[Nosferatu de-cloaks]
To Do a) The email server should be able to send POP & SMTP requests to our email service providers server ie 10.10.10.10 via our gateway server
iptables -t nat -A POSTROUTING -o eth1 -j SNAT --to 55.55.55.55
b) Users from internet should be able to access our internal email server i.e. 77.77.77.77 via our gateway server 55.55.55.55
iptables -t nat -A PREROUTING -i eth1 -d 55.55.55.55 -p tcp --dport 80 -j DNAT --to 77.77.77.77:80
iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE iptables -t nat -A PREROUTING -i eth1 -p tcp --sport 80 -j DNAT --to 77.77.77.77:80
Just lil' glitches! You are doing good :) More rules can/should be added depending what kind of firewall you are trying to setup.
TC,
[Nosferatu cloaks]