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New Member

Destination NAT

I am trying to nat the destination address with an ASR router.

Source --- Source IP: 96.97.98.99 Destination IP: 12.34.56.78

Router ----NAT the destination to 10.0.0.4

After NAT Source IP is 96.97.98.99  Destination IP is: 10.0.0.4

I don't seem to be able to find the correct commands.

Any assistance would be appreciated.

K

 

  • WAN Routing and Switching
1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Hi,What you are looking for

Hi,

What you are looking for is in reality a static source NAT. I know that you intend to rewrite the destination of the packets coming from internet to your router so that they can reach your internal server at 10.0.0.4. However, the names "source NAT" and "destination NAT" apply to the traffic that flows from the inside to the outside interface, i.e. from your internal LAN going off to the internet. It is only natural that in the return traffic, the opposite addresses are rewritten, i.e. if the source NAT rewrites the source IP in the traffic going from inside to outside, it will also rewrite the destination IP in the traffic going from outside to inside.

So simply look for a typical static source NAT configuration. While I do not know what ASR you are running (if it is IOS-XE or IOS-XR), on plain IOS, this would be very simple:

ip nat inside source static 10.0.0.4 12.34.56.78

or, with port forwarding:

ip nat inside source static tcp 10.0.0.4 80 12.34.56.78 80

Please give it a try.

Best regards,
Peter

2 REPLIES
Cisco Employee

Hi,What you are looking for

Hi,

What you are looking for is in reality a static source NAT. I know that you intend to rewrite the destination of the packets coming from internet to your router so that they can reach your internal server at 10.0.0.4. However, the names "source NAT" and "destination NAT" apply to the traffic that flows from the inside to the outside interface, i.e. from your internal LAN going off to the internet. It is only natural that in the return traffic, the opposite addresses are rewritten, i.e. if the source NAT rewrites the source IP in the traffic going from inside to outside, it will also rewrite the destination IP in the traffic going from outside to inside.

So simply look for a typical static source NAT configuration. While I do not know what ASR you are running (if it is IOS-XE or IOS-XR), on plain IOS, this would be very simple:

ip nat inside source static 10.0.0.4 12.34.56.78

or, with port forwarding:

ip nat inside source static tcp 10.0.0.4 80 12.34.56.78 80

Please give it a try.

Best regards,
Peter

New Member

Thanks very much for the

Thanks very much for the clarification Peter!

That worked great.

Krista

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