3 Jan 2008 10:17
Re: IPv6 broadband provisioning
On Wed, 2 Jan 2008 19:51:58 +0100 (CET) Mikael Abrahamsson <swmike@...> wrote: > On Thu, 3 Jan 2008, Mark Smith wrote: > > > It's also common for CPE to run a caching DNS servers and NTP > > peers these days, which the downstream devices can use, so they'd break > > too. > > No, the CPE would use a loopback address for sourcing packets destined to > the outside (or it's LAN adress). > > > I understand the motive for the suggestion, however I don't really see > > how it couldn't be more trouble than it's worth. A ULA prefix on that > > upstream link would address some of the issues, but not all of them. > > I think to provide global Internet access you really need to ensure a > > fully globally addressed path to and from the Internet. > > So you think that "ip unnumbered loopback0" in IPv4 is really weird to > have on WAN interface? It's basically the same thing. > Hmm, I've been influenced by my environment. My environment is a Ethernet / DSL environment. I've been imagining deploying IPv6 in the N:1 model that's been mentioned earlier, so all CPE WAN interfaces within e.g. an exchange, are all sitting as nodes on the same /64. The N:1 model is attractive of course because at a minimum it avoids all the (pseudo in the case of ethernet) point to(Continue reading)
The concept still applies for N:1. The (pseudo) links in a N:1
environment are still there, with link-local addresses. The RG still
uses a loopback (or LAN) global scope address for global scope traffic.
There are some gotchas with DAD in a split-horizon environment like this
though...
David Miles can explain more around this - he's been looking at it in
detail.
aj.
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