Spain was offline

Thu Aug 31 12:50:29 UTC 2006

On 31-Aug-2006, at 05:13, Michael.Dillon at btradianz.com wrote:

> Do you have your own mirrors of TLDs that are
> important to your users, i.e. .com, your .xx
> country domain, etc.?

You seem to be suggesting that ISPs run stealth slaves for these  
kinds of zones. This may have been a useful pointer for ISPs in days  
gone by, but I think today it's impractical advice.

ccTLD managers these days either already restrict zone transfers for  
privacy reasons, or are being encouraged to do so as a matter of best  
practice. Established gTLD zones like COM are sufficiently large and  
are updated so frequently that even if they were made available for  
AXFR the chances are good that most ISPs would struggle to host the  
zone, and any local instance would provide degraded service to their  
customers instead of the improvements in performance that presumably  
were the point of the exercise.

Even where zone transfers are available and ISPs are able to run  
stealth servers there is always the risk that master server ACLs (or  
the master servers themselves) will change without warning, leaving  
the stealth slave serving authoritative but stale data, which is  
guaranteed to make the helpdesk phone ring sooner or later.

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.

Joe