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NAT Question on 12.1 IOS

ALIAOF_
Level 6
Level 6

- I have an older router 2600 running 12.1(4) IOS.

- There are a few clients connected to it via the frame relay connection.

- There is an IP that clients access 192.168.1.10 for example

- We need to do a NAT for this IP for one specific client only like "ip nat inside source static 192.168.1.10 1.1.1.1"

- However if I do that, that will effect other clients too

- On the interface for this client I'll be using "ip nat outside"

- Is there a way to accomplish this without effecting other customers?

6 Replies 6

pascal
Level 1
Level 1

Not sure with an IOS that old, but off the top of my head, I would try:

ip nat inside source static 192.168.1.10 192.168.1.10 extendable

ip nat inside source static 192.168.1.10 1.1.1.1 extendable

What is the purpose of "extendable"

Hi,

To allow static NAT mappings of one IL address to multiple IG addresses, the keyword extendable is added to the end of the mapping statements


There are two situations where you need to use the extendable keyword.


1.) When there are multiple translations with the same source and the protocol / port is not specified.
ip nat inside source static 1.1.1.1 1.3.2.2 extendable
ip nat inside source static 1.1.1.1 1.2.2.2 extendable


2.) When there are multiple translations with the same source and the protocol / port is the same.

ip nat inside source static tcp 1.1.1.1 22 1.3.2.2 22 extendable
ip nat inside source static tcp 1.1.1.1 22 1.2.2.2 22 extendable


If the ports are different, even if the source is the same, the extendable keyword is not needed....



Please rate the helpfull posts.
Regards,
Naidu.

Thank you for the reply do you mean

"ip nat inside source static 192.168.1.10 1.1.1.1 extendable" (Original NAT)

"ip nat inside source static 192.168.1.10 2.2.2.2 extendable" (For one specific client only)

"So since we are putting in both and using the extendable keyword both of them will work?

Because goal is to create a static NAT for 192.168.1.10 IP for one client only without effecting other clients.

And what is "IL Address" and "IG Address"?

Hi,

Can you be clearer in what you're trying to achieve?

IL= Inside Local = the address you're seeing in your network it is usually the private RFC 1918 address you're natting

IG= Inside Global= the public address which outside hosts use to communicate with your private address

Regards.

Alain

Don't forget to rate helpful posts.

Thank you, sorry I always use the full two words so didn't realize it, but thank you for elaborating.  Any ways here is the summary:

- I have an older router 2600 running 12.1(4) IOS.

- There are multiple clients connected to it via the frame relay connection.

- There is an IP that clients access 192.168.1.10 for example

- We need to do a NAT for this IP for one specific client only like "ip nat inside source static 192.168.1.10 1.1.1.1"

- However if I do that, that will effect other clients too because rest of the clients get to that IP via 192.168.1.10

- On the interface for this client I'll be using "ip nat outside"

- Is there a way to accomplish this without effecting other customers?

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