Port Forwarding- Want to keep Port 587 incoming closed

dman777 · 10-20-2011, 09:12 PM

I have a postfix server running on my kvm guest. It is just for pushing emails...not pulling. The postfix server sends out email to the internet through port 587. i would like to have the incoming port 587 closed and have another port used and forwarded through the firewall...and then have the port 587 used. Is that possible? I tried to use port 5577 and have it forwarded to port 587 for incoming....useing the nat table/POSTROUTING chain. But when I tried this my host could not communicate to the Postfix KVM guest.

hen770 · 10-20-2011, 09:27 PM

Are you mean that the host system should forward from someport to the guest's 587 port?

dman777 · 10-20-2011, 09:33 PM

I want my host that the kvm postfix guest sits on to be able to communicate with the kvm postfix guest. but i don't want to open up port 587 for incoming traffic...so i wanted to use port forwarding instead so port 587 still can be used after the traffic gets through the firewall.