Routes from DHCP not respected

[Michał Sawicz]

After upgrading to artful a while ago, my system no longer respects routes given out by my DHCP:

 tail -f /var/log/syslog | grep -i dhcp
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0380] dhcp4 (enx0123456789ab): activation: beginning transaction (timeout in 45 seconds)
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0446] dhcp4 (enx0123456789ab): dhclient started with pid 23633
Aug 1 17:07:43 user-laptop dhclient[23633]: DHCPREQUEST of 10.2.0.5 on enx0123456789ab to 255.255.255.255 port 67 (xid=0x13152178)
Aug 1 17:07:43 user-laptop dhclient[23633]: DHCPACK of 10.2.0.5 from 10.2.0.1
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0805] dhcp4 (enx0123456789ab): address 10.2.0.5
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0805] dhcp4 (enx0123456789ab): plen 24 (255.255.255.0)
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0805] dhcp4 (enx0123456789ab): classless static route 10.0.0.0/13 gw 10.2.0.1
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): gateway 10.2.0.253
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): lease time 86400
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): hostname 'user-laptop'
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): nameserver '10.2.0.1'
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): domain name 'user.domain'
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp (enx0123456789ab): domain search 'user.domain.'
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp (enx0123456789ab): domain search 'domain.'
Aug 1 17:07:43 user-laptop NetworkManager[2627]: <info> [1501600063.0806] dhcp4 (enx0123456789ab): state changed unknown -> bound
^C
 ip route
default via 10.2.0.253 dev enx0123456789ab proto static metric 100
10.2.0.0/24 dev enx0123456789ab proto kernel scope link src 10.2.0.5 metric 102

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: network-manager 1.8.2-1ubuntu2
ProcVersionSignature: Ubuntu 4.11.0-10.15-generic 4.11.8
Uname: Linux 4.11.0-10-generic x86_64
NonfreeKernelModules: zfs zunicode zavl zcommon znvpair
ApportVersion: 2.20.6-0ubuntu4
Architecture: amd64
CurrentDesktop: GNOME
Date: Tue Aug 1 17:08:24 2017
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2016-05-06 (451 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
NetworkManager.conf:
 [main]
 plugins=ifupdown,keyfile

 [ifupdown]
 managed=false
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=false
 WWANEnabled=true
SourcePackage: network-manager
UpgradeStatus: Upgraded to artful on 2017-07-19 (13 days ago)
modified.conffile..etc.polkit-1.localauthority.50-local.d.org.freedesktop.NetworkManager.pkla: [deleted]
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.8.2 connected started full enabled enabled disabled enabled enabled