Let me just preface this post by saying “This is not a persistent configuration. If you boot the system, these settings will be lost unless you save them via the /etc/sysconfig/network-scripts files or through NetworkManager.

Here is how you can manually configure the IP address and gateway in CentOS/RHEL7:

Configure the IP address and subnet mask:

# ip addr add aaa.bbb.ccc.ddd/ss dev interface

For example:

# ip addr add dev eno1

Likewise, to remove the IP address:

# ip addr del dev eno1

To configure the default gateway:

# ip route add default via ddd.ccc.bbb.aaa dev interface

For example:

# ip route add default via dev eno1

Same kind of thing to remove the currently configured gateway:

# ip route del default via dev eno1

Once you have the interface configure, bring it up:

# if link set eno1 up

And to take it down:

# if link set eno1 down