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Major Issue with switches following problem with PCM Policy

Jason Scott
Regular Advisor

Major Issue with switches following problem with PCM Policy

Hi All,

We had a problem with a PCM policy which had a typo in it. After PCM tried to send out the policy and failed we could no longer telnet to any of our switches (2600 series).

I have since found that the first telnet will fail but the second telnet will work. Issuing show telnet provides the following:

Telnet Activity

Session Privilege From To
------- --------- ---------------
1 Superuser Console
2 Manager ---.---.---.---
** 3 Manager 10.177.29.251

The #2 session seems very suspicious. Subsequently trying to kill that session freezes my active session. Now some of the switches are reporting that too many telnet sessions are active and we've lost complete access. The only way to cure this at present is to reload the switch via the web interface, but with about 70 in a production network I cannot easily do this.

Are there any known bugs that cause this type of behaviour?

Will telnet sessions eventually expire?
4 REPLIES
Jason Scott
Regular Advisor

Re: Major Issue with switches following problem with PCM Policy

Some additional information, once the switch is rebooted via the web interface it displays the following crash error:

System went down: 03/01/07 14:36:53
Saved crash information:
Software exception at exception.c:373 -- in 'tHttpd', task ID = 0x17c0260
-> Memory system error at 0x16f3790 - memPartFree

Jason Scott
Regular Advisor

Re: Major Issue with switches following problem with PCM Policy

Another little piece of info: If you can still telnet to the switch but issue a reload command it says its unable to because a file transfer is in progress, despite none actually occurring.
Matt Hobbs
Honored Contributor

Re: Major Issue with switches following problem with PCM Policy

Jason, I have seen this occur a few times and ... it is very annoying.

One thing that can cause it is by sending Ctrl-s to the telnet session - this will pause the screen. If at this point, you kill that session - you will end up with those ---.---.---.---. As you've stated, if you try to kill those sessions, it will just freeze the next one, and so on.

To unfreeze a ctrl-s pause, you need to type ctrl-q. If you've already tried to kill the session via the 'kill' command though it's too late.

Thanks for the idea of simply rebooting it through the web interface. I'd found the 'file transfer in progress' symptom and could only think of the reset button on the front. (The sessions never expire due to console inactivity-timer)

What was the typo in the PCM policy that triggered this? I would be very interested in this.

I'd also recommend you open up a case with HP support.

Matt
Mohieddin Kharnoub
Honored Contributor

Re: Major Issue with switches following problem with PCM Policy

Hi

Its really annoying thing, but the problem is if we don't have a physical access to the switch, and WEB interface (disabled or a security policy ....), then the only thing that should work is the switch should kill the expired sessions by it self due to inactivity for a certain period of time.

And since ProCurve switches don't have a Default Inactivity timer set by default, no one will remember to set it up, (i kept it as one of the implementation steps in any project).

I hope with the new releases of firmwares its set by default to some period (like 30 minutes MAX) because its called Intelligent Switches, do they .....?

:)

Good Luck !!!
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