Eu tenho experimentado uma situação semelhante muitas vezes durante os anos. Agora eu tenho duas máquinas se comportando dessa maneira. Depois de clonar as máquinas virtuais do Kubuntu, o gerenciador de rede do KDE não mostra nenhuma interface. Ifconfig retorna isso:
luca@ubuntu:~$ ifconfig
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 344 bytes 22272 (22.2 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 344 bytes 22272 (22.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
luca@ubuntu:~$ ifconfig -a
ens33: flags=4098<BROADCAST,MULTICAST> mtu 1500
ether 00:50:56:39:57:9e txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 424 bytes 27072 (27.0 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 424 bytes 27072 (27.0 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Eu tentei muitas soluções possíveis, mas nenhuma funcionou. Estes são os logs que encontrei relacionados ao gerenciador de rede, mas não entendo claramente o que o erro significa exatamente:
luca@ubuntu:~$ sudo journalctl -u NetworkManager.service
[sudo] password for luca:
-- Logs begin at Sun 2018-05-06 06:38:15 PDT, end at Sun 2018-05-06 06:43:20 PDT. --
May 06 06:38:15 ubuntu systemd[1]: Starting Network Manager...
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1426] NetworkManager (version 1.8.4) is starting... (for the first time)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1427] Read config: /etc/NetworkManager/NetworkManager.conf (lib: 10-dns-resolved.conf) (run: 10-globally-managed-devices.conf) (etc:
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1650] manager[0x55e5ace78040]: monitoring kernel firmware directory '/lib/firmware'.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1654] monitoring ifupdown state file '/run/network/ifstate'.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1663] policy: hostname management mode: default
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1670] dns-mgr[0x55e5ace86150]: init: dns=systemd-resolved, rc-manager=symlink, plugin=systemd-resolved
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.1698] manager[0x55e5ace78040]: NetworkManager state is now ASLEEP
May 06 06:38:16 ubuntu systemd[1]: Started Network Manager.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3233] init!
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3239] interface-parser: parsing file /etc/network/interfaces
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3240] interface-parser: finished parsing file /etc/network/interfaces
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3242] guessed connection type (ens33) = 802-3-ethernet
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3243] update_connection_setting_from_if_block: name:ens33, type:802-3-ethernet, id:Ifupdown (ens33), uuid: 108b861f-800d-98ce-9ab4-4e
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3244] adding ens33 to connections
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3244] adding iface ens33 to eni_ifaces
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3244] autoconnect
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3244] management mode: managed
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] devices added (path: /sys/devices/pci0000:00/0000:00:11.0/0000:02:01.0/net/ens33, iface: ens33)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] locking wired connection setting
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] devices added (path: /sys/devices/virtual/net/lo, iface: lo)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] device added (path: /sys/devices/virtual/net/lo, iface: lo): no ifupdown configuration found.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] end _init.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3247] settings: loaded plugin ifupdown: (C) 2008 Canonical Ltd. To report bugs please use the NetworkManager mailing list. (/usr/lib
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3248] settings: loaded plugin keyfile: (c) 2007 - 2016 Red Hat, Inc. To report bugs please use the NetworkManager mailing list.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3248] (-1393870080) ... get_connections.
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.3248] (-1393870080) connections count: 1
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5204] settings: hostname: using hostnamed
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5205] settings: hostname changed from (none) to "ubuntu"
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5310] dhcp-init: Using DHCP client 'dhclient'
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5311] manager: rfkill: WiFi enabled by radio killswitch; enabled by state file
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5311] manager: rfkill: WWAN enabled by radio killswitch; enabled by state file
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5311] manager: Networking is disabled by state file
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5334] Loaded device plugin: NMBondDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5334] Loaded device plugin: NMBridgeDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5334] Loaded device plugin: NMDummyDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5335] Loaded device plugin: NMEthernetDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5335] Loaded device plugin: NMInfinibandDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5335] Loaded device plugin: NMIPTunnelDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5335] Loaded device plugin: NMMacsecDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5336] Loaded device plugin: NMMacvlanDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5338] Loaded device plugin: NMTunDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5339] Loaded device plugin: NMVethDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5339] Loaded device plugin: NMVlanDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5339] Loaded device plugin: NMVxlanDeviceFactory (internal)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5725] Loaded device plugin: NMAtmManager (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-adsl.so)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5738] Loaded device plugin: NMWwanFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-wwan.so)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5768] Loaded device plugin: NMBluezManager (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-bluetooth.so)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5787] Loaded device plugin: NMWifiFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/libnm-device-plugin-wifi.so)
May 06 06:38:16 ubuntu NetworkManager[506]: ((src/devices/nm-device.c:1452)): assertion '<dropped>' failed
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5811] device (lo): link connected
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5826] manager: (lo): new Generic device (/org/freedesktop/NetworkManager/Devices/1)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5888] manager: (ens33): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
May 06 06:38:16 ubuntu NetworkManager[506]: <warn> [1525613896.5911] Error: failed to open /run/network/ifstate
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5977] devices added (path: /sys/devices/pci0000:00/0000:00:11.0/0000:02:01.0/net/ens33, iface: ens33)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.5988] locking wired connection setting
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.6024] urfkill disappeared from the bus
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.6093] ModemManager available in the bus
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.6101] manager: startup complete
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.8028] devices added (path: /sys/devices/virtual/net/lo, iface: lo)
May 06 06:38:16 ubuntu NetworkManager[506]: <info> [1525613896.8028] device added (path: /sys/devices/virtual/net/lo, iface: lo): no ifupdown configuration found.
May 06 06:38:26 ubuntu NetworkManager[506]: <info> [1525613906.4225] manager: rfkill: WiFi hardware radio set enabled
May 06 06:38:26 ubuntu NetworkManager[506]: <info> [1525613906.4226] manager: rfkill: WWAN hardware radio set enabled
Alguma ideia de como corrigir esta situação?