Essential Linux Networking Commands

tcpdump#

Check for packets flowing out from an interface for a specific CIDR#

sudo tcpdump -v -i wlo1 dst net 192.168.0.0/16

Explanation:

• -i is for interface. wlo1 is the interface name.
• dst specifies destination IP
• net specifies it’s a CIDR range.

ip#

List routing table#

ip route

Find which interface and route a particular IP is taking#

ip route get 192.168.1.1

ifconfig#

Find the primary IP of local machine#

Get the IP of all interfaces:#

ifconfig | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*' | grep -v '127.0.0.1'

Get the IP of a specific interface:#

For eg (wlo1):

ifconfig wlo1 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*' | grep -v '127.0.0.1'

Source