avahi-daemon constantly registers/withdraws IPv6 address record

[Dan Ursu]

Running Ubuntu 17.04, have avahi-daemon 0.6.32-1ubuntu1 installed.

If I check syslog, every 5 - 10 seconds there is a set of messages like message like:

Jun 15 20:53:01 dan-pc avahi-daemon[6673]: Registering new address record for 2001:1970:5ea2:c101:a899:2dfa:5a35:61fd on enp0s31f6.*.
Jun 15 20:53:01 dan-pc avahi-daemon[6673]: Registering new address record for 2001:1970:5ea2:c101:64ee:d405:6df8:900a on enp0s31f6.*.
Jun 15 20:53:01 dan-pc avahi-daemon[6673]: Withdrawing address record for 2001:1970:5ea2:c101:64ee:d405:6df8:900a on enp0s31f6.
Jun 15 20:53:01 dan-pc avahi-daemon[6673]: Withdrawing address record for 2001:1970:5ea2:c101:a899:2dfa:5a35:61fd on enp0s31f6.

etc..., which is clearly not normal. (This was also tested on a brand new installation of Ubuntu 17.04, same issue). Attached is a small sample of my syslog file.

This also seems to impact other programs that use an ipv6 connection. For example, Google Chrome - half the time I try to load a webpage I get "your connection was interrupted; a network change was detected". After about a half-second, it proceeds to load the webpage, although often doesn't load it properly. This does not affect all websites (likely only those that support ipv6).

See https://askubuntu.com/questions/905866/new-ubuntu-17-04-problem-your-connection-was-interrupted for other people experiencing the same bug, both in avahi and Chrome.

Disabling ipv6 seems to work as a temporary workaround.

I am also not sure whether this bug is caused by avahi, or whether it is just experiencing the most "symptoms".

ProblemType: Bug
DistroRelease: Ubuntu 17.04
Package: avahi-daemon 0.6.32-1ubuntu1
ProcVersionSignature: Ubuntu 4.10.0-22.24-generic 4.10.15
Uname: Linux 4.10.0-22-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.4-0ubuntu4.1
Architecture: amd64
CurrentDesktop: X-Cinnamon
Date: Thu Jun 15 20:42:19 2017
InstallationDate: Installed on 2017-06-10 (5 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
SourcePackage: avahi
UpgradeStatus: No upgrade log present (probably fresh install)

[Trent Lloyd (lathiat)]

This is known upstream but not yet solved, working on it I have a theory

[Trent Lloyd (lathiat)]

https://github.com/lathiat/avahi/issues/41

[Chris Bainbridge (chris-bainbridge)]

On my network, tcpdump suggests this happened in response to the router sending an IPv6 router advertisement every few minutes, and was stopped after:

  ip6tables -A INPUT -p icmpv6 --icmpv6-type router-advertisement -j DROP