unknown-dhcp.sh

#!/bin/bash
# Filter unknown Mac-Adresses from daemon.log and display Manufacturer
# works with UNIVENTION 4
# depends on: oui.txt from https://linuxnet.ca/ieee/oui/
# (c) 2019 by Klaus Kappel
# Use under GPL3

txt=/var/www/unknown.txt
tmp=$(mktemp)

function vendor {
    vm=$(echo $1 | cut -c1-8)
    trans=$(echo "$vm" | tr ':' '-')
    upper=$(echo "$trans" | tr '[a-z]' '[A-Z]')
    vendor=$(cat /usr/local/src/mac/oui.txt | grep $upper | cut -f3)
    echo $1 $vendor
}


grep "unknown client" /var/log/daemon.log | cut -c49-66 | sort -u > $tmp

echo "Unbekannte MacAdressen im LAN" > $txt
echo "=============================" >> $txt
for m in $(cat $tmp); do
  vendor $m >> $txt
done

date "+%d.%m.%Y %H:%M" >> $txt

rm $tmp