North American Network Operators Group
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Re: Spain was offline

  • From: Michael . Dillon
  • Date: Thu Aug 31 11:23:09 2006 
> You seem to be suggesting that ISPs run stealth slaves for these 
> kinds of zones. 

Not really. In today's world such simplistic solutions 
don't work.

> For zones that are being made available on anycast servers, ISPs may 
> be able to lobby/pay the zone operator to install an anycast instance 
> in their network. However, in general, the days of ISPs being able to 
> set these things up on their own and see benefit from them are past, 
> in my opinion.

I believe that there are still some things that ISPs can
do which cannot simply be bought on the market. For instance,
most ISPs runs simple caching servers for their DNS queries
where they keep any responses for a short time before deleting
them. It's so simple that it is built into DNS relays as an
option. 

An ISP could run a modified DNS relay that replicates all
responses to a special cache server which does not time out
the responses and which is only used to answer queries when
specified domains are unreachable on the Internet.

For instance, if you specified that all .es responses were
to be replicated to the cache and that your DNS relay should
divert queries to the cache when .es nameservers are *ALL* 
unreachable, then the impact of this type of outage is greatly
reduced. You could specify important TLDs to be cached this way
as well as important domains like google.com and yahoo.com.
The actual data cached would only be data that *YOUR* customers
are querying anyway. In fact, you could specify that any domain
which receives greater than x number of queries per day should
be cached in this way.

The volume of data cached would be so small in todays terms that
it only needs a low-end 1U (or single blade) server to handle 
this.

Since nothing like this exists on the market, the only way
for ISPs to do this is to roll their own. Of course, it is
likely that eventually someone will productize this and then
you simply buy the box and plug it in. But for now, this is the
type of thing that an ISP has to set up on their own.

--Michael Dillon