NAT v6->v4 and v4->v6 (was Re: WG Action: Conclusion of IP Version 6 )
nanog at 85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org
Sun Sep 30 01:34:33 UTC 2007
On Sun, 30 Sep 2007 10:54:34 +0930
Mark Smith <nanog at 85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org> wrote:
> On Sat, 29 Sep 2007 14:45:23 -1000
> Randy Bush <randy at psg.com> wrote:
> > > MPLS as well as the IETF softwires techniques (the MPLS model without
> > > using MPLS i.e. tunnel from ingress to egress via automated setup
> > > tunnels - gre, l2tp, or native IPv4 or IPv6) can or will shortly be
> > > able to be used to tunnel IPv6 over IPv4 or vice versa. softwires in
> > > effect treats the non-native core infrastructure as an NBMA layer 2.
> > >
> > > The advantage of these techniques verses dual stack is that they push
> > > the complexity of dual stack to the network ingress and egress
> > > devices.
> > >
> > > Dual stack isn't all that complicated, however when you think about
> > > running two forwarded protocols, two routing protocols or an
> > > integrated one supporting two forwarded protocols, having two
> > > forwarding topologies that may not match in the case of dual routing
> > > protocols, and having two sets of troubleshooing methods and tools, I
> > > think the simplicity of having a single core network forwarding
> > > protocol and tunnelling everyting else over it becomes really
> > > attractive.
> > huh? and your tunnels do not have *worse* congruency problems than dual
> > stack? gimme a break.
> I do not understand what you mean.
> The tunnelled traffic takes the same ingress-to-egress path through the
> core that it would if the core natively supported the tunnelled payload
> This is the basic BGP/MPLS model, using IPv4, IPv6, GRE or L2TP as the
> encapsulation, instead of MPLS.
It's also the RFC1772 BGP encapsulation model (section "A.2.3
Encapsulation"), with the difference being the end-node traffic
sources and sinks are the ingress and egress peers, rather than
an AS worth of them. The model isn't very new at all.
> "Sheep are slow and tasty, and therefore must remain constantly
> - Bruce Schneier, "Beyond Fear"
"Sheep are slow and tasty, and therefore must remain constantly
- Bruce Schneier, "Beyond Fear"
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