9 Jul
2009
9 Jul
'09
6:15 p.m.
Per Jessen wrote:
Guy Baconniere wrote:
When the query reaches the DNS of the ISP it will reply with a DNS TCP reply if minimal-responses is no (default on Bind9) or with a small UDP DSN reply if minimal-responses is yes.
I can't quite see how that would be correct. When a resolver issues a query with UDP, it will expect a reply (minimal or not) via UDP. Only if it does not get a useful answer via UDP will it change and try a TCP query.
Ah, I see that is exactly what you meant. I guess some bandwidth could be saved, but I wonder if it's worth bothering unless your DNS server is about to croak from load.
/Per
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Per Jessen, Zürich (20.6°C)