Same symptoms, same result on a headless always-on box running 16.04. Made worse by the fact that I have to hard-power off the box and hook it up to monitor for troubleshooting. Every couple weeks the machine will lose connection to the network.
Last time I thought I lost the on-board NIC and went and bought/installed a new NIC card (another Realtek). Two weeks later, same result: syslog shows this:
May 24 22:40:14 phaedrus avahi-daemon[857]: Withdrawing address record for 192.168.0.201 on enp4s1.
May 24 22:40:14 phaedrus avahi-daemon[857]: Leaving mDNS multicast group on interface enp4s1.IPv4 with address 192.168.0.201.
May 24 22:40:14 phaedrus avahi-daemon[857]: Interface enp4s1.IPv4 no longer relevant for mDNS.
Same symptoms, same result on a headless always-on box running 16.04. Made worse by the fact that I have to hard-power off the box and hook it up to monitor for troubleshooting. Every couple weeks the machine will lose connection to the network.
Last time I thought I lost the on-board NIC and went and bought/installed a new NIC card (another Realtek). Two weeks later, same result: syslog shows this:
May 24 22:40:14 phaedrus avahi-daemon[857]: Withdrawing address record for 192.168.0.201 on enp4s1.
May 24 22:40:14 phaedrus avahi-daemon[857]: Leaving mDNS multicast group on interface enp4s1.IPv4 with address 192.168.0.201.
May 24 22:40:14 phaedrus avahi-daemon[857]: Interface enp4s1.IPv4 no longer relevant for mDNS.
## System:
Host: phaedrus Kernel: 4.4.0-78-generic x86_64 (64 bit) Console: tty 9 Distro: Ubuntu 16.04 xenial
## Network: (from `inxi -F`)
Card-1: Device 000c:d051
IF: N/A state: N/A speed: N/A duplex: N/A mac: N/A
Card-2: Realtek RTL8169 PCI Gigabit Ethernet Controller driver: r8169
IF: enp4s1 state: up speed: 1000 Mbps duplex: full mac: 00:0a:cd:2c:93:5f
Looks like it might be Realtek 8168/9 related?