Evil Bit and Spread Spectrum IP Addressing - NANOG Source Address Shaping
nanog.guru at gmail.com
Sun Mar 4 10:22:15 CST 2012
Common Misconception: One additional bit of IPv4 Addressing will solve
The Evil Bit (or spare unused bit) can be used to store (restore) one bit
The Left-Most bit of the 32-bit Source Address Field can be SET to
Zero no matter what the original value. The Evil bit can be set IFF
the Left-Most bit is **changed**.
Setting the Left-Most bit to zero **folds** this table in half.
Setting the Left-Most bit to ONE would move return traffic to the
upper half of the Spectrum which has vast quantities of unused /8s
Wide-spread consensus shows that TWO bits can work. Three bits folds
the table to 1/8th.
Governments want a 4-bit Return Prefix to their Super-Hubs for
The U.S.FCC is expected to issue the regulations on how Spread
Spectrum Source Address Shaping will work in their licensed CPE
wireless devices. There are 160-bits
in the deprecated header so there are many ways to go.
One-Way Broadcast IP Addressing is now available. The Source Address
Field is used
for the second half of the 64-bit Destination Address. The DF (Did
Flip) bit near the Evil
Bit is used to note the two halves of the Destination Address have
NANOGers simply route 32 and then 32 after the flip based only on the
There is no Source Address, only a channel (port).
Keywords: WRT DNSMASQ Tomato WIFI Linux CPE
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