Good evening everyone,
I am trying to retrieve in a text file the MAC address of the pc that I want to wake up with a wake On Lan.
when i am on my server and i run the following command
root@localhost# tcpdump -UlnXi eth0 proto 0x0842 or udp port 9 2>/dev/null | sed -nE 's/^.*20: (ffff|.... ....) (..)(..) (..)(..) (..)(..).*$/\2:\3:\4:\5:\6:\7/p'
xx:xx:xx:xx:xx:xx
i see on the screen the MAC address of the pc but now I want to put this MAC address in a file called mac.txt and I can’t do it
Thanks for your help
osiris69
Why don’t you simply redirect the output into a file?
tcpdump options | sed options > mac.txt
Why do you get the MAC from tcpdump?
- Don’t you have access to the physical device / know its MAC?
- Don’t you have IP address of the device? If you know the address, then
ping -c 1 $ADDR
ip neigh | grep $ADDR
ip neigh | grep $ADDR | cut -d' ' -f 5 > mac.txt
thank you jlehtone for answering me,
in fact I send with a web application a wake on lan to a pc and that’s where I want to recover the destination of MAC address.
when i do the command
tcpdump options | sed options > mac.txt
i get an empty mac.txt file, that’s exactly my problem
Thank you
Osiris69