ip command nuggets

View IP address related information (all interfaces):

ip address

or

ip a

View the ARP table

ip neighbors

Cross-reference the IP addresses in the ARP cache with their local hostnames (if known). Replace “@localhost” with the hostname/IP address of the DNS server you want to query, or remove it altogether to use the system’s default DNS server:

for ip in $(ip nei | awk '{print $1}'); do dig -x $ip @localhost | grep "in-addr.arpa"; done

Or, wrapped in a shell function:

arp () {
  for ip in $(ip nei | cut -d' ' -f1); do 
    dig -x $ip @localhost | grep "in-addr.arpa"; 
  done
}

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