Hi folks
I have a linux box in my LAN with :

RH 9 , iptables-1.2.6a-2 , kernel 2.4.18.-14 , iproute-2.4.7-5 , squid-2.5.STABLE1

valid IPs : --
invalid IPs : --

ifconfig eth0 netmask broadcast
ifconfig eth0:0 netmask broadcast

route add default gw

iptables -t nat -A POSTROUTING -s -o eth0 -j SNAT --to

this box is my gateway; everything is good : my users can ping the internet, use http and ftp and . . .
but there is a problem :
when they want to login with yahoo messenger sometimes they can , and sometimes they can't

any idea?

thanks in advance