[TriLUG] raspberry pi easily find IP

[Michael Hrivnak]

This may be old news, but today I discovered an easy way to spot a
raspberry pi in a crowd, and perhaps it will be of use to others.

A coworker brought in a headless raspberry pi, connected it to the network,
and wasn't sure how to determine its IP address. The subnet is quite
crowded and active, so it wasn't convenient to consult a dhcp server or
scan with nmap. I thought perhaps we could find the MAC address printed on
the device and then use ARP. Alas, the address was nowhere to be found.

Thankfully, the Raspberry Pi Foundation has its own MAC address space.

http://hwaddress.com/mac/B827EB-000000.html

So it was easy to find the device and its IP address with arp-scan.
(addresses changed to protect the guilty)

$ sudo arp-scan --interface=em1 192.168.1.0/24| grep 'b8:27:eb'
192.168.1.169 b8:27:eb:88:01:ab (Unknown)

Michael