Natting of Destination Address

[dloskot]

Is is possble to nat the destination address. What I am trying to do it change DNS servers. I would like to have traffic going to the old address be natted but traffic going to the new address not be natted. Finally if the DNS devices generates traffic it would not be natted.

[Mark Turpin]

Sure, if you place your DNS servers on the 'inside' interface of the NAT and have your non-migrated network on the outside.

This may or may not be possible in your environment.

Additionally, your requirement of no nat on the way back out may be a bit tricky to achieve.

Perhaps you could elaborate a bit on your layout?

[dloskot]

I understand it may be tricky, that is why I posted it. The DNS server is an internal server so from the router point of view I can make it either inside or outside. Currently it is connected directly to a 6509, but the thought is to put a 3640 between the DNS server and the 6509 and using static routes on the 6509 direct traffic for either address to the 3640 and then to the new server. My thought was to do nating on the 3640, but as I indicated I have not be able to get the router to change or nat the destination address and also not to nat traffic to the new address or new traffic coming from the DNS server.

If you are someone could give a specific config or point me to a cisco document that explains how to do this it would be great.

[attrgautam]

I had a scenario some time back. I had a server which had to be reached from the internet but could permit only pvt IPs. SO i used something known as Nat outside which modified the SRC of the remote end IPs to a PVT IP of my Choice.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f8e.shtml

Check this out and let me know if it helps you