Mark.Andrews;
> None of the issues hear have changed with the introduction of IPv6.
With IPv6, trancation is morelikely, which is the change.
> You have glue being dropped today because sites have excessive
> numbers of nameservers. Try asking for a really long name from
> the root servers under com or net. You may only have one glue
> record.
With your example of query for "com." all the name servers of which
are under "net." all the name servers of which are under "net.",
glues are not "necessary" that the behaviour is fine.
A problem is that the root server gives similar reply to similar
query for "vix.net".
Then, there is a subtlity whether glues are "necessary" or not.
In theory, it may be and the implementation is broken.
In practice, it may not be, if name servers do not gives up against
the obvious delegation loop (all the name servers are under zone cut)
and ask As of "?.gtld-servers.net", because query for
"?.gtld-servers.net" gives all the "necessary" glues without
truncation.
In practice with both A and AAAA, it is, because explicite query
for "?.gtld-servers.net" will also be truncated.
If the case is too difficult to understand, just consider a
case of "vix.net" with just a single AAAA and no A glue
returned. Then, IPv4 only host is at a loss.
Masataka Ohta
.
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