Simple firewall setup question

[Bruno.Bossier@comparex.be]

I have the following setup :

2 SUN solaris 8 servers both connected to each other via a PC running SuSE
Linux 7.3 with ip_forwarding on.

I would like to use iptables to block all transfer between the 2 servers,
so therefore I did this :

iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

Only on certain moments, I would like to make an ftp transfer between the 2
SUN servers, so I need to allow access on the Linux server to do that. What
do I need to do ? I would like to keep it as simple as possible.

Bruno