[dns-operations] Signaling client protocol to authority

[Jim Reid]

On 16 Jan 2011, at 16:44, Matthew Pounsett wrote:

> Is there a particular reason the authoritative server wouldn't just  
> look at the IP address of the client to figure it out?

The IP address sending the query to the authoritative server usually  
won't be the IP address of the end client. Their stub resolvers send  
queries to a resolving server which queries the authoritative server.