PIX DoS?

[rgonzaga]

I'm new to these firewalls so I'm not sure if this is a hack or something else. Every once in a while I get the following logged to my syslog server:

%PIX-4-500004: Invalid transport field for protocol=17, from 213.217.176.56/1599 to 255.255.255.255/0

Right after this happens my PIX is unable to reach my url filter (websense). Everytime. What's going on and how can I prevent it?

Thanks for any help.

[David White]

This message indicates that the source: 213.217.176.56 is sending a UDP packet with a destination port of 0. In your case it also has a broadcast address for the Destination. This should not have any impact on the PIX being unable to reach Websense.

Sincerely,

David.