Hello:

I currently have a completely routed (about 70 routers) network that uses private IP addresses masqueraded to a public IP address. If a customer needs a public IP address I have used 1-1 natting in the past.

I have a big customer that is insisting in a "real" public IP address and was wondering how I would combine running some public IP addresses up our network in parallel with the existing private network? Has any one done this? What tips should I be looking for, I'm curious about what I have to do with my default routes in my routers...?

Thanks for any tips that you might be able to give me,
Ken

This is done through Proxy-Arp, it is not specific to Mikrotik, there's an RFC on it and runs on most service provider grade routers. Google to find out more, or check the Mikrotik manual for more information.

This has been discussed in the past on these forums so you might also try searching for "proxy arp" and you might find some additional help.

With a decent sized network this could prove to be a complex configuration task, however I'm not sure how hard it is to configure as I have yet to implement this feature.

Here's a good explanation: http://linux-ip.net/html/adv-proxy-arp.html