This scalar globally enables/disables discarding of the IP
well-known addresses described below:
-------------------------------------------------------------------------------
| Address block | Present use
|-------------------------------------------------------------------------------
|0.0.0.0/8 | Addresses in this block refer to source hosts
|(except 0.0.0.0/32 | on 'this' network.
| as source address) |
|------------------------------------------------------------------------------
|127.0.0.0/8 | This block is assigned for use as the Internet host loop-back address.
|-----------------------------------------------------------------------------------------------------
|192.0.2.0/24 | This block is assigned as 'TEST-NET'
| | for use in documentation and example code.
|---------------------------------------------------------------------------
|224.0.0.0/4 as source. | This block, formerly known as the Class D address space,
| | is allocated for use in IPv4 multicast address assignments.
|-------------------------------------------------------------------------------------------
|240.0.0.0/4 |
|(except 255.255.255.255/32 | This block, formerly known as the Class E address space, is reserved.
| as destination address) |
|-------------------------------------------------------------------------------------------------------