[146950] in North American Network Operators' Group
Re: IPv6 prefixes longer then /64: are they possible in DOCSIS
daemon@ATHENA.MIT.EDU (Dmitry Cherkasov)
Tue Nov 29 06:48:15 2011
In-Reply-To: <3729C1E0-D8AF-479F-A50B-18EFE4407543@delong.com>
Date: Tue, 29 Nov 2011 13:46:39 +0200
From: Dmitry Cherkasov <doctorchd@gmail.com>
To: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
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@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 =C2=A0SLAAC is not u=
sed
>> 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
>
