The only part of the DNS that really cares about additional
data are iterative resolvers. They can't work unless they
can get the glue they need. Every other client MUST be
able to cope with missing additional data.
Iterative resolvers only care when they can't get the glue
address records they require. In most cases a iterative
resolver can re-query for missing glue. The only time they
can't do this at the momemnt is when you have a cross
delegation.
e.g.
all the servers for a.com in b.com and all the servers
for b.com in a.com.
Note delegating servers have to take care when answering
queries for missing glue by ensuring that the glue appears
in the additional section. This should not be a problem
unless the number of nameservers is excessive.
For the cross delegation case the parent could still put the
glue record in the additional section. The iterative server
just needs to accept it as there won't be a corresponding
NS record for it.
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742 INTERNET: [EMAIL PROTECTED]
.
dnsop resources:_____________________________________________________
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