I have always wondered how two firewalls on the same level worked. I even asked some of hte network admin guys at work and they didnt seem quite sure. If you get past a hole in firewall A is it possibly for firewall B to pick it up? how do the firewalls know which is to handle what packets?
it just seems like there is alot of room for collisions and errors.
To try and figure this out long ago I ran zone alarm and some other firewall at the same time and zone alarm seemed to pick everyhting up first such as when somehting would access the internet and when i had a friend nmap me zone alarm seemed to block most of the requests.
So maybe one of you network guys could clear up how this works.