This can be easily done by adding an "ip" command to system startup with RHEL8 "systemctl".
1. Create a run script for ip to setup a loopback device on 192.168.10.1:
echo 'ip addr add 192.168.10.1/24 dev lo' >/usr/local/sbin/loopback2.sh
chmod 700 /usr/local/sbin/loopback2.sh
2. Create the service file:
vi /lib/systemd/system/loopback2.service
or
systemctl edit loopback2
2. Have it start as service with systemctl:
[Unit]
after=network
[Service]
ExecStart=/usr/local/sbin/loopback2.sh
[Install]
WantedBy=default.target
3. Enable and auto start:
systemctl enable loopback2.service
systemctl start loopback2.service
4. Confirm the setup:
ip addr
systemctl status loopback2
