Spread Spectrum NANOG Operational Alert - Source Addresses with 240 to 255

Tue Mar 6 21:30:08 UTC 2012

Adding four more bits to the Left of the Source Address and setting
those bits to 1111 (0xF) can help to start the migration to "Regions"
and more IPv4 Addresses - Using and Re-Using legacy spectrum
<spectrumhttp://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.txt>.

The real Source Address is shifted 4 bits to the Right. The bits
shifted off are placed in the Deprecated TOS field in the DDDD bits.
The new TOS field has the SSSS.DDDD for the CPE.

If a router attempts to reply or return to the Source Address it will
hit one of the Regional Hubs. There are 16 of those.
Agile CPE can reply in other ways to the Agile CPE that sent the
Source Address with the 1111 bits.

NANOG operators may want to study the evolution of 6to4 (2002:IPv4:0000) to
6RD (IPv4:IPv4) which tunnels using Re-Used legacy 32-bit addresses.

The Legacy 32-bit Address Space will likely be around a long long time
and be reused in many ways.
That may increase the market value of /8s. Brokers are now selling /8s
on the open market.

http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.txt
<spectrumhttp://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.txt>

16 /8s for "Future use" - it looks like the "Future" has arrived

240/8  Future use                                     1981-09
          RESERVED    [15]
                                   ...
   255/8  Future use                                     1981-09
             RESERVED  [15]
http://tools.ietf.org/html/draft-gundavelli-v6ops-community-wifi-svcs
<http://tools.ietf.org/html/draft-gundavelli-v6ops-community-wifi-svcs-014.13.>

014.13. <http://tools.ietf.org/html/draft-gundavelli-v6ops-community-wifi-svcs-014.13.>
Overlapping IPv4 Address Support Wi-Fi Service Provider may segment the
network into regions. Two regions may use overlap IPv4 address space. This
is particularly important when the Internet is transitioning to IPv6. The
Wi-Fi SP may not have enough unique public IPv4 addresses to globally
address large number of Wi-Fi device.