[j-nsp] punting base address packets to RE

[Saku Ytti]

On (2015-08-25 08:46 -0400), Frank Sweetser wrote:

Hey,

> 
> If I recall correctly, the base address of a subnet was originally used as
> an alternative broadcast address by some ancient equipment.  While it's not
> a behavior I'd expect to see actively used in modern equipment, seeing it
> handled as a special case as a receiver doesn't surprise me.
> 
> Based on this, it looks like it's handled as a directed broadcast:
> 
> https://www.juniper.net/techpubs/en_US/junose10.3/information-products/topic-collections/swconfig-ip-ipv6/id-25742.html

OP said they were punted, not forwarded to LAN. If they behaved by default as
if 'directed-broadcast' is enabled, it would be rather serious amplification
problem.

Directed-broadcast toggle permits the behaviour of flooding WAN arriving
packet as L2 bcast to LAN.
Typical use case is sending WOL packets over routed internet to LAN.

-- 
  ++ytti