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New Member

PIX FW failover anomaly


I have redundant PIX 515's running ver. 6.2(1). Every few occasions, the primary PIX FW mysteriously failovers to the secondary. When this occurs, all traffic flowing through the now active FW is being blocked.

I tried simulating a failover using the 'failover active' command on the primary and surprisingly the secondary PIX automatically takes over with no problems.

Did anyone experience this weird anomaly? Please respond if you have possible suggestions or troubleshooting tips that I may use to resolve this issue.


New Member

Re: PIX FW failover anomaly

Hi Marvin,

I have had this problem in the past. If you are plugging your firewalls into a switch, you must make sure that spanning tree is disabled for the failover to function properly.


New Member

Re: PIX FW failover anomaly

Neil or anyone else,

Am i correct on the reasoning of your statement of disabling spanning tree?

...So if a link goes down on the Primary PIX FW, say inside i/f, status will remain failed and not go into standby because the switch port that the inside interface is on will remain in blocking state. In order for the failed primary to become a standby, the inside i/f must be able to transmit hello packets. With a blocked port, due to spanning tree enabled, the failed primary will never be able to become a standby to the now active secondary.


Re: PIX FW failover anomaly


Do you have a syslog server setup ? What does the syslog shows? Any traceback on the console? Thanks,


New Member

Re: PIX FW failover anomaly

Make sure and disable all unused ports or run crossovers between the two firewalls. This will cause failover to occur.