Public and Private IPs on same interface

Hi people,
Is it possible to have public & private IP’s on the same interface ?
Basically the router has 2 interfaces, one facing the internet, one facing our LAN. The internet interface currently has 1 public IP. There is also a block of 64 public IPs routed from our ISP to our router(to our public IP, which is not part of the block of 64). A traceroute of any of the IPs from the block of 64 IPs reaches our public IP just fine. Our private side of the network is nothing fancy, 192.168.10.0/24. Currently everything from the private interface is NAT’ed, and appears on the internet as The Public IP on our public facing interface. Everything is just fine so far. Now though, I need to assign Public IP’s from our block of 64 to machines on our LAN. These IPs should be routed normally, giving true end-to-end connectivity, and should be accessable from the internet, without NAT’ing or mascarading. What commands do I need to issue to the router to enable these IPs on the LAN interface, and for them to be routed properly?. I also believe from my reading of my current configuration that everything on our LAN interface is currently NAT’ed, regardless of its source IP, I presume I would need to change this somehow so only the private IPs are NAT’ed, while the public IPs are routed through the router correctly.
I hope this makes sense and somebody can help me.

Kind Regards,
Niall


Yes, and welcome :wink:
as far as i have experince, it’s possible one nic for local and public interface.
read here: http://forum.mikrotik.com/t/masquerade-on-public-eth-with-in-traffic-on-the-same-eth/14655/1

regards
Hasbullah.com

very simple solution is to set up your masquarade rule that it masks only LAN addresses and real IP’s are routed, everything should work flawlessly.

look here for more information:
http://www.mikrotik.com/testdocs/ros/2.9/ip/nat.php

Thanks for that guys.
After some further studying of the manuals everything makes sense now, one can never read those things too many times :slight_smile:

Niall