To retrieve essential network information, this is strictly layer 3 information, enter the following command:
:~$ ip address
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: wlp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
link/ether 6a:05:5c:78:92:8c brd ff:ff:ff:ff:ff:ff permaddr 14:ac:60:47:c0:19
inet 192.168.1.154/24 brd 192.168.1.255 scope global dynamic noprefixroute wlp2s0
valid_lft 13536sec preferred_lft 13536sec
inet6 fe80::cc98:92bc:fd5c:648c/64 scope link noprefixroute
valid_lft forever preferred_lft forever
There are many other commands that give you layer 3 information, like the routing:
glasco@klingon:~$ ip route
default via 192.168.1.1 dev wlp2s0 proto dhcp src 192.168.1.154 metric 600
192.168.1.0/24 dev wlp2s0 proto kernel scope link src 192.168.1.154 metric 600
glasco@klingon:~$