Helper subroutines to support parts of the Netdisco application.
There are no default exports,
:all tag will export all subroutines.
Given a Device database object and a MAC address, perform various sanity checks which need to be done before writing an ARP/Neighbor entry to the database storage.
Returns false, and might log a debug level message, if the checks fail.
Returns a true value if these checks pass:
Optionally pass a cached set of Device port MAC addresses as the third argument,
check_mac will retrieve this for itself from the database.