[oclug] firewall noises

[Joe Burpee]

Dave Edwards wrote:
> On Thu, 22 Mar 2001, Michael Hong wrote:
> >  I noticed that if I block port 113, sending
> >    out mail to my ISP's smtp server and connecting to some ftp sites hangs.
> I'm relieved to see this.  The same happens to me.  Likewise gnapster.

It occurred to me that I'm probably not being very clear.  (What else is
new?)  All I'm really suggesting is that you insert something like the
following line

ipchains -A input -i ppp0 -p tcp -d 0/0 auth -j REJECT

ahead of your general input chain DENY rules.  This assumes your
external interface is ppp0; otherwise use eth0 or whatever it is.  Note
that `auth' is just port 113 (ident) in /etc/services.

Then restart your firewall.

Joe