which means "always stay in the standard mode of PPPoE operation
regardless of any junk floating around."
As the referenced PR stated clearly, the old default setting of 0
was extremely dangerous because it opened a possibility for a
spurious frame not only to put down a single PPPoE node running
FreeBSD, but to plague *every* FreeBSD node in a PPPoE network in
such a way that those nodes would keep poisoning each other until
rebooted simultaneously.
PR: kern/47920
Reviewed by: Gleb Smirnoff <glebius <at> cell.sick.ru>
MFC after: 1 week