This has been happening to me lately. I am using 17.04. I have a feeling it might be IPv6 related since we just started using that at work, so it's only affecting me there. Usually I see the following in my syslog:
> Sep 5 15:40:46 laptop avahi-daemon[1158]: Withdrawing address record for > 1234:5678:4556::99 on eth0. > Sep 5 15:40:46 laptop avahi-daemon[1158]: Leaving mDNS multicast group on > interface eth0.IPv6 with address 1234:5678:4556::99. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1586528 Title: Avahi-daemon withdraws address record Status in avahi package in Ubuntu: Confirmed Status in network-manager package in Ubuntu: Confirmed Bug description: For some reason, if I leave my Ubuntu VM up for a prolonged period of time the machine will lose connection to the network. ip addr shows that the nic port no longer has an address and an examination of the syslog shows this: May 27 14:19:38 matt-VirtualBox avahi-daemon[590]: Withdrawing address record for 10.0.2.15 on enp0s3. May 27 14:19:38 matt-VirtualBox avahi-daemon[590]: Leaving mDNS multicast group on interface enp0s3.IPv4 with address 10.0.2.15. May 27 14:19:38 matt-VirtualBox avahi-daemon[590]: Interface enp0s3.IPv4 no longer relevant for mDNS. for no known reason. The only reliable way to get the network to come back (that I have found) is a full reboot. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: avahi-daemon 0.6.32~rc+dfsg-1ubuntu2 ProcVersionSignature: Ubuntu 4.4.0-22.40-generic 4.4.8 Uname: Linux 4.4.0-22-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: Unity Date: Fri May 27 15:11:34 2016 InstallationDate: Installed on 2015-10-22 (218 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) SourcePackage: avahi UpgradeStatus: Upgraded to xenial on 2016-03-30 (58 days ago) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1586528/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
