Ubuntu20.04 有线网络图标消失解决方案

问题描述： ubuntu20.04系统提示的software updater有软件包更新，按提示安装更新软件包，重启系统后，ubuntu系统的网络图标消失不见；无法正常上网；检查网口，发现网卡上的灯也不亮；在系统Settings的Network项中，网络配置项也不见了，无法配置网络参数。

原因：这个是Ubuntu Network Manager Bug

解决方案：

sudo lshw -c Network命令测试问题：

$ sudo lshw -c Network
  *-network:0               
       description: Wireless interface
       product: Cannon Point-LP CNVi [Wireless-AC]
       vendor: Intel Corporation
       physical id: 14.3
       bus info: pci@0000:00:14.3
       logical name: wlp0s20f3
       version: 30
       serial: 38:00:25:9b:44:2a
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=5.13.0-51-generic firmware=46.4d093a30.0 9000-pu-b0-jf-b0- ip=192.168.1.104 latency=0 link=yes multicast=yes wireless=IEEE 802.11
       resources: irq:16 memory:c9738000-c973bfff
  *-network:1 DISABLED
       description: Ethernet interface
       product: Ethernet Connection (6) I219-V
       vendor: Intel Corporation
       physical id: 1f.6
       bus info: pci@0000:00:1f.6
       logical name: enp0s31f6
       version: 30
       serial: 98:fa:9b:12:3e:10
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.13.0-51-generic firmware=0.5-3 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:167 memory:c9700000-c971ffff
  *-network DISABLED
       description: Ethernet interface
       physical id: 2
       bus info: usb@1:4
       logical name: enx00e04f0000ce
       serial: 00:e0:4f:00:00:ce
       size: 100Mbit/s
       capacity: 1Gbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.12.12 duplex=full firmware=rtl8153a-4 v2 02/07/20 link=no multicast=yes port=MII speed=100Mbit/s

可见 Ethernet interface 状态为 DISABLE ，可以创建一个缺少的配置文件进而解决这个问题，具体操作如下：

sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo systemctl restart NetworkManager

之后，继续用lshw命令测试结果如下：

$ sudo lshw -c Network
  *-network:0 DISABLED      
       description: Wireless interface
       product: Cannon Point-LP CNVi [Wireless-AC]
       vendor: Intel Corporation
       physical id: 14.3
       bus info: pci@0000:00:14.3
       logical name: wlp0s20f3
       version: 30
       serial: 38:00:25:9b:44:2a
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wireless
       configuration: broadcast=yes driver=iwlwifi driverversion=5.13.0-51-generic firmware=46.4d093a30.0 9000-pu-b0-jf-b0- latency=0 link=no multicast=yes wireless=IEEE 802.11
       resources: irq:16 memory:c9738000-c973bfff
  *-network:1
       description: Ethernet interface
       product: Ethernet Connection (6) I219-V
       vendor: Intel Corporation
       physical id: 1f.6
       bus info: pci@0000:00:1f.6
       logical name: enp0s31f6
       version: 30
       serial: 98:fa:9b:12:3e:10
       capacity: 1Gbit/s
       width: 32 bits
       clock: 33MHz
       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.13.0-51-generic firmware=0.5-3 latency=0 link=no multicast=yes port=twisted pair
       resources: irq:167 memory:c9700000-c971ffff
  *-network
       description: Ethernet interface
       physical id: 2
       bus info: usb@1:4
       logical name: enx00e04f0000ce
       serial: 00:e0:4f:00:00:ce
       size: 100Mbit/s
       capacity: 1Gbit/s
       capabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=r8152 driverversion=v1.12.12 duplex=full firmware=rtl8153a-4 v2 02/07/20 ip=192.168.1.105 link=yes multicast=yes port=MII speed=100Mbit/s

可以看到physical id: 2的网卡已经恢复正常，同时网络图标也恢复正常可见。

以上是我的电脑网络修复的方案

其他方案参考：

在处理这个问题的过程中还看到有其他方案，但可能我电脑的状态不太一样，经过尝试并没有处理掉； 但如果有遇到网络图标消失的情况，也可进行尝试：

1、删除NetworkManager的缓存

$ sudo service NetworkManager stop 

$ sudo rm /var/lib/NetworkManager/NetworkManager.state 

$ sudo service NetworkManager start

2、修改配置，把其中的manage=false改为true

sudo vi /etc/NetworkManager/NetworkManager.conf

3、重启NetworkManager

sudo service NetworkManager restart

参考文章：https://blog.csdn.net/weixin_46721287/article/details/126098278