Subject: Re: [lisp] Flow label redux

From: [email-masked] (Noel Chiappa)
Date: Fri, 7 Aug 2009 23:13:30 -0400 (EDT)

> From: Christopher Morrow <[email-masked]>

    > While a non-lisp node receiving a LISP udp/0 packet dropping it seems
    > fine to me, a translator dropping a udp/0|null-sum packet instead of
    > translating it properly or telling the source-system: "oops, something
    > bad happened" is unacceptable (in my mind).

Ow; now you're making my head hurt.

I don't think LISP was ever intended to work in the circumstance where an
IPv[46] xTR was talking directly to an IPv[64] (i.e. the opposite of the
other one) xTR, via a IPv[4-6] translator box - just like we don't expect
IPv4 routers to talk to IPv6 routers through an IPv[4-6] translator box.

So I'm not sure we need to worry about that case either? Or do we need that
case to work? Are there really going to be operational cases _during the term
of the LISP experimental phase_ with IPv4-only xTRs needing to talk to
IPv6-only xTRs?

(That is of course separate from the case where a IPv6-only xTR wants to talk
to another IPv6-only xTR, and there is no direct v6-native path between them -
it was at that point that my head started to hurt....)

	Noel

---

From: Christopher Morrow <[email-masked]>
Date: Sat, 8 Aug 2009 01:12:24 -0400

On Fri, Aug 7, 2009 at 11:13 PM, Noel Chiappa<[email-masked]> wrote:
>    > From: Christopher Morrow <[email-masked]>
>
>    > While a non-lisp node receiving a LISP udp/0 packet dropping it seems
>    > fine to me, a translator dropping a udp/0|null-sum packet instead of
>    > translating it properly or telling the source-system: "oops, something
>    > bad happened" is unacceptable (in my mind).
>

sorry about that.

> IPv4 routers to talk to IPv6 routers through an IPv[4-6] translator box.

Nope, perhaps not. The original version of this discussion started on
ipv6@, and was about what to do if/when a 4to6 (say a nat64 device)
translator gets a packet that would match the criteria in question.

> it was at that point that my head started to hurt....)

sorry :(

-Chris