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Re: subnet prefix length > 64 breaks IPv6?
From: Glen Kent <glen.kent () gmail com>
Date: Sun, 25 Dec 2011 15:48:00 +0530

Hi Ray,

prefixes on the same link.  Choosing to make use of a 120-bit prefix
(for example) will do nothing to protect against a rogue RA announcing
its own 64-bit prefix with the A flag set.

I could not find any "A flag" in the RA. Am i missing something?

From http://www.iana.org/assignments/icmpv6-parameters:

RA Option Bit  Description                              Reference
-------------  ---------------------------------------  ---------
0              M - Managed Address Configuration Flag   [RFC2461]
1              O - Other Configuration Flag             [RFC2461]
2              H - Mobile IPv6 Home Agent Flag          [RFC3775]
3              Prf - Router Selection Preferences       [RFC4191]
4              Prf - Router Selection Preferences       [RFC4191]
5              P - Neighbor Discovery Proxy Flag        [RFC4389]
6-53           R - Reserved; Available for assignment   [RFC5175]
54-55          Private Experimentation                  [RFC5175]


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