On Sun, 21 Oct 2007 07:31:58 +0300, Al Boldi said:
quoted text
> > Well, for example to stop any transient packets being forwarded.  You could 
> > probably hack around this using mark's, but you can't stop the implied
> > route lookup, unless you stop it in prerouting.
> 
> Basically, you have one big unintended gaping whole in your firewall, that 
> could easily be exploited for DoS attacks at the least, unless you put in 
> specific rules to limit this.

OK, the light bulb just went on... ;)

We actually *do* have an issue with the flip side of that - it's a frikking
pain to make packets that show up on eth0 with a destination of 127.0.0.1
go away un-noticed - or at least I'm assuming it's the flip side of the same
issue.