DNS · EUZOS

What is it?

DNS (dns) is a server package of EUZOS Server: it gives names to the devices on your network, without help from the router, and sends every other name on to the router. It listens on UDP and TCP 53, for the LAN only. The design is in docs/PACKAGE-DNS.md.

This version does not validate DNSSEC and has no DoH.

How do I…?

How do I turn it on?

In Server Admin, tab Packages: Set up at DNS. That opens the firewall for the LAN. Turning it off closes it again; the names stay in \EOS\FW\DNS.TXT.

How do I add a name?

Tab DNS, first tab DNS names: every name is listed there (name, type, value, TTL, and whether the name belongs to a website). Create DNS name opens a pop-in: name (nas) and address (<lan-address>). A name without a dot lands in your zone: <internal-host>. The pop-in says right away what is wrong.

Click a name to edit it: another address, or Remove (with a question first). The server answers A records (IPv4) only, with a TTL of 60 s.

The second tab Status and settings shows the rest: listening, the zones, where other names go, the counters.

A website you add with + New website as a LAN site gets its name by itself if the package is on; the reply says so. Removing the website leaves the name.

Where do other names go?

To the router, unless you change it under Other names go to: router, or addresses separated by commas.

How do I make the devices on the network use it?

In your router's DHCP settings, give the address of this server as DNS server. First reserve that address for this server in the router, otherwise it can change. Leave the router's own (WAN) DNS as it is.

How do I test it?

From any device on the network: dig @<lan-address> <internal-host>.

What can go wrong?

The server is off: devices that only know this DNS server find no names at all, not even on the internet, until the server is back.
A second DNS server in the router: devices may ask that one first, and then local names fail now and then.
The router's WAN DNS points at this server: a loop; every external name fails.
A device got another address: the name still points at the old one. There is no link with DHCP yet.

Limits

1024 names, 8 addresses per name, IPv4 only, no wildcards. 100 queries per second per device; above that a device gets no answer for a moment.