Re:Why firewalls won’t matter in a few years
by scurvy on Friday May 29, 2015 @06:30PM
(#9627895)
Probably a lot. I'm not sure exactly what it is though. If it were that easy, we'd have line-rate firewalls from every manufacturer. Considering that the performance rates are much lower, there are indeed challenges.
Tuple based hashing can get complicated and is highly dependent upon the installation. Some would want source IP. Some want destination IP. Some want a mixture of destination IP and source IP and port. How much you can get through each core (in aggregate) definitely impacts throughput.
Think of a volumetric DDoS attack that rolls into a network over a single path and overwhelms a 1/10/40/100G link. You could have a dozen of those links, but your throughput is hosed because that link is effectively saturated. It might only affect 1/12 of your capacity, but you can't use any of the other links. I hate to bring BGP pathing into a firewall discussion, but maybe it makes sense.
Tuple based hashing can get complicated and is highly dependent upon the installation. Some would want source IP. Some want destination IP. Some want a mixture of destination IP and source IP and port. How much you can get through each core (in aggregate) definitely impacts throughput.
Think of a volumetric DDoS attack that rolls into a network over a single path and overwhelms a 1/10/40/100G link. You could have a dozen of those links, but your throughput is hosed because that link is effectively saturated. It might only affect 1/12 of your capacity, but you can't use any of the other links. I hate to bring BGP pathing into a firewall discussion, but maybe it makes sense.