Lookup in the ATU can be performed starting from a given MAC
address. This is faster than starting with the first possible MAC
address and iterating all entries.
Entries are returned in numeric order. So if the MAC address returned
is bigger than what we are searching for, we know it is not in the
ATU.
Using the benchmark provided by Volodymyr Bendiuga
<volodymyr.bendiuga@gmail.com>,