Hosting multiple TLDs

[Jonathan de Boyne Pollard]

JdeBP> That is _good_ practice.  _Best_ practice is for all of the
JdeBP> intermediate domain names to be subdomains of the domain being
JdeBP> delegated itself.  [...] The reason for this is that it allows
JdeBP> server softwares such as BIND, "tinydns", and Microsoft's DNS
JdeBP> server to continually refresh the cached delegation information
JdeBP> with each response that they send.

MA> Actually they don't cache this information.  

BIND might not, but it's myopic of a content DNS server administrator
to think that the only servers that will query his/her content DNS 
servers will be BIND.  The whole of Internet doesn't use BIND by a 
long shot.  Other server softwares _do_ cache this information, and 
benefit from having their caches refreshed in the way that I described.  

MA> It would be nice if they could but too many administators fail 
MA> to turn off / update the old servers when they make changes in 
MA> the delegation.  This leads to server lock.  

This is a problem that is best dealt with by educating content DNS 
server administrators in the correct way to move their services, 
not by having server softwares discard information that they 
could usefully cache.

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/dns-switching-content-servers.html#ChangingOld>