Due to a lack of failures it has been a while since I last wrote, but I think I may have found a possible cause of the problem. Confirmation from other sources would be necessary, of course.
For the previous participants, and anyone else who lands here, I think that the failure may go like this:- - a network problem prevents reception of a D.H.C.P. lease offer from the server - NetworkManager starts a new D.H.C.P. client thread, but the old thread is still active and the lease has not expired - these two steps may be repeated several times, starting several D.H.C.P. threads, with identical or different addresses, possibly receiving and transmitting traffic - some time (possibly hours) later, another instance of the client has leased the address, the original client's lease expires - avahi surrenders the address; the host has lost its network connection In my case, some months earlier, it became apparent that the D.H.C.P. server was connected to a network switch port that was occasionally dropping packets - hence errors were reported for the server's and client's network adaptors. The packet retry count and network load increased. I changed the physical network arrangement and there were no more failures - until I switched off the server for maintenance. Here is a test which might support this theory. Note that the server was not available between 05:38 and 07:17 on 2018-01-24. The client's network connection was not lost until 2018-01-30. [LinuxMint] graham@yoyo $ ps -ef | grep -v "grep" | grep -e "PID" -e "dhc" UID PID PPID C STIME TTY TIME CMD root 2444 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 3327 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 4550 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 5070 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 6094 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 6616 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 7605 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 8179 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 9152 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 9442 1 0 Jan24 ? 00:00:00 /sbin/dhclient -v eth0 root 21279 11291 0 03:26 ? 00:00:00 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /var/run/dhclient-eth0.pid -lf /var/lib/NetworkManager/dhclient-3339a4b3-ef0a-3db1-acf1-9b810d040dfe-eth0.lease -cf /var/lib/NetworkManager/dhclient-eth0.conf eth0 Tue Jan 30 08:38:33 ~ The start times of those dhclient instances were:- 05:50 05:55 06:05 06:11 06:21 06:27 06:37 06:43 06:53 06:59. The log server had many instances of exchanges between kevin the server and yoyo the client like this:- 2018-01-30T07:25:11+00:00 kevin dhcpd[3612]: DHCPREQUEST for 192.168.42.187 from 00:25:64:72:72:14 via enp0s19 2018-01-30T07:25:11+00:00 kevin dhcpd[3612]: DHCPACK on 192.168.42.187 to 00:25:64:72:72:14 via enp0s19 2018-01-30T07:25:17+00:00 yoyo dhclient[2444]: DHCPREQUEST of 192.168.42.161 on eth0 to 192.168.42.129 port 67 (xid=0x182b3059) 2018-01-30T07:25:17+00:00 kevin dhcpd[3612]: reuse_lease: lease age 306 (secs) under 25% threshold, reply with unaltered, existing lease for 192.168.42.161 2018-01-30T07:25:17+00:00 kevin dhcpd[3612]: DHCPREQUEST for 192.168.42.161 from 00:25:64:72:72:14 via enp0s19 2018-01-30T07:25:17+00:00 kevin dhcpd[3612]: DHCPACK on 192.168.42.161 to 00:25:64:72:72:14 via enp0s19 2018-01-30T07:25:18+00:00 yoyo dhclient[8179]: DHCPREQUEST of 192.168.42.162 on eth0 to 255.255.255.255 port 67 (xid=0x537943a) 2018-01-30T07:25:18+00:00 kevin dhcpd[3612]: reuse_lease: lease age 4397 (secs) under 25% threshold, reply with unaltered, existing lease for 192.168.42.162 I have tried to be brief in this report, but I can provide more information if anyone wants it. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1586528 Title: Avahi-daemon withdraws address record To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1586528/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
