I would chime in a bit on this too. 14.04 _did_ have such issues. In fact, I had a physical box with static IP's (2 nics), if a cable was unpligged, it would hang forever and also become inconsistent. I had these discussions a year ago or so. Anyway, I had ot abandon ubuntu server (along with some nft issues at the time) and run archlinux as my xen host.
But I ran zfs as my xen backend, so on arch, I sometimes* could have issues ~ once a year where it best be I had physical access to the box to be able to fix any potential issues. I am now going to move abroad and so I thought , with archlinux unpriv. lxc containers out, to leave xen (as I don't have the expected network output from the servers) to lxc. With arch and benig abroad, I think ubuntu 16.04 now with systemd would have solved this (my server with arch on xen has always gracefully sorted it out: ~1.5-2 years). Seeing this bug and seein git has to do with ifup makes me think it's partly a remnance from the older logic from sysv/upstart. This probably doesn't help much butjust saying the ifup is a bit archaic now that systemd is in use and is not evebn present in archlinux and creates seemingly less problems. I have only a brief moment before leaving so seeing this now worries me. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to ifupdown in Ubuntu. https://bugs.launchpad.net/bugs/1588915 Title: ifup does not block for interface to be up with static addresses Status in ifupdown package in Ubuntu: Confirmed Bug description: Description: Ubuntu 16.04 LTS (server) Release: 16.04 systemd: Installed: 229-4ubuntu6 Candidate: 229-4ubuntu6 Version table: *** 229-4ubuntu6 500 500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 100 /var/lib/dpkg/status 229-4ubuntu4 500 500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages This issue is more about systemd integration then an issue with systemd package itself. The general problem is the distinction between the network being configured and the network being up and what that means for services that depend on the network. upstream systemd has network.target (network is configured) and network-online.target (network is up), however xenial server (dunno about desktop) doesn't seem to use network-online.target. The result of which is, as soon as the network is configured both network.target and network-online.target are considered complete. At which point services dependent on either of those will get started. However this can lead to problems if the services in question are actually dependent on the network (ie dns lookups) when they are starting up. Here's an example of what I mean. If you install openntpd and add the -s option there is a race on boot if it will or wont be able to do the initial sync. Jun 02 16:58:02 xenial64 systemd[1]: Reached target Network. Jun 02 16:58:02 xenial64 systemd[1]: Starting OpenNTPd Network Time Protocol... Jun 02 16:58:02 xenial64 systemd[1]: Reached target Network is Online. Jun 02 16:58:02 xenial64 ntpd[920]: constraint certificate verification turned off Jun 02 16:58:02 xenial64 ntpd[928]: ntp engine ready Jun 02 16:58:02 xenial64 kernel: tg3 0000:02:00.0 enp2s0: Link is down Jun 02 16:58:05 xenial64 kernel: tg3 0000:02:00.0 enp2s0: Link is up at 1000 Mbps, full duplex Jun 02 16:58:05 xenial64 kernel: tg3 0000:02:00.0 enp2s0: Flow control is on for TX and on for RX Jun 02 16:58:05 xenial64 kernel: IPv6: ADDRCONF(NETDEV_CHANGE): enp2s0: link becomes ready Jun 02 16:58:17 xenial64 ntpd[920]: no reply received in time, skipping initial time setting openntpd was started 3 seconds before the interface even got link. I believe this issue is only going to effect physical servers with static ips. vm's interfaces will instantly have link when they are brought up and dhcp, the interface will already be up or else they wouldn't have been able to get an ip. thanks jim To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/1588915/+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
