1. List interfaces:

# sudo nmcli device status

Example output:
DEVICE  TYPE      STATE                   CONNECTION         
ens18   ethernet  connected               Wired connection 1 
lo      loopback  connected (externally)  lo                 

2. List current connections:

# sudo nmcli connection show

NAME                UUID                                  TYPE      DEVICE 
Wired connection 1  be3443b1-e1a3-491b-9eb9-3e8bdb1df0c8  ethernet  ens18  
lo                  2896417b-a577-418d-a45f-3c19b2a33f1e  loopback  lo     

3. Check if connection is using DHCP (auto) or not:

# sudo nmcli connection show "<CONNECTION_STRING_NAME>" | grep ipv4.method

For example, if connection name is "Wired connection 1" (use either 'nmcli device status' or 'nmcli connection show' to get actual name):

# sudo nmcli connection show "Wired connection 1" | grep ipv4.method

Output if using static IP:

ipv4.method:                            manual

Output if using DHCP autoconfig:

ipv4.method:                            auto

WARNING: Not recommended to do this over a remote session. You'll get disconnected.

You can use this to setup static IP from DHCP or change static IP.

Before you begin, you need to have these information ready:

1. Valid Connection Name = <CONNECTION_STRING_NAME> (from nmcli)
2. Valid IP Address. (0.0.0.0 - 255.255.255.255) = <IP_Address>
   
3. Valid IP Netmask in bits. (0 - 32) <NetMask>
   
4. Gateway IP Address = <GW_IP>
   
5. DNS Server IP 1 = <DNS_1> (required)
6. DNS Server IP 2 = <DNS_2> (optional - you do not need to specify second DNS server)

1. Command syntax:

# sudo nmcli connection modify "<CONNECTION_STRING_NAME>" ipv4.addresses <IP_Address>/<NetMask> ipv4.gateway <GW_IP> ipv4.dns "<DNS_1> <DNS_2>" ipv4.method manual

Example:

# sudo nmcli connection modify "Wired connection 1" ipv4.addresses 192.168.100.1/24 ipv4.gateway 192.168.100.254 ipv4.dns "8.8.8.8" ipv4.method manual

2. Stop the interface.

WARNING: Not recommended to do this over a remote session. You'll get disconnected.

# sudo nmcli connection down "<CONNECTION_STRING_NAME>"

NOTE: This command will bring down the interface and disconnect any remote sessions!

Example:

# sudo nmcli connection down "Wired connection 1"

# sudo nmcli connection up "<CONNECTION_STRING_NAME>"

Example:

# sudo nmcli connection up "Wired connection 1"