Glue records (was Re: ATTN GARY KLINE)

[Jonathan McKeown]

On Friday 05 November 2010 09:28:27 Ian Smith wrote:
> But you don't always have any control of what parent nameservers do;
> eg we do DNS for a .com but both NS are in .au so DNS reports always
> whinge about lack of glue

They should be whingeing about lack of clue (their own) unless I'm horribly 
wrong about how DNS works.

When a nameserver delegates a zone, it's not responsible for any of that 
zone's records any more, with two exceptions. It provides NS records to 
indicate which nameservers /are/ responsible, and it retains responsibility 
for the A records of nameservers inside the zone - and only those 
nameservers. (That's glue.)

There's no way a .com nameserver should be providing A records for hosts in 
the .au zone.

> nonetheless it works, though only after a hunt down through the .au
> servers, until cached.

Yes, this is exactly what /should/ happen. Only the .au servers (or servers 
they delegate to) are authoritative for hosts in the .au zone.

Jonathan