v6 & DSL / Cable modems [was: Private use of non-RFC1918 IP space (IPv6-MW)]

Mark Andrews Mark_Andrews at isc.org
Thu Feb 5 01:40:25 UTC 2009

In message <498A40C1.8060702 at internode.com.au>, Matthew Moyle-Croft writes:
> Anthony Roberts wrote:
> >
> >
> > I don't think there's any need for the ISP's routers to advertise all the
> > prefixes they delegate. They'll advertise the /48 or whatever it is, and
> > then delegate chunks out of that.
> >   
> My apologies for not being clear:
> As I posted just before in reply to MarkA - I'm hoping that for the 
> MAJORITY of customers that I can use PD and dynamic /64s (or whatever) 
> local to a BRAS. 
> My FEAR is that people ("customers") are going to start assuming that v6 
> means their own static allocation (quite a number are assuming this).   
> This means that I have a problem with routing table size etc if I have 
> to implement that.
> I'm still not convinced though that, given DHCPv6 is going to be a 
> reality for DNS assignment etc, that stateless autoconfig is needed and 
> thus /64 doesn't have to be the smallest we assign.

	All IPv6 address assignments are leases.  Whether you get
	the address from a RIR, LIR or ISP.  The lease may not be
	renewed when it next falls due.  You may get assigned a
	different set of addresses at that point.  You should plan

	The only difference is the mechanisms used to assign the
	leases and the probability that you may have to renumber
	when the lease falls due.

Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: Mark_Andrews at isc.org

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