Document the fact that blackhole routes normally need to be bound to lo(4) interfaces to have an effect, and that this is not needed when using IP fast forwarding.
Document the fact that blackhole routes normally need to be bound
to lo(4) interfaces to have an effect, and that this is not needed
when using IP fast forwarding.

Sponsored by:	eXtensible Open Router Project <URL:http://www.xorp.org/>
MFC after:	3 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase