Method 1 – Using NetworkManager Service

Use the followings commands to start/stop network service on your CentOS/RHEL 8 Linux system.

sudo systemctl start NetworkManager.service
sudo systemctl stop NetworkManager.service

Use the followings commands to restart network service on your CentOS/RHEL 8 Linux system.

sudo systemctl restart NetworkManager.service

Method 2 – Using nmcli Tool

The nmcli is the command-line utility for the managing NetworkManager on CentOS/RHEL 8 Linux system. You can simply use this utility to stop/start network service on your CentOS 8 or RHEL 8 system.

sudo nmcli networking off
sudo nmcli networking on

The above command will disable/enable the network connections on CentOS 8 or RHEL 8 Linux system.