[SOLVED] IP address substitution

[bongosmoker]

Hey. Is it possible to somehow substitute a destination IP address to a different one? In more details: I have a small network with few boxes, and a Linux router. I want to create a situation where every request from some box inside the network to the local address 192.168.0.113 will be redirected to external IP 80.50.50.50 (a DNS server) and the data obtained from 80.50.50.50 will be passed to the local IP which requested the connection with 192.168.0.113.

I don't think I have any other option. Right now I got another computer that I want to connect to the network, but I can't change the parameters of its IP configuration (the laptop must work in it's original network environment as well), and it has a fixed DNS address of 192.168.0.113. If only I could somehow force the 192.168.0.113 address to be seen as "80.50.50.50" in the network, the connection should work. Pinging IPs (even external ones) is working, only DNS resolving isn't. It is a Windows box btw.

Or maybe there is another way to do it (not counting using VMWare to create a bridged host that will have an ip of 192.168.0.113 which will forward DNS requests to 80.50.50.50)?

[John R. Graham]

You could put another NIC in one of your computers, assign that NIC the fixed IP address 192.168.0.113, and then run a DNS proxy like "dnsmasq" to forward DNS requests on to your real DNS.[/list] Kind of messy, but not expensive.

- John

[bongosmoker]

That would fix the problem I suppose, but I was hoping to find some answer without adding new hardware, maybe some iptables rules or spoofing softs , this solution will be only a temporary one, so it doesn't need to be elegant, it just needs to work. I'll buy a new NIC as a fallback, if everything else will fail. Thanks for the dnsmasq hint

[Hu]

What is the layout of your internal network? You might be able to get away with assigning your existing internal NIC a second address, if it is on the right subnet. See ip addr add for details.

[Beju]

[bongosmoker]