Subject: Re: (ngtrans) An IPv4 anycast address for 6to4<->6bone gateways

From: Keith Moore <[email-masked]>
Date: Thu, 02 Nov 2000 11:37:26 -0500

> Each new anycast address means additional routing entries in the
> default-free zone.  Personally I'm not sure whether the ability to
> have a standard IPv4 address for the 6to4/6bone gateways is enough to
> justify this (the current Web page is a good alternative). 

I don't think that the cost of a single extra entry in the routing table
is so great, especially since it could do a lot to make IPv6 deployment
easier.  And as compared to the web page, the anycast approach has the 
advantages that it requires little or no manual configuration (it can 
be the default) and that it can automatically adapt to changing network
conditions.

Keith
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From: Simon Leinen <[email-masked]>
Date: 02 Nov 2000 11:02:27 +0100

>>>>> "bh" == Brad Huntting <[email-masked]> writes:
> 6to4 gateways would advertise to the their IPv4 peers that they have
> a route for "a.b.c.d".  And for their IPv6 peers (the 6bone) they
> can advertise a route for 2002::/16.

> Does anyone see a problem with this?  I dont suppose there's already
> a block of IPv4 address space set aside for anycast?

I think nobody has really been using IPv4 anycast on a global
(inter-provider) scale.  The IETF dnsop working group is conducting an
experiment on global anycast, with the possible application of name
servers for important zones such as the root, see
draft-ietf-dnsop-ohta-shared-root-server-00.txt
(http://www.switch.ch/lan/dns/references.html#aroot for a pointer).

Each new anycast address means additional routing entries in the
default-free zone.  Personally I'm not sure whether the ability to
have a standard IPv4 address for the 6to4/6bone gateways is enough to
justify this (the current Web page is a good alternative).  One might
be tempted by the idea that making global IPv4 routing more difficult
would be a good thing to promote the deployment of IPv6, but this
could also backfire.

Regards,
-- 
Simon.