On May 11, 2011, at 10:03 PM, phocean wrote: > - DDoS : anyway, a firewall isn't more susceptible to DoS than the server it > protects. If you look at the hardware performance of modern > firewalls, if an attacker has the ability to DoS it, then only a considerable > server farm that very few companies can afford will be able to sustain it.
My operational experience, including that acquired during my tenure working for the world's largest manufacturer of firewalls by units shipped, contradicts this statement. > - stateless scales badly on large networks, because it requires much more > complex and lengthy rules if you are serious with security. This is a) untrue and b) a near non-sequitur. In general state is much more harmful on larger networks than on smaller ones; and there's no correlation at all between the size of a network and the complexity of network access policies. > Another advantage of stateful is that there is a first sanity check of the > sessions on a specialized hardware rather than on a generic TCP/IP > stack of a bloated server OS. Marketing aside, those 'sanity checks' take place in software, not in hardware; and they actually constitute a greatly broadened attack surface (look at the multiple vulnerability notices/patch notices for any commercial stateful firewall you can name, as well as for open-source stateful firewall packages). > For instance, the network stack of Windows is probably much more prone to > bug/crash due to poor handling of crafted packets than a dedicated > firewall (Checkpoint, Cisco, Fortinet...) may be. Sadly, this is also not borne out by experience. Quite the opposite, actually. ----------------------------------------------------------------------- Roland Dobbins <rdobb...@arbor.net> // <http://www.arbornetworks.com> The basis of optimism is sheer terror. -- Oscar Wilde _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
