Deploying IPv6 in a datacenter (Was: Awful quiet?)

Wed Dec 21 16:26:55 UTC 2005

On Wed, 21 Dec 2005, Kevin Day wrote:

> 9) Once we started publishing AAAA records for a few sites, we started getting
> complaints from some users that they couldn't reach the sites. Some
> investigating showed that they had inadvertently enabled IPv6 on their desktop
> without having any IPv6 connectivity.

I would hazard an educated guess that the majority of these users had
actually enabled 6to4 via some OS-provided convenience, which *would* work
if it weren't for (a) IPv4 NAT already widely used in "home router"
appliances, resulting in bad 2002:0a00::/24 or 2002:c0a8::/32 addresses, and
(b) many IPv6-capable providers not providing a 2002:: route, or at least
not providing a *working* one, to the 6to4 islands.

Fixing (b) would much allieviate the following when the 6to4 address in
question would otherwise be reachable:

> 11) Almost without fail, the path an IPv6 user takes to reach us (and
> vice-versa) is less optimal than the IPv4 route.

(If a user is implementing 6to4, it usually means that the v4 route *is*
better, so 6to4 becomes a routing policy suggestion as well.)

-- 
-- Todd Vierling <tv at duh.org> <tv at pobox.com> <todd at vierling.name>