After upgrading from Ubuntu 14.04 to 16.04 I'm experiencing random network failures. The syslog and only shows where named stops listening and logging in at the console then restarting the networking service fixes the issue.
Can anyone provide some insight on how to better trouble shoot this? This Ubuntu server 16.04 box is running DNS, Apache, Samba, and Pro-FTPD. Pretty basic setup really but since the upgrade the network has become very unreliable.
System is running in a VMware ESX virtual machine.
Here is a where it stops responding to network requests in the syslog:
Sep 2 17:52:11 pyrite named[3133]: no IPv6 interfaces found
Sep 2 17:52:11 pyrite named[3133]: no longer listening on 192.168.0.1#53
Sep 2 17:52:11 pyrite avahi-daemon[2849]: Withdrawing address record for 192.168.0.1 on ens33.
Sep 2 17:52:11 pyrite avahi-daemon[2849]: Leaving mDNS multicast group on interface ens33.IPv4 with address 192.168.0.1.
Sep 2 17:52:11 pyrite avahi-daemon[2849]: Interface ens33.IPv4 no longer relevant for mDNS.
Sep 2 17:52:12 pyrite whoopsie[2937]: [17:52:12] Cannot reach: https://daisy.ubuntu.com
Sep 2 17:55:25 pyrite kernel: [364408.500113] nfs: server 192.168.0.4 not responding, timed out
Contents of /etc/network/interfaces:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The primary network interface
auto eth0
iface eth0 init dhcp
ifconfig output (when network is working):
ens33 Link encap:Ethernet HWaddr 00:0c:29:4f:39:93
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:27522144 errors:0 dropped:0 overruns:0 frame:0
TX packets:66067215 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:17797538322 (17.7 GB) TX bytes:143204036336 (143.2 GB)
Can anyone explain with "eth0" isn't showing up and instead I'm getting "ens33"? Not sure that this matters but it doesn't seem correct to me either. I don't believe it was showing up like this in Ubuntu 14.04 prior to upgrading to 16.04.
My problem is very similar to the one posted here but even after several updates my system is still randomly requiring the network restarted.
I'm currently looking into the avahi-daemon configuration but I don't see anything incorrect on this system. The "local" resolver stuff is commented out in the default configuration my system is running. Is there a good guide for configuring avahi-daemon?
Edit - adding this here in case someone else stumbles on my question regarding the network not being eth0 ( Why is my network interface named enp0s25 instead of eth0? ). Looks like this is a system issue. Still don't have any info other than avahi-daemon potentially causing the networking service issue.