Random Unix Gems

GetMAC()
{
  if [ -n "$1" ]; then
    OID="00:16:3e"
    RAND=$(echo $1 | md5sum | sed 's/\(..\)\(..\)\(..\).*/\1:\2:\3/')
    echo "$OID:$RAND"
  else
    echo "ERROR: please supply hostname to create MAC address from, e.g.:"
    echo "       $FUNCNAME myhost"
  fi
}

echo 00:16:3e$(gethostip 10.1.2.11 | awk '{ print tolower(substr($3,3)) }' |sed 's/.\{2\}/:&/g' )

 while read ip; do dig +noall +answer -x $ip; done < ip-list.txt

ss -aunp  (udp with process and all info)

ss -ltpn (tcp listeners with processes) 

ss -ltpan (tcp with all and processe info )