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 : 1.2.3.140 -- 1.2.3.143
invalid IPs : 192.168.0.128 -- 192.168.0.191


ifconfig eth0 192.168.0.135 netmask 255.255.255.192 broadcast 192.168.0.191
ifconfig eth0:0 1.2.3.142 netmask 255.255.255.252 broadcast 1.2.3.143

route add default gw 1.2.3.141

iptables -t nat -A POSTROUTING -s 192.168.0.128/26 -o eth0 -j SNAT --to 1.2.3.142

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
Pejman