1 Problem Description

CentOS VMS cannot display local IP addresses, as shown in the following figure:

2 Tried methods

Change ONBOOT to YES as shown here:

However, the original nic configuration is also YES, so the modification method is useless. I tried to restart the NIC service:

systemctl restart network
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The IP still doesn’t work.

3 reasons

There are two common Linux network management services:

  • networkservice
  • NetworkManagerservice

NetworkManager is a basic service that is usually used on servers and also on the GUI. NetworkManager is usually installed on the GUI to facilitate IP configuration. Note that only one of the two services takes effect. In this case, there should be a conflict between the two, resulting in the normal display of local IP, can be used

systemctl status network
systemctl status NetworkManager
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Check the status of the two services. If the two services are not in conflict, it should be the cause of the configuration error.

4 Solutions

4.1 the use ofnetwork

Disable NetworkManager:

systemctl stop NetworkManager
systemctl status NetworkManager
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Restart network after disabling:

systemctl restart network
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This will show the local IP.

/etc/sysconfig/network-scripts /etc/sysconfig/network-scripts /etc/sysconfig/network-scripts/ifcfg-ens33

4.2 the use ofNetworkManager

To use NetworkManager, disable NetworkManager:

systemctl stop network
systemctl status network
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Start NetworkManager again:

systemctl start NetworkManager
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Next, use nmCLI.

4.2.1 Hosting status

First look at the managed status:

nmcli n
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If disabled is displayed:

Open:

nmcli n on
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4.2.2 equipment

View device:

nmcli d
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The author’s machine shows as follows:

Next, you can create a connection in two ways: dynamic/static IP:

Create a connection using a static IP address
nmcli c add typeEthernet con-name connect_name_1 ifname ens33 ipv4.addr 192.168.126.151/24 ipv4.gateway 192.168.126.1 ipv4.method manualCreate a connection using a dynamic IP address
nmcli c add type ethernet con-name connect_name_2 ifname ens33 ipv4.method auto
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Holdings of staticipway

nmcli c add typeEthernet con-name connect_name_1 ifname ens33 ipv4.addr 192.168.126.151/24 ipv4.gateway 192.168.126.1 ipv4.method manualCopy the code

Parameter Description:

  • nmcli c add: Create a connection
  • type: Connection type
  • con-name: Connection name
  • ifname: the network card name
  • ipv4.addr:ipv4staticipAnd here is the192.168.126.151.24Indicates the subnet mask
  • ipv4.gateway: gateway, put the lastipThe last place1All right, so here it is192.168.126.1
  • ipv4.method: The following parametersmanualStatic configurationip, it is important to note that this parameter is the defaultauto, that is, if this parameter is not specified, two will appearipOne static + one dynamic

After the connection is created, the IP should be displayed:

If the IP still cannot be displayed, you can manually connect to the device:

nmcli d connect ens33
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4.2.4 dynamicipway

nmcli c add type ethernet con-name connect_name_2 ifname ens33 ipv4.method auto
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The parameter is the same as the preceding parameter. The difference is auto, which indicates that the IP address is configured dynamically. In this way, the configuration is complete.

If there is still no IP, try manually connecting to the device:

nmcli d connect ens33 
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