from responding to telnet requests.

[jishi]

use "sh proc cpu history" to get the CPU utilization information.

Jing

[jvogler]

Also, verify your exec timeout on your VTY config is not set to 0 0 or extended times. If this is set, make sure you actually exit the telnet session and do not just kill your terminal session.

(0 0 = hours minutes)

[abekeris]

this could be the problem....I will configure it to 0 30 then I'll check...thanks...

[abekeris]

I test with the exec-timeout and it doesn't work. I don't have users connected, dont have ACL's configured and we still cannot telnet the router.

Any idea ?

[abekeris]

The CPU is almost at 5%.

[jishi]

Can you telnet to the router to itself when you are on the console? If the CPU utilization is not high, do a debug tcp trans while you are telneting from the console.

Jing

[jishi]

BTW, what platform are you using? And which specific interface you are trying to telnet to? Can you please give the output of sh line?

Thanks

Jing

[ganganathshanmugalingam]

sometimes you cannot telnet means sometime you can telnet successfully.

There may be old telnet sessions present at the router.

#sh run | beg vty

to see how many vty sessions available for your router.

#sh user

to see how many telnet sessions exist.

if there are more than one vty sessions then you can clear the old one.

[jclerico]

Hello, I have the same issue on a C7200 router.

Check if you have "ip tcp timestamp" in global config. If so, remove this command and reload the router. Let me know. Here is my e-mail: clericoj@fr.ibm.com