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标题: centos7.6 网卡无法启动起来 [打印本页]

作者: 郑全 时间: 2019-8-10 10:33
标题: centos7.6 网卡无法启动起来
本帖最后由郑全于 2019-8-10 10:39 编辑

一天，发现网卡无法启动，使用 ip a,发现如下：

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
link/ether 00:0c:29:cf:d4:74 brd ff:ff:ff:ff:ff:ff

[root@dbserver ~]# 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 50599  bytes 23044797 (21.9 MiB)
      RX errors 0  dropped 0  overruns 0  frame 0
      TX packets 50599  bytes 23044797 (21.9 MiB)
      TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

说明网卡ens33没有用到

[root@dbserver ~]# nmcli con
NAME UUID                               TYPE    DEVICE
ens33  c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  --
[root@dbserver ~]# nmcli dev
DEVICE  TYPE    STATE    CONNECTION
ens33 ethernet  unmanaged  --
lo    loopback  unmanaged  --
[root@dbserver ~]# nmcli con up ens33
Error: Connection activation failed: No suitable device found for this connection.

重启NetworkManager服务，依然没有用

针对这个问题，可以使用network服务处理

但network需要配置文件中，加上网卡得mac地址，否则也起不来。

[root@dbserver network-scripts]# cat ifcfg-ens33
TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_PRIVACY=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME="ens33"
ONBOOT=yes
HWADDR=00:0C:29:CF:D4:74
IPADDR=192.168.133.120
NETMASK=255.255.255.0
GATEWAY=192.168.133.2
DNS1=192.168.133.2

之后，service network restart，后，网卡可以起来

ifconfig

[root@dbserver network-scripts]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
      inet 192.168.133.120  netmask 255.255.255.0  broadcast 192.168.133.255
      inet6 fe80::a0dc:d6c7:92d:7e62  prefixlen 64  scopeid 0x20<link>
      ether 00:0c:29:cf:d4:74  txqueuelen 1000  (Ethernet)
      RX packets 494  bytes 51822 (50.6 KiB)
      RX errors 0  dropped 0  overruns 0  frame 0
      TX packets 301  bytes 52510 (51.2 KiB)
      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 99613  bytes 46845295 (44.6 MiB)
      RX errors 0  dropped 0  overruns 0  frame 0
      TX packets 99613  bytes 46845295 (44.6 MiB)
      TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

但nmcli con之类的无法使用。

后来我始终觉得有问题，当时出现这个问题之前，是我更新了内核版本，但当时出现了一些问题，可能与这个有关，

更新之前为：
3.10.0-957.21.3.el7

更新之后，为以下版本27.2

[root@dbserver network-scripts]# uname -r
3.10.0-957.27.2.el7.x86_64

我后来重新更新这个版本，网卡还是不出来，
后来我发现一个问题：

[root@dbserver ~]# systemctl status NetworkManager
● NetworkManager.service - Network Manager
Loaded: loaded (/usr/lib/systemd/system/NetworkManager.service; disabled; vendor preset: enabled)
Active: active (running) since Sat 2019-08-10 09:48:43 CST; 1s ago
   Docs: man:NetworkManager(8)
Main PID: 4265 (NetworkManager)
CGroup: /system.slice/NetworkManager.service
         └─4265 /usr/sbin/NetworkManager --no-daemon
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4037] manager: Networking is disabled by state file
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4038] dhcp-init: Using DHCP client 'dhclient'
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4354] Loaded device plugin: NMWifiFactory (/usr/lib64/NetworkManager/1.12.0-10.el7_6/libnm-device-plugin-wifi.so)
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4430] Loaded device plugin: NMAtmManager (/usr/lib64/NetworkManager/1.12.0-10.el7_6/libnm-device-plugin-adsl.so)
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4588] Loaded device plugin: NMTeamFactory (/usr/lib64/NetworkManager/1.12.0-10.el7_6/libnm-device-plugin-team.so)
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4594] device (lo): carrier: link connected
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4603] manager: (lo): new Generic device (/org/freedesktop/NetworkManager/Devices/1)
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4609] device (ens33): carrier: link connected
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4612] manager: (ens33): new Ethernet device (/org/freedesktop/NetworkManager/Devices/2)
Aug 10 09:48:43 dbserver NetworkManager[4265]: <info>  [1565401723.4900] manager: startup complete

发现红色部分，但下次再去执行status，就没有这一行了，我通过网上搜索，没有看到centos,rhel有类似的问题，倒是看到有一个ubuntu有这样的问题，具体连接如下：

http://www.ubuntugeek.com/how-to ... tu-10-04-lucid.html

原文内容如下：

If your network manager is not working, and says unmanaged, or Networking disabled in ubuntu 10.04 try this fix
Open the terminal from Applications menu -> Accessories -> Terminal run the following commands

service network-manager stop
rm /var/lib/NetworkManager/NetworkManager.state
service network-manager start

Then reboot your system.

难道centos7.6也有这样的问题吗，
我在我机器上搜了一下，确实有这个文件。
[root@dbserver network-scripts]# find / -name NetworkManager.state
/var/lib/NetworkManager/NetworkManager.state

[root@dbserver network-scripts]# cat /var/lib/NetworkManager/NetworkManager.state
[main]
NetworkingEnabled=false
WirelessEnabled=true
WWANEnabled=true

发现这里 NetworkingEnabled=false ，我修改为true，重新启动NetworkManager，还是不行，

我把这个文件移走，重新再去重启NetworkManager，神奇发现了，网卡可以正常使用了,同时，又会自动产生这个文件，而且这个文件 NetworkingEnabled=true了。

[root@dbserver network-scripts]# nmcli con
NAME UUID                               TYPE    DEVICE
ens33  c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33
[root@dbserver network-scripts]# nmcli dev
DEVICE  TYPE    STATE    CONNECTION
ens33 ethernet  connected  ens33
lo    loopback  unmanaged  --
[root@dbserver network-scripts]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
      inet 192.168.133.120  netmask 255.255.255.0  broadcast 192.168.133.255
      inet6 fe80::a0dc:d6c7:92d:7e62  prefixlen 64  scopeid 0x20<link>
      ether 00:0c:29:cf:d4:74  txqueuelen 1000  (Ethernet)
      RX packets 869  bytes 90795 (88.6 KiB)
      RX errors 0  dropped 0  overruns 0  frame 0
      TX packets 548  bytes 90046 (87.9 KiB)
      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 124712  bytes 56428208 (53.8 MiB)
      RX errors 0  dropped 0  overruns 0  frame 0
      TX packets 124712  bytes 56428208 (53.8 MiB)
      TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

再重启机器，都没有问题。

最后，我无法确定是否是升级kernel，后面有空的时候，再重现一下，只是这里要提一个醒，因为我发现很多人的系统是直接连接到外网的，如果遇到了这个问题，怎么处理。

附：
我的环境：
centos 7.6
[root@dbserver network-scripts]# yum list kernel
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
* base: mirror.jdcloud.com
* extras: mirrors.163.com
* updates: mirror.jdcloud.com
Installed Packages
kernel.x86_64                                                                                           3.10.0-957.el7                                                                                                 @anaconda
kernel.x86_64                                                                                           3.10.0-957.21.3.el7                                                                                           @updates
kernel.x86_64                                                                                           3.10.0-957.27.2.el7                                                                                           @updates
[root@dbserver network-scripts]#

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