In message <[EMAIL PROTECTED]>, "Tony Hain" writes:
>
>Mangling the header did not prevent the worms, lack of state did that. A
>stateful filter that doesn't need to mangle the packet header is frequently
>called a firewall (yes some firewalls still do, but that is by choice).
>
Absolutely correct. Real firewalls pass inbound traffic because a
state table entry exists. NATs do the same thing, with nasty
side-effects. There is no added security from the header-mangling.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb
