K 10
svn:author
V 6
sbruno
K 8
svn:date
V 27
2014-10-29T22:17:45.941898Z
K 7
svn:log
V 333
MFC r272720, 273061, 273062, 273063, 273064

Implement PLPMTUD blackhole detection (RFC 4821), inspired by code
from xnu sources.  If we encounter a network where ICMP is blocked
the Needs Frag indicator may not propagate back to us.  Attempt to
downshift the mss once to a preconfigured value.

Note, this is turned off by default.

END