Destination NAT on Cisco 876?

Question

Imagine the following scenario:

10.0.0.1/24 .254 |-----------+ dyn. IP +-------+-----------+ Cisco 876 +--------- Internet (PPPoE) | | |-----------+ | | Host 1 Host2 .1 .2

The Problem:

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Host 1 should be reachable from the Internet over port 22. Since the outside IP Adress of the Cisco 876 is allocated dynamically, it registers this address at dyndns.org. And so far, everything's working fine. The problem occurs if Host2 tries to connect to Host1 by using its DynDNS-Name (which resolves to the outside IP address of the 876), the SSH connection takes place with the 876 and NOT with Host1. Is there any known possibility to get that working?

I thought of something like dnat on the PIX, which translates destination adresses, but I did not manage it yet.

TIA, Martin

Igor Mamuzic · Accepted Answer

Please post your NAT config...B.R.Igor

Alni · Answer

Bonjour,Martin Turba avait prétendu :I've exactly the same problem...(and did'nt found any issue yet)

Uli Link · Answer

Can be done via route-map and a loopback interface.Set a different next-hop interface according to the source interface to circumvent NAT.

Alni · Answer

Bonjour,Uli Link vient de nous annoncer :Any config example ?

Martin Turba · Answer

Thanks, Uli.. I'll try that in our lab next week. If I am successful, I'll post a configuration example here.Martin

Erik Tamminga · Answer

Something like this: ?ip nat inside source static tcp 10.0.0.1 22 interface [outside-if-name-here] 22 extendableBe sure to disable ssh on the 876 itself and any access lists permit port 22 from the internet.(crypto key zeroize rsa, to disable ssh)erik

Destination NAT on Cisco 876?

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