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New Member

Forward Public to Private IP


I have cisco 837 Router with ADSL connection with fixed Public IP and one LAN IP The LAN interface is connected to a LAN Switch where an application server is also connected.

Is it possible to forward the telnet traffic hitting the public ip of the ADSL Router to private IP automatically without asking the users any user name and password for telnet?

I need to allow this only traffic coming for one public ip and not the whole internet.

Example: A user having the public ip telnets to the public ip of the ADSL Router. The Router should see if the traffic is coming from the allowed public IP and then automatically forward that traffic to


Hall of Fame Super Gold

Re: Forward Public to Private IP

Yes, the only problem is that if forward telnet you will not be able to telnet to the router itself. So it's recommended that you use a different external port eg:

ip nat inside source static tcp 23 interface dialer0 230

Alternatively you've to disable telnet to the router so to use 23 as external port.

Hope this helps, please rate post if it does!

New Member

Re: Forward Public to Private IP

Thanks! Will try.