The SSH session to PIX 535 with software version 7.x firewall times out frequently

[TCC_2]

What is SSH?

"Secure Shell (SSH) is protocol used for secure data communication. It works on server and client model (SSH server and SSH client at user end). The protocol have two major versions known as SSH-1 and SSH-2.

Core issue

The problem occurs in version 7.1 under these circumstances:

• The ssh timeout command is set to the default in the PIX Firewall configuration.
  
• The sysopt connection timewait command is issued. This issue is documented in Cisco bug ID CSCsd53321.

Here the Secure Shell (SSH) session times out about 20-30 seconds after the sysopt connection timewait command is issued in the PIX configuration.

Resolution

To resolve this issue, set the ssh timeout value to anything other than the default of five minutes. The session then timeouts in that period.

Alternatively, leave the ssh timeout at the default of five minutes and simply reboot the device after the sysopt connection timewait command is added.

To upgrade to version 7.2(0.74), refer to Software Upgrade: Cisco PIX Security Appliance Software.