Some useful network troubleshoot command in Linux
( 1 ) ifconfigThis is standard network interface show command in all Linux flavor. From this we can verify interface status, mode, MAC address, but this will show only physical interface details
( 2 ) ifconfig -a
This is work same as above ifconfig command but only difference is that it show all interface including logical
In some cases Ifconfig command not work then also we can troubleshoot network using below mention commands.
( 3 ) ip addr show
To view the details of the network interface card such as IP address, Link status, Mac address.
( 4 ) ip link
Used for port status to check it is UP or Down.

( 5 ) ip link -s link
To view network interface status as well as Upload and Download traffic on interface in Rx and Tx.