Nmcli command learning (must, CentOS 8 defaults nmcli)

nmcli command

Refer to this: https://mp.weixin.qq.com/s/y64vMJqfbtDGXcTDz6R-mQ


< font color = Red > nmcli can be automatically completed, or is it relatively easy </font >

Just click nmcli to display all network card information:

[root@linux1 ~]# nmcli 
ens33: connected to ens33
        "Intel 82545EM"
        ethernet (e1000), 00:0C:29:D3:DD:51, hw, mtu 1500
        ip4 default
        inet4 192.168.38.123/24
        route4 192.168.38.0/24
        route4 0.0.0.0/0
        route4 172.18.0.0/16
        inet6 fe80::20c:29ff:fed3:dd51/64
        route6 ff00::/8
        route6 fe80::/64

ens37: connected to Wired connection 1
        "Intel 82545EM"
        ethernet (e1000), 00:0C:29:D3:DD:5B, hw, mtu 1500
        inet4 192.168.38.142/24
        route4 0.0.0.0/0
        route4 192.168.38.0/24
        inet6 fe80::a439:f7bd:b0c0:84be/64
        route6 fe80::/64
        route6 ff00::/8

nmcli level 1 option

[root@linux1 ~]# nmcli 
agent       device      help        networking  
connection  general     monitor     radio

View all network interface information

[root@linux1 ~]# nmcli connection show
NAME                UUID                                  TYPE      DEVICE 
ens33               c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
Wired connection 1  97f5b522-19ca-3a36-9ee2-7ad076028521  ethernet  ens37 

View the specified interface information

[root@linux1 ~]# nmcli connection show ens33
connection.id:                          ens33
connection.uuid:                        c96bc909-188e-ec64-3a96-6a90982b08ad
connection.stable-id:                   --
connection.type:                        802-3-ethernet
connection.interface-name:              ens33
connection.autoconnect:                 yes
connection.autoconnect-priority:        0
[root@linux1 ~]# nmcli device show ens33
GENERAL.DEVICE:                         ens33
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         00:0C:29:D3:DD:51
GENERAL.MTU:                            1500
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     ens33

Display all active links

[root@linux1 ~]# nmcli connection show --active 
NAME                UUID                                  TYPE      DEVICE 
ens33               c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
Wired connection 1  97f5b522-19ca-3a36-9ee2-7ad076028521  ethernet  ens37  

Delete a network card connection

[root@linux1 ~]# nmcli connection show 
NAME                UUID                                  TYPE      DEVICE 
ens33               c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
Wired connection 1  97f5b522-19ca-3a36-9ee2-7ad076028521  ethernet  ens37  
#delete
[root@linux1 ~]# nmcli connection delete Wired\ connection\ 1 
Connection 'Wired connection 1' (97f5b522-19ca-3a36-9ee2-7ad076028521) successfully deleted.
#See
[root@linux1 ~]# nmcli connection show 
NAME   UUID                                  TYPE      DEVICE 
ens33  c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33 

Manually assign an IP to ens37, which is permanent and generates configuration files

# View Network Card Name
[root@linux1 ~]# ip addr show ens37
4: ens37: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:d3:dd:5b brd ff:ff:ff:ff:ff:ff
#Start acting
# Network card type is ethernet ifname, network interface name ens37,ip, gateway, BOOTPROTO is automatic
[root@linux1 ~]# nmcli connection add type ethernet ifname ens37 ipv4.addresses 192.168.38.
142/24 ipv4.gateway 192.168.38.2 ipv4.method manual 
Connection 'ethernet-ens37' (5397a06b-81d2-47ce-a06f-0c76af02c5b4) successfully added.
[root@linux1 ~]# nmcli connection show
NAME            UUID                                  TYPE      DEVICE 
ens33           c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
ethernet-ens37  5397a06b-81d2-47ce-a06f-0c76af02c5b4  ethernet  ens37 
# View the generated configuration file
[root@linux1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-ethernet-ens37

Modify IP or some network parameters

#The original appearance
[root@linux1 ~]# nmcli connection show 
NAME            UUID                                  TYPE      DEVICE 
ens33           c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
ethernet-ens37  5397a06b-81d2-47ce-a06f-0c76af02c5b4  ethernet  ens37
#Modified appearance
[root@linux1 ~]# nmcli connection modify ethernet-ens37 con-name ens37
[root@linux1 ~]# nmcli connection show 
NAME   UUID                                  TYPE      DEVICE 
ens33  c96bc909-188e-ec64-3a96-6a90982b08ad  ethernet  ens33  
ens37  5397a06b-81d2-47ce-a06f-0c76af02c5b4  ethernet  ens37
#Add DNS
[root@linux1 ~]# nmcli connection modify ens37 +ipv4.dns 123.123.123.123

Increase IP, Delete IP

[root@linux1 ~]# nmcli connection modify ens37 +ipv4.addresses 192.168.38.161/24
[root@linux1 ~]# nmcli connection modify ens37 -ipv4.addresses 192.168.38.161/24

Restart network

[root@linux1 ~]# nmcli connection reload 
[root@linux1 ~]# systemctl restart network

Tags: Linux network DNS

Posted on Sun, 06 Oct 2019 17:38:33 -0700 by 0riole