linux网络相关

查看网卡 ifconfig/ip

[root@localhost ~]# ip addr
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 UP group default qlen 1000
    link/ether 00:0c:29:66:07:5c brd ff:ff:ff:ff:ff:ff
    inet 192.168.127.128/24 brd 192.168.127.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::d44c:c57b:11b7:9bd5/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
[root@localhost ~]# ifconfig  # 需要安装 net-tools
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.127.128  netmask 255.255.255.0  broadcast 192.168.127.255
        inet6 fe80::d44c:c57b:11b7:9bd5  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:66:07:5c  txqueuelen 1000  (Ethernet)
        RX packets 112  bytes 10870 (10.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 100  bytes 12449 (12.1 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 68  bytes 5920 (5.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 68  bytes 5920 (5.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

开启/关闭网卡

[root@localhost ~]# ifdown ens33 && ifup ens33
成功断开设备 'ens33'。
连接已成功激活（D-Bus 活动路径：/org/freedesktop/NetworkManager/ActiveConnection/2）

关闭网卡后会导致ssh不能访问，所以要 ifdown ens33 && ifup ens33

创建虚拟网卡

[root@localhost ~]# cd /etc/sysconfig/network-scripts/
[root@localhost network-scripts]# cp ifcfg-ens33 ifcfg-ens33\:0
cp：是否覆盖"ifcfg-ens33:0"？ y
[root@localhost network-scripts]# vim ifcfg-ens33\:0
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="ens33:0"
UUID="61d3f945-5a5a-403d-be81-a669df2f0d6b"
DEVICE="ens33:0"
ONBOOT="yes"
IPADDR="192.168.127.150"
NETMASK="255.255.255.0"
GATEWAY="192.168.127.2"                                                                              
[root@localhost network-scripts]# systemctl restart network
[root@localhost network-scripts]# ip addr
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 UP group default qlen 1000
    link/ether 00:0c:29:66:07:5c brd ff:ff:ff:ff:ff:ff
    inet 192.168.127.128/24 brd 192.168.127.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 192.168.127.150/24 brd 192.168.127.255 scope global secondary noprefixroute ens33:0
       valid_lft forever preferred_lft forever
    inet6 fe80::d44c:c57b:11b7:9bd5/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever

修改主机名

[root@localhost ~]# hostname ccc # 第一种
[root@localhost ~]# bash
[root@ccc ~]# hostnamectl set-hostname aaaa # 第二种
[root@ccc ~]# bash
[root@aaaa ~]# vim /etc/hostname  # 第三种
bbb                                                                                  
[root@aaaa ~]# reboot

配置DNS文件

[root@aaaa ~]# cat /etc/resolv.conf 
# Generated by NetworkManager
nameserver 114.114.114.114

系统域名文件

[root@aaaa ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

只在本机有效