Convert mac address to Cisco format (xxxx.xxxx.xxxx) and back (xx:xx:xx:xx:xx:xx)

convert-mac

#!/bin/bash

mac="$@"
if [[ ${mac} == ??:??:??:??:??:?? ]]; then
	sed 's/\://;s/\:/./;s/\://;s/\:/./;s/\://' <<< ${mac}
elif [[ ${mac} == ????.????.???? ]]; then
	sed 's/\.//g;s/\(..\)/\1:/g;s/:$//' <<< ${mac}
else
	echo 'That does not appear to be a mac address, try harder'
	exit 1
fi

nice