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Comment by akritid | Hacker News Reader

It’s called split DNS. Can be implemented using dnsmasq

It can be implemented with dnsmasq but dnsmasq doesn't integrate with DHCP (edit, client) out of the box and requires a restart to apply configuration updates which invalidates query cache.

Edit-

I think split dns more commonly refers to serving different internal/private and external/public zones.

In this case, the DNS servers may return the same results but if I'm connecting to a VPN running some distance away, I don't want to route all DNS requests to that server--only the ones for domains on that network. The Domains directive allows configuring this https://man.archlinux.org/man/systemd.network.5#%5BNETWORK%5...

You can add a dhclient hook to reconfigure dnsmasq with `server=` directives to achieve the same thing, but, as mentioned, that still requires restarting the dnsmasq daemon. That usually manifests as: the VPN connection times out, the hook runs, dnsmasq is restarted, but a random web page or request will fail while the daemon is restarting. Sure, you could do SO_REUSEADDR or something to prevent the disruption, but, once again, this all just works out of the box with systemd-*

> dnsmasq doesn't integrate with DHCP

DNSMasq is a combined DNS and DHCP server! Of course it's integrated!

I'm talking about a local caching resolver, not a server running somewhere else on the network. dnsmasq doesn't ship with a DHCP client

I don't get your point. DNSMasq doesn't ship with a client, because it's a server. It's a cacheing resolver and a DHCP server that is usually run locally. I don't know of any system that doesn't come with its own built-in (or standard) DHCP client.

Can you clarify your objection to DNSMasq?

His objection is that it doesn't replace the use case that resolvd is supposed to solve. Which is to provide a local service that can redirect DNS queries dynamically as local interfaces go up and down, which is where the integration with a DHCP client comes in.

Oh, OK. Thanks.

Makes sense; a lot of the systemd ecosphere seems to be about hotdesking, plugging things in and unplugging them, moving from one wifi AP to another, hibernating and so on. I don't encounter these use-cases, on the whole, which is probably a large part of why I find systemd so annoying.

Yeah, and I have some sympathies with what systemd is trying to do here, but the implementation is often backwards and/or half-arsed.

Still no DHCPRELEASE.

Dnsmasq and resolvd is a beast to tame in homelab, and split network.

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