Display all network interfaces and IP address
ip a
Display eth0 address and details
ip addr show dev eth0
Query or control network driver and hardware settings
ethtool eth0
Send ICMP echo request to host
ping host
Display whois information for domain
whois domain
Display DNS information for domain
dig domain
Reverse lookup of IP_ADDRESS
dig -x IP_ADDRESS
Display DNS IP address for domain
host domain
Display the network address of the host name.
hostname -i
Display all local IP addresses of the host.
hostname -I
wget http://domain.com/file
Display listening tcp and udp ports and corresponding programs
netstat -nutlp