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Re: subnet prefix length > 64 breaks IPv6?
From: Glen Kent <glen.kent () gmail com>
Date: Sat, 24 Dec 2011 20:18:40 +0530


SLAAC only works with /64 - yes - but only if it runs on Ethernet-like
Interface ID's of 64bit length (RFC2464).

Ok, the last 64 bits of the 128 bit address identifies an Interface ID
which is uniquely derived from the 48bit MAC address (which exists
only in ethernet).

SLAAC could work ok with /65 on non-Ethernet media, like a
point-to-point link whose Interface ID's length be negotiated during the
setup phase.

If we can do this for a p2p link, then why cant the same be done for
an ethernet link?

Glen


Other non-64 Interface IDs could be constructed for 802.15.4 links, for
example a 16bit MAC address could be converted into a 32bit Interface
ID.  SLAAC would thus use a /96 prefix in the RA and a 32bit IID.

IP-over-USB misses an Interface ID altogether, so one is free to define
its length.

Alex


Regards, K.





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