MSN messenger behind Firewall+NAT

I have a Linux box with a Firewall and behind windows clients aiming to use
MSN messenger, I am using NAT so the LAN has private IP's, I just want to
allow the instant messaging services, I don't care by now about the file and
video/voice transfers.

Which rules should I configure in the Firewall ?
I checked a Windows XP SP2 firewall configured to let MSN messenger go
through and it was allowing the following ports:

TCP->8653 and UDP->8661

I tried with these ports and it didn't work, I cheked in the Internet and I
found out that instant messaging uses 1863 and TCP, I tried with this but it
didn't work either. So does anybody know which ports to configure and how
(which direction) ?

Thanks a lot !

Dear Daniel,

U better try with this

# MSN Messenger

iptables -A INPUT -p tcp --dport 1863 -j ACCEPT
iptables -A OUTPUT -p tcp --dport 1863 -j ACCEPT
iptables -A FORWARD -p tcp --dport 1863 -j ACCEPT
iptables -A FORWARD -p tcp --dport 7801:7825 -j ACCEPT
iptables -A FORWARD -p tcp --dport 6891:6910 -j ACCEPT
iptables -A FORWARD -d 64.4.13.0/24 -j ACCEPT

Daniel Camps wrote:
> I have a Linux box with a Firewall and behind windows clients aiming
to use
> MSN messenger, I am using NAT so the LAN has private IP's, I just
want to
> allow the instant messaging services, I don't care by now about the
file and
> video/voice transfers.
>
> Which rules should I configure in the Firewall ?
> I checked a Windows XP SP2 firewall configured to let MSN messenger
go
> through and it was allowing the following ports:
>
> TCP->8653 and UDP->8661
>
> I tried with these ports and it didn't work, I cheked in the Internet
and I
> found out that instant messaging uses 1863 and TCP, I tried with this
but it
> didn't work either. So does anybody know which ports to configure and
how
> (which direction) ?
>
> Thanks a lot !