>From a requirements point of view I am not sure I would enforce these sort of restrictions.
John On 11/29/11 6:59 AM, "Dmitry Cherkasov" <doctor...@gmail.com> wrote: >John, > >I am determining technical requirements to IPv6 provisioning system >for DOCSIS networks and I am deciding if it is worth to restrict user >to use not less then /64 networks on cable interface. It is obvious >that no true economy of IP addresses can be achieved with increasing >prefix length above 64 bits. > >As for using EUI-64, unlike random or sequential generation it >provides predictable results that may be desired, e.g. for tracking >some device migration between different networks. > >Dmitry Cherkasov > > > >2011/11/29 Brzozowski, John <john_brzozow...@cable.comcast.com>: >> Dmitry, >> >> >> You could consider the use of prefixes longer than the /64 on CMTS >> interfaces, however, it is not clear to me why this would be done. >> Further, most DHCPv6 implementations do not require that the generated >> IPv6 address be eui-64 based. A randomized algorithm could also be >>used. >> Another consideration is what happens after IPv6 is used for addressing >> cable modems. What happens when you want to address CPE or CPE routers? >> You are right back to /64 or shorter depending on the type of device >>being >> provisioned. >> >> FWIW - we have found that there are distinct benefits to using IPv6 >>beyond >> the amount of addresses that are available. The use of /64 is tightly >> coupled with these benefits. >> >> Can you elaborate as to why one would want to or need to use prefixes >> longer than /64? >> >> John >> >> On 11/28/11 6:37 AM, "Dmitry Cherkasov" <doctor...@gmail.com> 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 >>> >> >