Setup avahi-daemon on Ubuntu for so you can reach hostname `ubuntu.local` from host OS

setup-avahi.sh

sudo apt-get install avahi-daemon avahi-discover avahi-utils libnss-mdns mdns-scan

Glad I stumbled on this. avahi-daemon alone worked for me on Ubuntu Server 20.04.3 LTS. I could even log in to Virtualmin/Webmin's control panel using the hostname after adding a rule for the mdns service in firewalld.

Thank you.

I'm not sure what's wrong on my Ubuntu system. avahi-browse -a shows my five local mDNS devices on the network by their host names. However, if I try avahi-resolve-host-name on any one of them it gives me a "Timeout reached". I'm unable to ping any of them. I've installed everything described in this thread, and I've tried the various settings. The behavior remains unchanged. Any thoughts what I may be missing?

Try the hostname without the ".local". I have an Octopi server (its a 3D printer appliance) on a Raspberry Pi and sometimes octopi.local works and sometimes just octopi. Not sure why. Then I just recently installed Avahi on a virtual machine and no matter what I did hostname.local didn't work. Then I tried hostname by itself without a .local and viola! SSH and web browser can both reach it that way.

May I suggest the following as an all-in-one? sudo apt update && sudo apt-get install avahi-daemon avahi-discover avahi-utils libnss-mdns mdns-scan && sudo apt upgrade. Once that looks good, sudo reboot. That got me going on my new Ubuntu install on the TuringPi RK-1 modules.

I looked them up to know what each one does.
avahi-daemon is the core service on your device that makes it publish itself via mDNS. This is the only thing you need to make your device respond to {hostname}.local. It seems like it can also advertise other services on the network through mDNS though, but I'm not sure.

avahi-discover is a GUI app to show other services published through mDNS. I didn't need it.
mdns-scan is a CLI that also scans for mDNS services on the local network. Useful for troubleshooting, but I also didn't need it.
avahi-utils is a collection of CLI tools that could be useful, but I didn't need them for my server. It includes things like avahi-browse which is similar to the above two tools.

libnss-mdns is useful for client devices that want to access services published via mDNS. So if you want your device to reach other .local services, you need this installed.