Hardware: PIX-515E, 128 MB RAM, CPU Pentium II 433 MHz
OS: Cisco PIX Security Appliance Software Version 7.1(2)
I have two of the above firewalls that are connected with a failover LAN connection. Every couple of months the Primary firewalls beings to deny any new connections through the firewall and I cannot SSH or even console into the firewall. When I try to console into the FW it scrolls all the logging messages and will not allow me to login. I get a weird "command...." message after issuing the "enable" command and get sent back to the user exec prompt.
I have a syslog server running and after that keeps displaying the following message:
"(Primary) Failover message block alloc failed"
Here is Cisco's explanation of the message:
Explanation: Block memory was depleted. This is a transient message and the PIX Firewall should
recover. (Primary) can also be listed as (Secondary) for the secondary unit.
After about 20-30min of no connectivity and the above messages the Primary FW eventually fails over to the secondary FW (on its own) and connections are restored. I don't see any other issues in the log other than the message above.