How NAT works in this design?

paulnigel · ‎08-27-2007

Hi forum,

we were given this network design in order to integrate with another company's network. Network A is our network running EIGRP, Network B is our partner's network running EIGRP as well.

R1(router) will policy route traffic that has been changed to 172.16.0.0 to R2, and will policy route those conflicting IP address to R3 before going to R2.

How should I configure my DNS in this case? How NAT actually works in this case?

Thanks much,

pn

Pavel Bykov · ‎08-28-2007

DNS in your network should point to translated addresses of the other network.

NAT works both ways in this example, so devices in one network communicate to OUTSIDE LOCAL address, which is translated afterwards to the OUTSIDE GLOBAL.

In your example:

Perspective 1:

NET1 192.168.0.0/16 = inside local

NET1 172.16.0.0/16 = outside local

NET2 192.168.0.0/16 = outside global

NET2 172.16.0.0/16 = inside global

Perspective 2 is reversed.

These two documents will help you understand the concept better:

http://www.cisco.com/en/US/customer/products/ps6640/products_white_paper09186a0080091cb9.shtml

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f30.shtml

Hope this helps.

Plese rate all helpful posts.