6to4 prefix announcements?

[Pekka Savola]

On Sun, 4 Mar 2001, Jun-ichiro itojun Hagino wrote:

>
> >It'd appear that 6to4 prefixes aren't announced on 6bone too much (I only
> >saw 2002::/16).
> >
> >Due to this, ping6 within EU<->EU takes 800 ms instead of 300 ms because
> >it must go through ipv6-router.cisco.com.
> >
> >I think this could be optimized by announcing prefixes, e.g. those
> >calculated from IPv4 addresses where IPv6 is being tested and 6to4 used.
>
> 	see RFC3056, section 5.10.  you can configure static routes to
> 	2002:xxxx:xxxx::/48 if you want to optimize it, but be sure not to
> 	announce that route.

Ah.  A new RFC. :-)

>From 5.10, I gather:

   EGP (i.e., BGP) routing will include advertisements for the 2002::/16
   prefix from relay routers into the native IPv6 domain, whose scope is
   limited by routing policy.  This is the only non-native IPv6 prefix
   advertised by BGP.

I'm rather rather depressed at the fact that within for the traffic
between two sites within EU, the chosen relay router is in the U.S.

Aren't the others (e.g. 6to4.ipv6.bt.com or 6to4.ipv6.fh-regensburg.de,
from http://www.kfu.com/~nsayer/6to4/)  announcing these at all or have
they been restricted by policy to a smaller domain?

[ I've yet to see a 6bone looking glass to see how BGP announcements look
like somewhere else too ]

This makes the whole 6to4 routing act bad.

> >Or is there reasons why this is not done?
>
> 	do you want to see 2^32 routes announced to the 6bone?

Definitely not, but I was thinking of announing them in aggregates always
bigger than traditional B-class..  With about 2^8 or 2^10 you could get
rather good connectivity already -- traffic would probably almost always
be restricted to the same continent, or a part of the continent.

This would in part transfer some routing table expansion problems of IPv4
to IPv6, which is probably the reason it's deprecated.

-- 
Pekka Savola                  "Tell me of difficulties surmounted,
Netcore Oy                    not those you stumble over and fall"
Systems. Networks. Security.   -- Robert Jordan: A Crown of Swords