I spend a bit of time debugging this with xnox. Here some of the results: # How to reproduce: I setup a isc-dhcp-server with a fixed IP for my test rpi2 set to default/max lifetime of 120sec. The rpi2 was connected to the network with the isc-dhcp-server but unmodified otherwise. Once the pi2 connected and got an IP I switched the default IP to +1 and reloaded the isc-dhcp-server configuration. When the lease expired I could see the same as the OP - i.e. both IPs got removed.
# Related upstream bugs: The patch from https://github.com/systemd/systemd/issues/5625 did not help with the issue # Log The full log of systemd-networkd is available here: http://paste.ubuntu.com/25686225/ - it was obtained by adding [Service]\nEnvironment=SYSTEMD_LOG_LEVEL=debug for the systemd-networkd.service. The relevant lines: Mar 14 21:02:52 localhost.localdomain systemd-networkd[7660]: eth0: Adding address: 192.168.1.124/24 (valid for 2min) Mar 14 21:02:52 localhost.localdomain systemd-networkd[7660]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/network1/link/_33 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=16 reply_cookie=0 error=n/a Mar 14 21:02:52 localhost.localdomain systemd-networkd[7660]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/network1 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=17 reply_cookie=0 error=n/a Mar 14 21:02:52 localhost.localdomain systemd-timesyncd[995]: Network configuration changed, trying to establish connection. Mar 14 21:02:52 localhost.localdomain systemd[1]: Starting Update resolvconf for networkd DNS... Mar 14 21:02:56 localhost.localdomain systemd-networkd[7660]: NDISC: Sent Router Solicitation Mar 14 21:03:00 localhost.localdomain systemd-networkd[7660]: NDISC: Sent Router Solicitation Mar 14 21:03:04 localhost.localdomain systemd-networkd[7660]: NDISC: Invoking callback for 't'. Mar 14 21:03:22 localhost.localdomain systemd[1]: Started Update resolvconf for networkd DNS. Mar 14 21:03:51 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x22f0fd4b): REQUEST (renewing) Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x22f0fd4b): REQUEST (rebinding) Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x22f0fd4b): NAK: requested address is incorrect Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): REBOOT in 0 Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): DISCOVER Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): OFFER Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): REQUEST (requesting) Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): ACK Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): lease expires in 1min 57s Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): T2 expires in 1min 43s Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: DHCP CLIENT (0x4d15b90b): T1 expires in 1min Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: eth0: DHCPv4 address 192.168.1.125/24 Mar 14 21:04:36 localhost.localdomain systemd-timesyncd[995]: Network configuration changed, trying to establish connection. Mar 14 21:04:36 localhost.localdomain systemd-networkd[7660]: eth0: Updating address: 192.168.1.125/24 (valid for 2min) Mar 14 21:04:36 localhost.localdomain systemd[1]: Starting Update resolvconf for networkd DNS... Mar 14 21:04:52 localhost.localdomain systemd-networkd[7660]: eth0: Removing address: 192.168.1.125/24 (valid for 1min 44s) Mar 14 21:04:52 localhost.localdomain systemd-networkd[7660]: eth0: Removing address: 192.168.1.124/24 (valid for 0) Mar 14 21:04:52 localhost.localdomain systemd-networkd[7660]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/network1/link/_33 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=18 reply_cookie=0 error=n/a Mar 14 21:04:52 localhost.localdomain systemd-networkd[7660]: Sent message type=signal sender=n/a destination=n/a object=/org/freedesktop/network1 interface=org.freedesktop.DBus.Properties member=PropertiesChanged cookie=19 reply_cookie=0 error=n/a Mar 14 21:04:52 localhost.localdomain systemd-timesyncd[995]: Network configuration changed, trying to establish connection. Mar 14 21:05:06 localhost.localdomain systemd[1]: Started Update resolvconf for networkd DNS. ** Bug watch added: github.com/systemd/systemd/issues #5625 https://github.com/systemd/systemd/issues/5625 -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1721223 Title: Networkd fail to set ip address between leases if ip address changes on UbuntuCore Status in Snappy: New Status in systemd package in Ubuntu: New Status in systemd source package in Xenial: New Bug description: Hi there, we found a replicable issue that involves the Ubuntu Core networking and causes complete loss of connectivity. We run a custom board with ubuntu core: the architecure is amrhf. We replicated this issue with an official Ubuntu Core image on a Raspberry Pi: other platform was been tested. It shows that it is a snap core problem which interests networkd: we use the default network stack based on networkd + netplan. Below steps to replicate the issue. 1)Setup a dhcp server for lease of about some minutes (i.e 10 minutes). 2)Boot the board and wait for get an ip from dhcp server 3)Before the lease expires, set a reservation for a different ip address Depending on lease duration before the lease expires( for 10 minute we have 2 minutes before ), networkd configure the new address in addition to the previous one. When the lease expire both ip address ( the prevoius and the new one ) disappear from the interested network interface. Depending on lease duration before the second lease expires ( for 10 minure we have 2 minutes before ) networkd configure only the new ip address on the network interface and the ping toward an outside host work properly. During the test the dhcp server records correctly leases and their duration. We check directly from console the network interface setting with the tool ip, checking continuously the value for ip address and valid_lft fields for the interested network interface. Please note that if the ip address setting are the same between leases the problem doesn’t jump out. Please note that if the ip address setting are different between lease the problem jumps out and it is very bad: Typically the lease time on consumer router are about some day, then a board that change ip between lease loses the network connectivity for some day without a direct action. Please, after a confirmation from your side of the issue, could you fix the problem or escalate the issue at the upstream project? We are available for further testing. Below syslog annotated with ip address state: Oct 4 09:48:06 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:49:36 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:49:25 localhost systemd-timesyncd[996]: Network configuration changed, trying to establish connection. Oct 4 09:49:26 localhost systemd-timesyncd[996]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com). Oct 4 09:49:26 localhost systemd[1]: Starting Update resolvconf for networkd DNS... Oct 4 09:49:26 localhost systemd[1]: Started Update resolvconf for networkd DNS. Oct 4 09:49:37 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:51:07 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:51:09 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:52:39 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:52:40 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:54:10 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:54:11 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:55:41 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:54:23 localhost systemd-timesyncd[996]: Network configuration changed, trying to establish connection. Oct 4 09:54:23 localhost systemd[1]: Starting Update resolvconf for networkd DNS... Oct 4 09:54:23 localhost systemd-timesyncd[996]: Synchronized to time server 91.189.89.199:123 (ntp.ubuntu.com). Oct 4 09:54:23 localhost systemd[1]: Started Update resolvconf for networkd DNS. Oct 4 09:55:43 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:57:13 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:57:14 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 09:58:44 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 09:58:46 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:00:16 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:00:17 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:01:47 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:01:48 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:03:18 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:03:05 localhost systemd-networkd[623]: eth0: DHCPv4 address 192.168.5.124/24 via 192.168.5.1 -----> here begin two ip address state Oct 4 10:03:05 localhost systemd-timesyncd[996]: Network configuration changed, trying to establish connection. Oct 4 10:03:05 localhost systemd[1]: Starting Update resolvconf for networkd DNS... Oct 4 10:03:05 localhost systemd[1]: Started Update resolvconf for networkd DNS. Oct 4 10:03:15 localhost systemd-timesyncd[996]: Timed out waiting for reply from 91.189.89.199:123 (ntp.ubuntu.com). Oct 4 10:03:16 localhost systemd-timesyncd[996]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com). Oct 4 10:03:20 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:04:50 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:04:23 localhost systemd-timesyncd[996]: Network configuration changed, trying to establish connection. ----> disappear any address Oct 4 10:04:23 localhost systemd[1]: Starting Update resolvconf for networkd DNS... Oct 4 10:04:23 localhost systemd[1]: Started Update resolvconf for networkd DNS. Oct 4 10:04:51 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:06:21 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:06:23 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:07:53 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:07:54 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:09:24 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:09:24 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:10:54 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:10:55 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:12:25 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] ------> before this line interface eth0 don't have address, after this line the interfaces get 192.168.5.124/24( the second lise adddress) Oct 4 10:11:49 localhost systemd[1]: Starting Update resolvconf for networkd DNS... Oct 4 10:11:49 localhost systemd[1]: Started Update resolvconf for networkd DNS. Oct 4 10:12:25 localhost rsyslogd-2007: action 'action 11' suspended, next retry is Wed Oct 4 10:13:55 2017 [v8.16.0 try http://www.rsyslog.com/e/2007 ] Oct 4 10:13:18 localhost systemd[1]: Started Session 23 of user domotz. Cheers, Nicolino To manage notifications about this bug go to: https://bugs.launchpad.net/snappy/+bug/1721223/+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