[ipv6-wg] dynamic or static IPv6 prefixes to residential customers

Yes, that's the RFC4192 method, which we have used for an enterprise (partial) renumber.

I think Ivan's question is more about the CPE behaviour if there's a no-flag-day renumbering event?  If the renumbering is planned, it ought to be possible to introduce the new prefix, turn down the preferred timer on the old one, run with both for a while, then remove the old prefix.  If there's something the implementation or standards stopping that,what is it, and how do we fix it?

I think something similar is supported in IOS if you use 6to4 and your CPE's IPv4 address changes - maybe Eric can comment on that. Not that I'd suggest using 6to4 any more ;)

Tim

On 27 Jul 2011, at 16:07, Eric Vyncke (evyncke) wrote:

> Ivan
> 
> My understanding is that while a previous prefix cannot be removed by setting the lifetime to 0 (for the reason you cited) it can be deprecated instantly by setting the preferred timer to 0. Which has the same net effect of using the new prefix.
> 
> -éric
> 
>> -----Original Message-----
>> From: ipv6-wg-admin at ripe.net [mailto:ipv6-wg-admin at ripe.net] On Behalf Of
>> Ivan Pepelnjak
>> Sent: mercredi 27 juillet 2011 10:26
>> To: 'Tim Chown'
>> Cc: ipv6-wg at ripe.net
>> Subject: RE: [ipv6-wg] dynamic or static IPv6 prefixes to residential
>> customers
>> 
>> There's a minimum timeout of 2 hours hard-coded in the SLAAC RFC to prevent
>> DoS attacks. Some details here:
>> 
>> http://blog.ioshints.info/2010/12/small-site-multihoming-in-ipv6-mission.html
>> 
>> Then there's the failure to detect PPPoE session loss:
>> 
>> http://blog.ioshints.info/2010/10/dhcpv6-over-pppoe-total-disaster.html
>> 
>> Last but definitely not least, CPEs tend to copy lease time from DHCPv6 PD to
>> SLAAC prefix validity time (and I found no way to change that behavior in
>> Cisco IOS), so you either overload your DHCPv6 server by using short leases
>> or risk having delegated prefixes that will stay in the customer's CPEs for a
>> long time.
>> 
>> Ivan
>> 
>>> -----Original Message-----
>>> From: ipv6-wg-admin at ripe.net [mailto:ipv6-wg-admin at ripe.net] On Behalf Of
>>> Tim Chown
>>> Sent: Wednesday, July 27, 2011 4:08 PM
>>> To: ipv6-wg
>>> Subject: Re: [ipv6-wg] dynamic or static IPv6 prefixes to residential
>>> customers
>>> 
>>> 
>>> On 27 Jul 2011, at 14:45, Ivan Pepelnjak wrote:
>>> 
>>>> Unfortunately you have to do static prefix delegation because it's
>>> impossible to renumber the customer's inside LAN within a reasonable time
>>> interval with today's state of IPv6 SLAAC.
>>> 
>>> Why impossible?
>>> 
>>> Tim
>