Private Ip's on the net??

roopunix · 06-30-2005, 12:41 AM

Hello all my isp is saying that my local lan ip 's are requesting the internet

here is my configuration

Redhat9

/sbin/iptables -t nat -A POSTROUTING -s 172.16.100.0/16 -o eth1 -j MASQUERADE

my ipv4 forwarding is set to 1 at /etc/sysctl.conf

My iptables chains are set accept policy.What may be wrong.But Still i am able to surf the internet. and one more thing how do i know that my private ip are going outside.

Thanx

eantoranz · 06-30-2005, 10:01 AM

Well... I wouldn't check for source address in that line, just the output device:
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE

If you left it like that, then If I connected to your lan not in that address segment, (and supposing your router could route traffic to my host), it could be possible for me to get traffic with lan's address to the internet (cause I wouldn't match that rule).