Refactor the common ARP structure fields between arp sending functions into the BASE_ARPMSG() macro to make it more obvious what is shared.
Refactor the common ARP structure fields between arp sending functions
into the BASE_ARPMSG() macro to make it more obvious what is shared.

Resequence the gateway arp address print and the arp state change to
AS_DEFENSE so that the debug prints are less confusing.  No other change.

niklata/ndhc