lookup
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The first case is where the DNS already provides a lookup capability
for the type of information being sought after. For example: Mail
Exchanger (MX) records specify how mail to a particular domain ...
... The second case is where the DNS does not provide an appropriate
lookup capability, but there is some widely accepted convention for
finding this information. Some use has been made of Text (TXT)
[RFC-1035 ...
... Services (WKS)
[RFC-1035] lookup capability, which makes it possible to determine
the network services offered at a given domain name ...
... information such as organization name, location, and business type.
It is hoped that one or more of these will eventually make it
possible to augment the basic lookup service which the DNS provides
with a more generalized search ...
... spoofing" attacks, and it cannot be
guaranteed that the result returned by a DNS lookup is indeed the
genuine information. Spoofing may take the form of denial of
service ...