[PATCH v2] Send an initial ARP request to resolve the guest IP address

Dear David, Thanks a lot for your timely review. I applied all of your suggested improvements, and moreover introduced MAC_BROADCAST, analogous to the already existing MAC_ZERO, to improve readability. Regarding the maximum of 80 columns per line, I did fix it at the one place you asked for, but noticed that there are two other places where my patch hits that limit. However, I'm not sure about the expected code formatting when breaking those lines. So if those need to be broken as well, I'd be grateful for coding style suggestions. Best regards, Volker