nanog mailing list archives

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


From: "Keith Medcalf" <kmedcalf () dessus com>
Date: Sat, 03 Mar 2012 14:13:33 -0700


Is it April already?  I though April Fools Day wasn't until next month.

I did, I did.  I did see a snake-oil salesman!


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-----Original Message-----
From: Guru NANOG [mailto:nanog.guru () gmail com]
Sent: Saturday, 03 March, 2012 12:34
To: nanog () nanog org
Subject: Spread Spectrum IP Addressing - SOURCE Address Field
ROTATED|shifted? Left 2 Bits

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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