[address-policy-wg] Policy Change Request - Allow address allocations for anycast DNS operation

On Wed, 9 Jun 2004, Andreas Bäß/Denic wrote:
> So far I think the original would serve RIPE and the DNS operators needs:
> 
> "Operators providing DNS for a zone that is approaching the UDP packet
> size limit due to the number of authoritative servers may be assigned
> PI network prefixes: a /24 IPv4 prefix and/or a /32 IPv6 prefix. These
> prefixes will allow them to anycast the DNS server, as described in RFC
> 3258."

No, this completely misses Joao's point which spelled out that you
don't get an allocation unless you will anycast it.  For example, my
private company shouldn't be able to get PI prefixes just by adding 20
authorative DNS servers!

In other words, either you're creating PI space for ccTLDs (or some
other groups, whether special or not), or you're creating PI space for
anycasting for certain applications, or both.  This needs to be made
clearer as different people have different assumptions here.

That said, I still don't think this policy makes sense.  How many
servers would that need to be?  A lot.  What prevents from anycasting
a regular PA prefix among those parties which have the largest amount
of servers?  Nothing (prefix filters based on RIPE DB shouldn't be a
problem, just add the AS of anyone anycasting to the prefix right?).

> > Also, pardon me asking but would the request be for a /24 per server to
> > be anycasted of a /24 per zone administrator?
> 
> One /24 per zone operator. I remember that someone (was that you?) would 
> like to have /24 for putting the administrative interface of the anycast 
> instances into another AS but as far as I recall there have not been much
> support for that idea.

This is unacceptable for redundancy reasons.  If the routing for the
/24 hiccups (e.g., someone advertises the prefix but drops the
packets), all the nameservers will down for people behind that ISP?  
If you anycast something, there will have to be a backup option as
well.

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings