Recently I wrote a python script for converting mac addresses (which you can download from github) and the reason I wrote it is because I receive emails like this...

The background is, I'm working on an 802.1x project, I need to find the printer, the quickest solution in this case is to look in the ARP cache of the router/switch on site.

The irritant is that in the email the MAC is in EUI format, but routers/switches are in Cisco's. To Further irritate, Cisco ISE and ACS use EUI format so if someone sends you a MAC address from a switch or their windows machine then you need to convert it, I've spent a lot of time replacing dots and dashes :D

Today, I realised that I could use Apple's Automator to grab text from somewhere... I could then parse it through my python scripts and have the results in my clip board... ready for pasting!

Below is my automator workflow

In the python field you can't see the full text... paste in this...

#!/usr/bin/env python
import sys

addr=str(sys.argv[1])

if "." in addr:
    delimiter = "."
elif ":" in addr:
    delimiter = ":"
elif "-" in addr:
    delimiter = "-"

# Eliminate the delimiter
m = addr.replace(delimiter, "")

# Normalise Case
m = m.lower()
u = m.upper()

eui= ":".join(["%s%s" % (m[i], m[i+1]) for i in range(0,12,2)])

print eui

If you've having issues creating a new automator service from the screenshot I have uploaded my Convert to EUI MAC.workflow save it to ~/Library/Services

Once you're all setup, you'll be able to right click any mac address and convert it. I've also created a Convert to Cisco MAC.workflow if you need it in router/switch format.