Spread Spectrum IP Addressing - SOURCE Address Field ROTATED|shifted? Left 2 Bits

Guru NANOG nanog.guru at gmail.com
Sat Mar 3 19:34:20 UTC 2012


Common Misconception

With Spread Spectrum IP Addressing the 32-bit Source Address Field is
Shifted LEFT 2-bits by the originator of the packet.

That Folds the IPv4 Legacy Address Space into 1/4th tsize table

The lost 2-bits are stored in the Right-Most 2 bits of the 32-bit
field and in other places in the IPv4 Header

The Destination can easily recover the Source Address - if the proper
algorithms are in use

Responses blindly sent back to the shifted Source Address may fall
into agile hands or not

With the advanced Spread-Spectrum techniques, additional addressing
bits are created from the noise intentionally stored in the Right-Most
2 bits

NANOG Operators buying /8s or /6s may want to look at the
Spread-Spectrum CODE in the Linux-based CPE Routers

The following table is deprecated and 1/4th the size:
http://www.iana.org/assignments/ipv4-address-space/ipv4-address-space.txt

With Spread-Spectrum collisions and mis-directions are OK and expected but other
techniques ensure the packets get to the right place.

http://NANOG.GURU




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