查看網絡設備的狀態:

[root@rhce7 ~]# nmcli dev status 
DEVICE     TYPE              STATE       
ens32      802-3-ethernet    connected   
eth1       802-3-ethernet    disconnected
lo      loopback  unmanaged  --

[root@rhce7 ~]# nmcli dev disconnect ens32     #ens32是device名，不是connection名

[root@rhce7 ~]# nmcli dev connect ens32          #ens32是device名，不是connection名

[root@rhce7 ~]# nmcli con show
NAME   UUID                                  TYPE            DEVICE 
eth2   96238a53-4ffd-4358-aa73-15e7b7ae81c5  802-3-ethernet  --     
eth1   085c71ca-aac2-4851-a8a5-8e4f239e5e65  802-3-ethernet  --     
ens32  10d3aba6-f468-4b6e-b5a7-789c85811c09  802-3-ethernet  ens32  
eth3   1ae34078-53db-4453-bd93-ba7bc3adc1b6  802-3-ethernet  --   

[root@rhce7 ~]# nmcli con show --active
NAME   UUID                                  TYPE            DEVICE 
ens32  10d3aba6-f468-4b6e-b5a7-789c85811c09  802-3-ethernet  ens32  

[root@rhce7 ~]# nmcli con down eth1

[root@rhce7 ~]# nmcli con up eth1 #這里的eth1是connection名，不是device名

[root@rhce7 ~]# nmcli con mod ens32 ipv4.addresses "10.10.12.192/24 10.10.12.254" 

[root@rhce7 ~]# nmcli con mod ens32 +ipv4.dns 192.0.2.1  #關鍵符號"+"

[root@rhce7 ~]# nmcli con add con-name eth1 type ethernet ifname eth1
Connection 'eth1' (085c71ca-aac2-4851-a8a5-8e4f239e5e65) successfully added.
[root@rhce7 ~]# nmcli con add con-name eth2 type ethernet ifname eth2 ip4 192.168.56.120/24 gw4 192.168.56.254 ipv4.method manual
Connection 'eth2' (96238a53-4ffd-4358-aa73-15e7b7ae81c5) successfully added.

[root@rhce7 ~]# nmcli con del eth2

[root@rhce7 ~]# ip add show
1: lo:  mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth1:  mtu 1500 qdisc mq state UNKNOWN qlen 1000
    link/ether 00:50:56:a0:72:9a brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.190/24 brd 10.10.12.255 scope global eth1
    inet6 fe80::250:56ff:fea0:729a/64 scope link 
       valid_lft forever preferred_lft forever
3: eth2:  mtu 1500 qdisc mq state UNKNOWN qlen 1000
    link/ether 00:50:56:a0:51:2c brd ff:ff:ff:ff:ff:ff
    inet6 fe80::250:56ff:fea0:512c/64 scope link 
       valid_lft forever preferred_lft forever
[root@rhce7 ~]# ip addr show eth2
3: eth2:  mtu 1500 qdisc mq state UNKNOWN qlen 1000
    link/ether 00:50:56:a0:51:2c brd ff:ff:ff:ff:ff:ff
    inet6 fe80::250:56ff:fea0:512c/64 scope link 
       valid_lft forever preferred_lft forever