NAPTR record
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... adhere to. It does not define the reasons the rewrite is used, what
the expected outcomes are, or what they are used for. Those are
specified by applications that define how they use the NAPTR record
and algorithms within their contexts ...
... A 16-bit unsigned integer specifying the order in which the NAPTR
records MUST be processed to ensure the correct ordering of
rules. Low numbers are processed before high numbers, and once a
NAPTR ...
... A 16-bit unsigned integer that specifies the order in which NAPTR
records with equal "order" values SHOULD be processed, low
numbers being processed before high numbers. This is similar to
the preference field in an MX record, and is used so domain ...
... terminal lookup.
This means that this NAPTR record is the last one and that the
flag determines what the next stage should be. The "S" flag
means that the next lookup ...
...
The list of "valid" protocols for any given NAPTR record is any
protocol that implements some or all of the services defined for
...
... services of the application
* how it is to appear in the NAPTR record (i.e., the string id
of the protocol)
...
... algorithm where the output of one rewrite is a new key that points to
another rule. This looping algorithm allows NAPTR records to
incrementally specify a complete rule. These incremental rules can
be delegated which allows other entities to specify rules so that one
...
... starts with a string and some known key (domain).
NAPTR records for this key are retrieved, those with unknown Flags or
inappropriate Services are discarded and the remaining records are
...
... NAPTR, the actual domain-name is specified by the
various fields in the NAPTR record. In this case the client isn't
asking a question but is instead attempting to get at information
...
... queries with NO transformations. Any
given NAPTR record may result in a domain-name to be used for SRV
...
... NAPTR works. The reasons for the rewrite and the expected
output and its use are specified by documents that define what
applications the NAPTR record and algorithm are used for. Any
document that defines such an application must define the following:
...
... Uniform Resource
Name Resolver Discovery System. This example details how a
particular URN would use the NAPTR record to find a resolver service.
...
... 'known' key in the NAPTR algorithm. The NAPTR records for
cid.urn.arpa looked up and return a single record:
...
... probe to DNS is for more NAPTR records where the new domain is '
gatech.edu' and the string is the same string as before.
...
... prefix,
"http", and lookup NAPTR records for http.uri.arpa. This might
return a record of the form
...
... Applying this pattern to the URL extracts "www.foo.com". Looking up
NAPTR records for that might return:
...
... A non-URI example is the ENUM application which uses a NAPTR record
to map an e.164 telephone number to a URI ...
... For this example telephone number we might get back the following
NAPTR records:
...
...
The packet format for the NAPTR record is:
...
... SRV records. Since there is no place for a
port specification in the NAPTR record, when the "A" flag is used the
specified protocol must be running on its default port.
...
... A client MUST process multiple NAPTR records in the order
specified by the "order" field, it MUST NOT simply use the first
record that provides a known protocol and service ...
... The values for the Services field will be determined by the
application that makes use of the NAPTR record. Those values must be
specified in a published specification and approved by the IESG.
...
... The interactions with DNSSEC are currently being studied. It is
expected that NAPTR records will be signed with SIG records once the
DNSSEC ...