network status is connected despite no connection

[Bartosz Woronicz]

it seems that the Network Manager persist in connected state, despite actually there's no connection.

$ nmcli general
STATE CONNECTIVITY WIFI-HW WIFI WWAN-HW WWAN
connected (local only) full enabled enabled enabled enabled

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp0s25: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 3c:97:0e:1f:ce:f7 brd ff:ff:ff:ff:ff:ff
3: wlp3s0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 60:67:20:39:d2:40 brd ff:ff:ff:ff:ff:ff
4: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:c7:8b:0a:ef brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: network-manager 1.0.4-0ubuntu5.2
ProcVersionSignature: Ubuntu 4.2.0-27.32-generic 4.2.8-ckt1
Uname: Linux 4.2.0-27-generic x86_64
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Feb 14 00:13:00 2016
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2015-05-20 (269 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
IpRoute:
 default via 192.168.32.254 dev wlp3s0 proto static metric 600
 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
 192.168.32.0/24 dev wlp3s0 proto kernel scope link src 192.168.32.114 metric 600
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager
UpgradeStatus: Upgraded to wily on 2015-10-22 (114 days ago)
modified.conffile..etc.NetworkManager.dispatcher.d.01ifupdown: [deleted]
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 docker0 bridge connected /org/freedesktop/NetworkManager/Devices/3 docker0 5074208b-4ac4-4b18-84dd-b126526de8d9 /org/freedesktop/NetworkManager/ActiveConnection/0
 wlp3s0 wifi connected /org/freedesktop/NetworkManager/Devices/2 zwirek 208e8615-1fe8-40c4-b351-008977265099 /org/freedesktop/NetworkManager/ActiveConnection/1
 enp0s25 ethernet unavailable /org/freedesktop/NetworkManager/Devices/0 -- -- --
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/1 -- -- --
nmcli-nm: Error: command ['nmcli', '-f', 'all', 'nm'] failed with exit code 2: Error: Object 'nm' is unknown, try 'nmcli help'.