Ubuntu20.04 有線網絡圖標消失解決方案
問題描述： ubuntu20.04系統提示的software updater有軟件包更新，按提示安裝更新軟件包，重啟系統后，ubuntu系統的網絡圖標消失不見；無法正常上網；檢查網口，發現網卡上的燈也不亮；在系統Settings的Network項中，網絡配置項也不見了，無法配置網絡參數。
原因：這個是Ubuntu Network Manager Bug
解決方案：
sudo lshw -c Network命令測試問題：
$ sudo lshw -c Network*-network:0 description: Wireless interfaceproduct: Cannon Point-LP CNVi [Wireless-AC]vendor: Intel Corporationphysical id: 14.3bus info: pci@0000:00:14.3logical name: wlp0s20f3version: 30serial: 38:00:25:9b:44:2awidth: 64 bitsclock: 33MHzcapabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wirelessconfiguration: 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 802.11resources: irq:16 memory:c9738000-c973bfff*-network:1 DISABLEDdescription: Ethernet interfaceproduct: Ethernet Connection (6) I219-Vvendor: Intel Corporationphysical id: 1f.6bus info: pci@0000:00:1f.6logical name: enp0s31f6version: 30serial: 98:fa:9b:12:3e:10capacity: 1Gbit/swidth: 32 bitsclock: 33MHzcapabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiationconfiguration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.13.0-51-generic firmware=0.5-3 latency=0 link=no multicast=yes port=twisted pairresources: irq:167 memory:c9700000-c971ffff*-network DISABLEDdescription: Ethernet interfacephysical id: 2bus info: usb@1:4logical name: enx00e04f0000ceserial: 00:e0:4f:00:00:cesize: 100Mbit/scapacity: 1Gbit/scapabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiationconfiguration: 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
可見 Ethernet interface 狀態為 DISABLE ，可以創建一個缺少的配置文件進而解決這個問題，具體操作如下：
sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf
sudo systemctl restart NetworkManager之后，繼續用lshw命令測試結果如下：
$ sudo lshw -c Network*-network:0 DISABLED description: Wireless interfaceproduct: Cannon Point-LP CNVi [Wireless-AC]vendor: Intel Corporationphysical id: 14.3bus info: pci@0000:00:14.3logical name: wlp0s20f3version: 30serial: 38:00:25:9b:44:2awidth: 64 bitsclock: 33MHzcapabilities: pm msi pciexpress msix bus_master cap_list ethernet physical wirelessconfiguration: 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 802.11resources: irq:16 memory:c9738000-c973bfff*-network:1description: Ethernet interfaceproduct: Ethernet Connection (6) I219-Vvendor: Intel Corporationphysical id: 1f.6bus info: pci@0000:00:1f.6logical name: enp0s31f6version: 30serial: 98:fa:9b:12:3e:10capacity: 1Gbit/swidth: 32 bitsclock: 33MHzcapabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiationconfiguration: autonegotiation=on broadcast=yes driver=e1000e driverversion=5.13.0-51-generic firmware=0.5-3 latency=0 link=no multicast=yes port=twisted pairresources: irq:167 memory:c9700000-c971ffff*-networkdescription: Ethernet interfacephysical id: 2bus info: usb@1:4logical name: enx00e04f0000ceserial: 00:e0:4f:00:00:cesize: 100Mbit/scapacity: 1Gbit/scapabilities: ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiationconfiguration: 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的網卡已經恢復正常，同時網絡圖標也恢復正常可見。
以上是我的電腦網絡修復的方案
其他方案參考：
在處理這個問題的過程中還看到有其他方案，但可能我電腦的狀態不太一樣，經過嘗試并沒有處理掉； 但如果有遇到網絡圖標消失的情況，也可進行嘗試：
1、刪除NetworkManager的緩存
$ 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改為true
sudo vi /etc/NetworkManager/NetworkManager.conf3、重啟NetworkManager
sudo service NetworkManager restart參考文章：https://blog.csdn.net/weixin_46721287/article/details/126098278
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