Error Condition
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... question posed in the query, refers the requester to another set of name
servers, or signals some error condition.
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... makes a request to a resolver which in turn sends one or more queries to
name servers and deals with the error conditions and referrals that may
result. Of course, the possible questions which can be asked in a query
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... names and addresses may combine the "name error" and "data not found"
error conditions into a single type of error return, but the general
function should not. One reason for this is that applications may ask
first for one type of information about a name followed by a second
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... Alias loops and aliases which point to
non-existent names should be caught and an error condition passed back
to the client.
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