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New Member

Is NAT possible in this situation?

this is on a 3725 router, assume that the 10. addresses are public and the 192 addresses are private.

int fa0/0 - internet side

ip address

int fa0/1 - lan side

ip address

int fa1/0


int fa1/1


I have public addresses on the inside that get routed out of course. I also have 2 192. addresses that I would like to static nat to 2 of the 10.1.2 addresses. Is this possible since the public address that I want to nat to is on the inside interface? If not is there another way to make this work without modifying or adding another ip to fa0/0 wan interface?

New Member

Re: Is NAT possible in this situation?

Not sure, But you can try like this.

Add seconday IP (192) to the inside interface (Fa0/1)

Do a static NAT for 192. servers.

Keep public IP's as it is.

Other way round -------

simply assign private IP (192.) to all servers inside LAN.

Change Fa0/1 IP to private IP.

And do static NAT for all servers.

New Member

Re: Is NAT possible in this situation?

I don't quite understand your response, however if this clarifies a little more here goes. I have public and private addresses inside and I want to nat private inside addresses without using the address on the outside interface. I am getting the feeling that this is not possible. I want to NAT to one of the public addresses that is on the inside interface.

New Member

Re: Is NAT possible in this situation?

Well,I am assuming here too LAN pools.

First 192.168.0.x/24---Private address space

Second 10.1.2.x/24---Public address space

Router WAN (NAT outside I/F)

Router LAN primary ip is,(NAT inside I/F)

secondary address

Pc1 ip address

Pc2 ip address

Now routing is conerned both PC's can talk to my router.

If you are using dynamic NATing in the same router first deny,(Use access-list)any source from Public address space.

Pc2 will be able to communicate to internet without any NAT translation taking place.

For PC1 NAT translation can be configured as to get eighther overload from Fa0/0(outside I/F)


Use static NAT to Public LAN address space ( or ...etc.(which ever is free address)

New Member

Re: Is NAT possible in this situation?

Thanks, I will give this a try.

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