[Bug 1696415] [NEW] NetworkManager does not update IPv4 address lifetime even though DHCP lease was successfully renewed

Launchpad Bug Tracker 1696415 at bugs.launchpad.net
Wed Nov 8 21:09:39 UTC 2017


You have been subscribed to a public bug by Ray Link (rlink):

I've found an issue on some of our Xenial office machines, causing
NetworkManager to drop its IP address lease in some cases when it
shouldn't. I'm not sure if the actual bug is in NetworkManager or
perhaps dbus or dhclient, but I'll do my best to help to figure out
where it is.

What appears to happen:
* NetworkManager is informed of a new IPv4 lease.
* During the lease, dhclient keeps it fresh by renewing it using DHCPREQUESTs regularly.
* In spite of this, NetworkManager drops the IP address from the interface when the last reported lease time expires.

This happens on various machines, once every few days. We are using a
failover DHCP configuration using two machines (192.168.0.3 'bonaire'
and 192.168.0.4 'curacao').



The machine where I've done the debugging is called 'pampus'
(192.168.0.166). As you can see in the logs, at 01:21:06 NetworkManager
reports a new lease with lease time 7200.

jun 07 01:21:06 pampus dhclient[1532]: DHCPREQUEST of 192.168.0.166 on eth0 to 192.168.0.4 port 67 (xid=0x3295b440)
jun 07 01:21:06 pampus dhclient[1532]: DHCPACK of 192.168.0.166 from 192.168.0.4
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   address 192.168.0.166
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   plen 24 (255.255.255.0)
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   gateway 192.168.0.5
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   server identifier 192.168.0.4
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   lease time 7200
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   nameserver '192.168.0.3'
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   nameserver '192.168.0.4'
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9530]   domain name 'office.screenpointmed.com'
jun 07 01:21:06 pampus NetworkManager[1161]: <info>  [1496791266.9531] dhcp4 (eth0): state changed bound -> bound

After this, dhclient is supposed to keep the lease fresh, which it does.
E.g. at 03:13:19 you can see a DHCPREQUEST and DHCPACK; I've seen this
DHCPACK in a tcpdump and it contains a new lease time of 7200 seconds.

jun 07 03:13:19 pampus dhclient[1532]: DHCPREQUEST of 192.168.0.166 on eth0 to 192.168.0.4 port 67 (xid=0x3295b440)
jun 07 03:13:19 pampus dhclient[1532]: DHCPACK of 192.168.0.166 from 192.168.0.4
jun 07 03:13:19 pampus dhclient[1532]: bound to 192.168.0.166 -- renewal in 2708 seconds.

However, at 03:21:07 (exactly 2 hours and 1 second after the last lease
reported by NetworkManager) Avahi and NTP report that the IP address is
gone:

jun 07 03:21:07 pampus avahi-daemon[1167]: Withdrawing address record for 192.168.0.166 on eth0.
jun 07 03:21:07 pampus avahi-daemon[1167]: Leaving mDNS multicast group on interface eth0.IPv4 with address 192.168.0.166.
jun 07 03:21:07 pampus avahi-daemon[1167]: Interface eth0.IPv4 no longer relevant for mDNS.
jun 07 03:21:08 pampus ntpd[18832]: Deleting interface #3 eth0, 192.168.0.166#123, interface stats: received=2512, sent=2549, dropped=0, active_time=111819 secs

So I suspect NetworkManager dropped the IP address from the interface,
because it wasn't informed by dhclient that the lease was renewed. The
logs don't explicitly say this, so I may have to turn on more verbose
debugging logs in NetworkManager or dhclient to verify this.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: network-manager 1.2.6-0ubuntu0.16.04.1
ProcVersionSignature: Ubuntu 4.4.0-66.87-generic 4.4.44
Uname: Linux 4.4.0-66-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.6
Architecture: amd64
Date: Wed Jun  7 14:48:59 2017
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2016-11-04 (214 days ago)
InstallationMedia: Ubuntu 14.04.5 LTS "Trusty Tahr" - Release amd64 (20160803)
IpRoute:
 default via 192.168.0.5 dev eth0  proto static  metric 100 
 192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.166 
 192.168.0.0/24 dev eth0  proto kernel  scope link  src 192.168.0.166  metric 100
IwConfig:
 lo        no wireless extensions.
 
 eth1      no wireless extensions.
 
 eth0      no wireless extensions.
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
RfKill:
 
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME                UUID                                  TYPE            TIMESTAMP   TIMESTAMP-REAL                AUTOCONNECT  AUTOCONNECT-PRIORITY  READONLY  DBUS-PATH                                   ACTIVE  DEVICE  STATE      ACTIVE-PATH                                        
 Wired connection 1  37da1802-e1ce-3326-a6d0-f855cc32806d  802-3-ethernet  1496839466  wo 07 jun 2017 14:44:26 CEST  yes          4294966297            no        /org/freedesktop/NetworkManager/Settings/0  yes     eth0    activated  /org/freedesktop/NetworkManager/ActiveConnection/0 
 Wired connection 2  a040d7fe-3c52-39ba-82b8-50fad0b602c1  802-3-ethernet  1496399665  vr 02 jun 2017 12:34:25 CEST  yes          4294966297            no        /org/freedesktop/NetworkManager/Settings/1  no      --      --         --
nmcli-dev:
 DEVICE  TYPE      STATE        DBUS-PATH                                  CONNECTION          CON-UUID                              CON-PATH                                           
 eth0    ethernet  connected    /org/freedesktop/NetworkManager/Devices/0  Wired connection 1  37da1802-e1ce-3326-a6d0-f855cc32806d  /org/freedesktop/NetworkManager/ActiveConnection/0 
 eth1    ethernet  unavailable  /org/freedesktop/NetworkManager/Devices/2  --                  --                                    --                                                 
 lo      loopback  unmanaged    /org/freedesktop/NetworkManager/Devices/1  --                  --                                    --
nmcli-nm:
 RUNNING  VERSION  STATE      STARTUP  CONNECTIVITY  NETWORKING  WIFI-HW  WIFI     WWAN-HW  WWAN    
 running  1.2.6    connected  started  full          enabled     enabled  enabled  enabled  enabled

** Affects: network-manager
     Importance: Medium
         Status: Confirmed

** Affects: network-manager (Ubuntu)
     Importance: Low
         Status: Confirmed


** Tags: amd64 apport-bug third-party-packages xenial
-- 
NetworkManager does not update IPv4 address lifetime even though DHCP lease was successfully renewed
https://bugs.launchpad.net/bugs/1696415
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