If you don't understand this, then you are perhaps lacking some knowledge as to how HTTP redirects work, and/or how DNS lookups work, and/or how they are quite different concepts.

HTTP has redirects. DNS doesn't - but sure, it can be intercepted / hijacked.

> It's that time again got to read the man page

No need for the snark, this is HN, not Reddit.

But I'm already well aware of the feature you describe (after all, PiHole/similar relies on exactly this kind of interception) — but it isn't actually new at all, dnsmasq has had this since the the very beginning, literally day one.

It's still not redirection like HTTP though, it's interception: serving an IP number from a conf file when a matching domain is requested instead of querying upstream. Very similar to adding an entry in your local hosts file.

Redirect isn't a term that is really ever used in DNS configuration. Except in the context of NXDOMAIN responses. And that's certainly not the topic of this thread.

With HTTP redirection, the server responds with 'moved' and the URL of the new location of the requested content. But all one can do with DNS requests, is to respond: this is the IP for the domain A/CNAME you requested (or respond no-such-domain). In HTTP, that kind of inline interception can only be done with a proxy (transparent or otherwise) — and that's not the same as a the HTTP redirect mechanism at all.

Some folk might argue that this is only a semantic difference. But it's not at all: they're quite different mechanisms, different traffic-flow / communication patterns. And the distinction is quite important to anyone who manages both DNS and HTTP, at a certain level.

But if you want to call it DNS redirection, then good for you. But the old-timers will call it out nearly every time, because it's not actually redirection. — DNS doesn't have redirection like HTTP. Not in the same sense as HTTP at all. Anyone who claims otherwise, really just needs to brush up on their DNS knowledge / terminology.

HTH

That's the first time such a thing has been mentioned in this thread.

But I now get what you're trying to say in your comment above.

Sure, one can use e.g. iptables, to forward all outbound traffic on some port to some local IP. If your router has such capabilities.

But your rules won't be as simple as forward all port 53 traffic: you'll need to ensure that you exclude the PiHole from any rules like that (otherwise it would create an infinite loop) - or ensure the rule is specific for the device(s) in question.

And of course it wouldn't work if the device is using DoH.

But the issue you've introduced here, a device with hard-coded DNS, isn't really what this thread is about — the topic here was ~about wanting to group clients in PiHole, and different ways to configure the router to achieve this, without only seeing a single requesting client IP at the PiHole.