23.centos 7配置网络

1.ifconfig：查看网卡信息

如果centos7 最小化安装没有ifconfig这个命令，可以使用yum install net-tools 来安装。

centos7 网卡命名规则：
en： ethernet以太网卡
o：主板集成网卡
p：PCI独立网卡
s：热插拔网卡
nnn数字：MAC+主板信息（生产唯一序号）

如：ifcfg-ens33 （以太热插拔）

[root@centos ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.10.64.77  netmask 255.255.248.0  broadcast 10.10.71.255
        inet6 fe80::db93:c1b1:674d:47e8  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:77:ea:f1  txqueuelen 1000  (Ethernet)
        RX packets 1712270  bytes 1140094109 (1.0 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 212453  bytes 15689873 (14.9 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

UP：网卡开启状态
RUNNING：网线连接状态
MULTICAST：支持组播
mut 1500：最大传输单元1500字节
inet：IP地址
netmask：子网掩码
broadcast：广播地址
ether：MAC地址
RX packets：发送包信息
RX error：发送错误信息
TX packets：接收包信息
TX error：接收错误信息

systemctl restart network：重启网络服务

systemctl status network/network.serivce：查看网络服务

[root@centos ~]# systemctl status network
● network.service - LSB: Bring up/down networking
   Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled)
   Active: active (exited) since Fri 2020-08-28 13:27:00 CST; 1min 56s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 39958 ExecStop=/etc/rc.d/init.d/network stop (code=exited, status=0/SUCCESS)
  Process: 40123 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=0/SUCCESS)

Aug 28 13:27:00 centos systemd[1]: Starting LSB: Bring up/down networking...
Aug 28 13:27:00 centos network[40123]: Bringing up loopback interface:  [  OK  ]
Aug 28 13:27:00 centos network[40123]: Bringing up interface ens33:  Connection successfully.../5)
Aug 28 13:27:00 centos network[40123]: [  OK  ]
Aug 28 13:27:00 centos systemd[1]: Started LSB: Bring up/down networking.
Hint: Some lines were ellipsized, use -l to show in full.

网络服务守护进程： NetworkManager

systemctl status NetworkManager：查看网络守护进程状态：

网卡配置文件：/etc/sysconfig/network-scripts/ifcfg-ens33

DNS配置文件:/etc/resolv.conf

2.配置或修改IP的两种方式

1）使用命令nmtui，菜单方式修改

2）修改网卡配置文件

[root@centos ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens33 

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=static
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
IPV6_ADDR_GEN_MODE=stable-privacy
NAME=ens33
UUID=9780a5a8-a7e8-4a17-86b1-cf68aab1ca87
DEVICE=ens33
ONBOOT=yes
IPADDR=192.168.137.133
NETMASK=255.255.255.0
GATEWAY=192.168.137.1
DNS1=192.168.137.1
ZONE=external