Display network interfaces:

ip a
nmcli device status

Configure network interfaces:

ip 
nmcli

Test network connectivity:

ping

Display network connections:

netstat

Show IP addresses:

ip addr show

Show active connections:

nmcli connection show --active

Configure static IP:

nmcli
ip

Configure DHCP: nmcli, ifconfig, ip

Synchronize time with NTP: ntpdate, ntpd