Subject: Re: The state of IPv6 multihoming development

From: "J. Noel Chiappa" <[email-masked]>
Date: Tue, 22 Oct 2002 17:23:15 -0400

> From: "Craig A. Huegen" <[email-masked]>

    > The cost of multiple PA/CA/whateveryouwanttocallthem addresses is far
    > too much compared with the return. The complexity of multiple PA
    > prefixes across an infrastructure that has tens of thousands of subnets
    > is phenomenal from an operations perspective.

Well, there are a number of basically feasible paths you can take to support
*widescale* multi-homing. (Supporting it for just Google and a "few" other
sites is not too hard.)

First, you can use multiple connectivity-based addresses. You're saying this
is infeasible. Second, you can re-use a mobility mechanism. Third, you could
use a radical addressing architecture that assigns addresses automatically,
based on actual connectivity topology.

I don't know of any others. Do you? If not, since you don't like multiple
connectivity-based addresses, which of the other two do you prefer?

	Noel

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From: "Craig A. Huegen" <[email-masked]>
Date: Tue, 22 Oct 2002 16:50:29 -0500 (Central Daylight Time)

> connectivity-based addresses, which of the other two do you prefer?

Given those three and those three only (which is akin to asking whether
you'd be happier with a stoning, a clubbing, or being hit by a truck), the
third sounds most feasible to me.

It, however, does not align with the idea that IPv6 addresses were
intended to be globally unique and visible to the host, so several
applications would be broken.  It would require significantly complicated
machinery to be created to support, both from a routing and infrastructure
service (DNS, etc.) perspective which would delay adoption for years.  It
would most likely not address the capability of the enterprise network
operator to choose a path among the set of possible paths, as the host
would still be responsible for choosing the destination IP address,
thereby hiding the other possible paths from the infrastructure.

/cah

---
Craig A. Huegen, Chief Network Architect      C i s c o  S y s t e m s
IT Transport, Network Technology & Design           ||        ||
Cisco Systems, Inc., 400 East Tasman Drive          ||        ||
San Jose, CA  95134, (408) 526-8104                ||||      ||||
email: [email-masked]       CCIE #2100      ..:||||||:..:||||||:..