mDNS and Avahi: Local Service Discovery That Works Until It Doesn't

Wed, 03 Jul 2024 16:00:00 +0000

You have done this a hundred times without thinking about it. You plug a Raspberry Pi into the network, type ssh pi@raspberrypi.local, and it just works — no DNS server, no editing /etc/hosts, no looking up an IP that DHCP hands out semi-randomly. That .local resolution is multicast DNS (mDNS), and on Linux the daemon doing the heavy lifting is almost always Avahi. It is genuinely brilliant when it works, and genuinely maddening on the days it doesn’t, mostly because nobody ever explains what it’s actually doing.

Avahi - Tag - vo.rs

mDNS and Avahi: Local Service Discovery That Works Until It Doesn't