[plug] Masquerading ICQ?

[Matt Kemner]

On Wed, 2 May 2001, Bernard Blackham wrote:

> With kernel 2.4.x I believe it'd be possible to use it's improved
> firewalling setup to forward particular ports to particular machines and
> set the option for ICQ to say "I can receive connections on this range of
> ports". I've never done it before, but I suspect it should work. Anyone
> tried this?

You don't need 2.4.x for that. It works great on 2.2.x and even 2.0.x, but
the syntax differs.

Under 2.0.x you would do:

ipautofw -A -r tcp 2000 2020 -h <IP of machine running ICQ>
ipautofw -A -r udp 2000 2020 -h <IP of machine running ICQ>

Under 2.2.x you would do:

port=2000
while [ $port -le 2020 ]
do
  /usr/local/sbin/ipmasqadm portfw -a -P tcp -L <gateway ext IP> $port \
                                             -R <ICQ IP> $port
  port=$(($port+1))
done


And then configure ICQ to use only ports 2000->2020

Note that if you don't have a static IP, your gateway ext IP will change
so you will need to re-create the rules every time you dial in (which is
what /etc/ppp/ip-up comes in real handy for)

 - Matt