avahi-daemon and ".local" domain issues

I have a **Ubuntu 16.04** based HTPC/Media Server that's running **24/7**. As far as I can remember using an official Ubuntu distro, I've always had issues with the **avahi-daemon**. The issue is pretty often discussed online. Some people decide to just delete daemon, however, I actually need it as I'm running a CUPS server and use Kodi as my AirPlay reciever. The issue --------- > **mDNS/DNS-SD is inherently incompatible with unicast DNS zones .local**. We strongly recommend not to use Avahi or ​nss-mdns in such a network setup. N.B.: nss-mdns is not typically bundled with Avahi and requires a separate download and install. (avahi.org) The symptoms are simple - after around 2-4 days of uptime the **network connection will go down** and this will be logged Mar 17 18:33:27 15 avahi-daemon: Withdrawing address record for 192.168.1.200 on enp3s0. Mar 17 18:33:27 15 avahi-daemon: Leaving mDNS multicast group on interface enp3s0.IPv4 with address 192.168.1.200. Mar 17 18:33:27 15 avahi-daemon: Interface enp3s0.IPv4 no longer relevant for mDNS. The **network will go back up** without issues **if you physically reconnect** the Ethernet plug, or if you reconnect software-side. Possible solutions ------------------ There are three solutions listed on the official wiki, which has been non-functional since what appears to be *June 2016*, so I'm providing a non-direct *archive.org* link 1.) Edit **/etc/nsswitch.conf** from "hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4" to hosts: files dns mdns4 2.) Modify **/etc/avahi/avahi-daemon.conf** from domain-name=.local to domain-name=alocal 3.) *"Ask the administrator to move the .local zone"* (as said on the wiki) ## What I did ## The **first solution** did not appear to work for me - the daemon still works, however, the **network will go down the same way as before** (to be fair, on the wiki it *does say* "**Y**our **M**ileage **M**ay **V**ary") The **second solution** causes the daemon to seemingly function properly (nothing wrong if you look at the logs) but the **iOS devices fail to "see" the machine** as a printer or an AirPlay reciever (as well as iTunes on my Windows machine) The **third solution** is tricky, because I'm not well versed in the *"ins and outs"* of how a network is functioning; and I'm not sure I actually tried it. Here's what I mean: on my **Asus Router** running Asuswrt-Merlin I went into a settings subcategory /LAN/DHCP Server/Basic Config. There I set "**RT-AC68U's Domain Name**" as "lan" (a domain name I saw advised on the web, because it doesn't conflict with anything, unlike "local"). As far as I can understand, that's what "**moving the .local zone**" means. If this is in fact correct, than this solution does not work for me as well. ## Conclusion ## So, what should I do? I've been battling with this problem for over 4 months now, and every answer online comes down to the those I've already tried; frankly, I'm completely lost. Thanks in advance!