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Comment by _RPM | Hacker News Reader

How exactly would that work. modify an instance of bind and check if the client is requesting to resolve 'google.com'? If true, then respond with the rouge IP? First we must make sure the client machine is set up to use our name servers, the ones we have control over.

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You can just set up the zones in e.g. Your local network nameserver to say it's authoritative for google.com then send the traffic to wherever you want. Many companies do this on a large scale on their internal networks for the purpose of having easy-to-use names (that can have the nodes behind them changed out without changing anything else) using, mostly for backward-compatibility or legacy reasons, the same domains / zones that may resolve externally to different RRsets. This is known as split-horizon DNS: https://en.m.wikipedia.org/wiki/Split-horizon_DNS

Never use a rouge IP. They're red for a reason, man.

I'm glad someone else picked up on that! :)

You don't even need to setup the client, if you have control over any number of intermediate routers, you can snag/reroute port 53 tcp/udp traffic any way you like. I tend to setup my home router to do this, so that all open dns traffic goes where I tell it to.

It's also advised to do so for unauthenticated users on shared/public wifi so that you can provide an agreement page/site. Also, so that unauthenticated users can't use DNS as a tunnel method, which is pretty damned cool, but insecure.

I've set up my laptop to go to my home internal server (old laptop) for DNS. My quality-of-development-environment has increased because I can associate any internal in development app I want with a hostname tied to my internal DNS prefix. Very useful for setting up nginx for multiple applications.

You can do it locally with dnsmasq or using xip.io, without an extra server.

Also, so that unauthenticated users can't use DNS as a tunnel method, which is pretty damned cool, but insecure.

You can put TLS into a DNS tunnel too, it's just even slower.

I've done TCP-over-SSH-over-DNS many times (using iodine and sshuttle) and it was actually surprisingly usable! I could get over 200Kbps downstream. Iodine uses NULL requests -if allowed by the recursive DNS server- which can fit 1KB+ per request/reply.

You can do it by listening in promiscuous mode and injecting packets into the network pretending to be the DNS server.

You can also setup a rouge DHCP server that sends a different DNS address.

There are likewise many other methods.

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