Subject: (ngtrans) isatap-03

From: Alain Durand <[email-masked]>
Date: Thu, 14 Feb 2002 16:59:45 -0800

I have two questions/comments for the ISATAP authors

1. WKS. Isatap proposes to use WKS records in DNS.
    What is the current status of support for WKS in the
     various DNS servers/resolver in use today?

2. Phasing out ISATAP.
     Section 6.1
     "the host MAY discontinue the 'Route Polling Process'
      I'm worried that this is not strong enough and we may end up
      with many hosts still using ISATAP when native IPv6 is available.
      I'm curious to see why stronger wording like SHOULD or MUST
      was not used.

    - Alain.

---

From: "Dave Thaler" <[email-masked]>
Date: Fri, 15 Feb 2002 08:38:12 -0800

> We originally specified this as "SHOULD" but it was relaxed to "MAY"
> based on peer review input. I believe one of the other authors could
> speak better to this particular issue.

It definitely shouldn't say MUST, since we know of good reasons to keep
doing ISATAP when native IPv6 is available, and this was discussed at
the interim meeting in Seattle.  Specifically, in a site with a mix
of v4-only routers and v4/v6 routers, using ISATAP to talk to other
nodes in the site that are only reachable via ISATAP distributes the
encapsulation/decapsulation load by putting it on the hosts rather
than the ISATAP router(s).  Not using ISATAP to talk to other nodes in
the site that are only reachable via ISATAP puts lots of extra load on
the routers.  Pushing the complexity to the edge is generally seen as a
good thing.

Normal address selection rules result in packets only using ISATAP when
that's all the other end has.

-Dave

---

From: Alain Durand <[email-masked]>
Date: Fri, 15 Feb 2002 09:07:45 -0800

>that's all the other end has.

This would then argue for a SHOULD instead of a MAY.

	- Alain.

--