NAT - Many to One - Specific natting on Source IP Address

[Stephen Carter]

Hello Gurus I've got a NAT question

Plan - The config below refers to .22 as a host - this is for example only.

Hosts in 11.11.11.0/24 should be able to ping etc to 22.22.22.0/24 hosts, and hosts in 12.12.12.0/24 should be able to ping etc to 33.33.33.0/24.

This 33.33.33.0/24 is natted to 22.22.22.0/24.

So, referring to the enclosed diagram, I have in a test lab, scenario '1', whereby host 11.11.11.11 can ping 22.22.22.22, and host 12.12.12.12 can ping 33.33.33.22.

This works by way of placing an IP NAT OUTSIDE SOURCE STATIC command on ROUTER 'A',

ip nat outside source static 33.33.33.22 22.22.22.22

and placing IP NAT INSIDE SOURCE commands on ROUTER 'B'.

ip nat pool 33 33.33.33.22 33.33.33.22 prefix-length 30

ip nat inside source route-map 22 pool 33

access-list 100 permit ip 22.22.22.22 0.0.0.0 12.12.12.0 0.0.0.255

route-map 22 permit 10

match ip address 100

This is all fair and well, but in the real world I only have access to ROUTER 'B', as per scenario '2'.

So the question is :- 'How do I do destination specific Natting on router B, so hosts in subnet 11 can speak to subnet 22, and 12 can speak to 33.'

Any help gratefully received.

Stephen

[nkarthikeyan]

Hi Stephen,

In your case you can make hosts behind the router to talk to hosts behind router A..... if the hosts behind the router A is configured with one to one mapping or with one ip with port-forwarding for multiple service ports..... Because until and unless you have a permanent fixed ip/service you cannot do so..... same way it is applicable for vice-versa....

say if you ping yahoo.com.... it responds to the ping... because it has fixed ip address for the yahoo server....

Regards

Karthik