宁波专业优化网站制作公司整站优化系统厂家

突然打开ubuntu虚拟机，发现连不上网，输入ifconfig发现ens33是关闭的状态。

systemd中的NetworkManager管理着系统的网络服务，使用：

systemctl status NetworkManager

查看服务状态是显示运行的。

查看systemd的启动日志：

journalctl -u NetworkManager -b

显示如下：

3月 18 14:40:13 oushaojun-virtual-machine systemd[1]: Starting Network Manager...
3月 18 14:40:13 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280013.9544] NetworkManager (version 1.36.4) is starting... (for the first time)
3月 18 14:40:13 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280013.9545] Read config: /etc/NetworkManager/NetworkManager.conf (lib: 10-dns-resolved.conf, 20-conn>
3月 18 14:40:13 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280013.9659] bus-manager: acquired D-Bus service "org.freedesktop.NetworkManager"
3月 18 14:40:13 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280013.9843] manager[0x646607e8b000]: monitoring kernel firmware directory '/lib/firmware'.
3月 18 14:40:13 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280013.9844] monitoring ifupdown state file '/run/network/ifstate'.
3月 18 14:40:14 oushaojun-virtual-machine systemd[1]: Started Network Manager.
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6798] hostname: hostname: using hostnamed
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6798] hostname: static hostname changed from (none) to "oushaojun-virtual-machine"
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6808] dns-mgr[0x646607e692a0]: init: dns=systemd-resolved rc-manager=unmanaged (auto), plugin=>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6816] manager[0x646607e8b000]: rfkill: Wi-Fi hardware radio set enabled
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6816] manager[0x646607e8b000]: rfkill: WWAN hardware radio set enabled
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6977] Loaded device plugin: NMBluezManager (/usr/lib/x86_64-linux-gnu/NetworkManager/1.36.4/li>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.6986] Loaded device plugin: NMWifiFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.36.4/lib>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7011] Loaded device plugin: NMAtmManager (/usr/lib/x86_64-linux-gnu/NetworkManager/1.36.4/libn>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7016] Loaded device plugin: NMWwanFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.36.4/lib>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7028] Loaded device plugin: NMTeamFactory (/usr/lib/x86_64-linux-gnu/NetworkManager/1.36.4/lib>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7029] manager: rfkill: Wi-Fi enabled by radio killswitch; enabled by state file
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7029] manager: rfkill: WWAN enabled by radio killswitch; enabled by state file
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7029] manager: Networking is disabled by state file
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7038] settings: Loaded settings plugin: ifupdown ("/usr/lib/x86_64-linux-gnu/NetworkManager/1.>
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7039] settings: Loaded settings plugin: keyfile (internal)
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7039] ifupdown: management mode: unmanaged
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7040] ifupdown: interfaces file /etc/network/interfaces doesn't exist
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7101] dhcp-init: Using DHCP client 'internal'
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7101] device (lo): carrier: link connected
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7102] manager: (lo): new Generic device (/org/freedesktop/NetworkManager/Devices/1)
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7107] manager: (ens33): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7127] failed to open /run/network/ifstate
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7179] manager: startup complete
3月 18 14:40:14 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280014.7232] modem-manager: ModemManager available
3月 18 14:40:16 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280016.9136] agent-manager: agent[e8756b322ffe013d,:1.38/org.gnome.Shell.NetworkAgent/127]: agent reg>
3月 18 14:40:24 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280024.2382] agent-manager: agent[d1307b92a00c44af,:1.79/org.gnome.Shell.NetworkAgent/1000]: agent re>
3月 18 14:44:05 oushaojun-virtual-machine systemd[1]: Stopping Network Manager...
3月 18 14:44:05 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280245.0572] caught SIGTERM, shutting down normally.
3月 18 14:44:05 oushaojun-virtual-machine NetworkManager[776]: <info>  [1742280245.0623] exiting (success)
3月 18 14:44:05 oushaojun-virtual-machine systemd[1]: NetworkManager.service: Deactivated successfully.
3月 18 14:44:05 oushaojun-virtual-machine systemd[1]: Stopped Network Manager.
3月 18 14:44:05 oushaojun-virtual-machine systemd[1]: Starting Network Manager...

 看到关键信息：

Networking is disabled by state file

 使用nmcli工具可以管理NetworkManager:

sudo nmcli networking on

此处主要是打开了NetworkManager的一个全局开关，允许管理所有网络设备，存储位置为：/var/lib/NetworkManager/NetworkManager.state，内容应为：

[main]
NetworkingEnabled=true   # 或 false

 

同时确认/etc/NetworkManager/NetworkManager.conf中内容为如下：

[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=true   # 允许 NetworkManager 接管传统 ifupdown 接口

 同时确认/etc/netplan/*.yaml中内容为：

network:
  version: 2
  renderer: NetworkManager

 然后重启NetworkManager服务即可：

sudo systemctl restart NetworkManager