Statefull failover in High Availabilty /clustering firewalls

[Don Ng]

Hi all, Checkpoint firewalls have intrinsic load balancing capabilities, and they have stateful failovers between the active and standby firewalls.  Meaning in this case there would be no need for the client to re establish the connection via the 3 way handshake.      So when packets arrive at the firewall with non expected sequence numbers, they are still let through as long as the ip address are ok?  <no hands on on checkpoint, based on literature>     I have come across clients that state their primary worries was the integrity of the databases in opting for this solution. As they fear a situation in where a firewall goes down and a transaction is lost, especially for financial transactions.    My question is. 1.0 From a security viewpoint would stateful failover of firewalls be a plus or minus. 2.0 Is it that difficult to ensure that the DB be consistent without depending on external devices, I mean this would involve       greater resources on commits, precommits etc. 3.0 What is the probability of an attacker being able to trigger a stateful failover and taking advantages of this.   Nothing too heated please.   Thanks and regards Don Ng