IPv6 prefixes longer then /64: are they possible in DOCSIS networks?

Tue Nov 29 11:46:39 UTC 2011

Owen,

Currently I research on IPv6 provisioning systems and I need to decide
whether the ability to use longer then /64 prefixes should be
supported in them or not. If we restrict user to using /64 per network
we need to have convincing reasons for this. Best practice and common
sense stand for using /64 but this may be not sufficient for some
people.

Dmitry Cherkasov

2011/11/28 Owen DeLong <owen at delong.com>:
> You can probably do it, but, what do you gain by doing so?
>
> Owen
>
> On Nov 28, 2011, at 3:37 AM, Dmitry Cherkasov wrote:
>
>> Hello everybody,
>>
>> It is commonly agreed that /64 is maximal length for LANs because if
>> we use longer prefix we introduce conflict with stateless address
>> autoconfiguration (SLAAC) based on EUI-64 spec. But  SLAAC is not used
>> in DOCSIS networks. So there seems to be no objections to use smaller
>> networks per cable interfaces of CMTS. I was not able to find any
>> recommendations anywhere including Cable Labs specs for using
>> prefixes not greater then /64 in DOCSIS networks. Some tech from ISP
>> assumed that DHCPv6 server may generate interface ID part of IPv6
>> address similarly to EUI-64 so MAC address of the device can easily be
>> obtained from its IPv6 address, but this does not seem like convincing
>> argument. What do you think?
>>
>>
>> Dmitry Cherkasov
>