[147892] in North American Network Operators' Group
Re: subnet prefix length > 64 breaks IPv6?
daemon@ATHENA.MIT.EDU (Glen Kent)
Sun Dec 25 05:19:02 2011
In-Reply-To: <CALFTrnPa73oPkUuyoWW9GVQNcn9WpE6Y8PvDutawWJKaNS2iQQ@mail.gmail.com>
Date: Sun, 25 Dec 2011 15:48:00 +0530
From: Glen Kent <glen.kent@gmail.com>
To: Ray Soucy <rps@maine.edu>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Hi Ray,
> prefixes on the same link. =A0Choosing 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:
Registry:
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]
Glen
