RR
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... A specific method for entering and retrieving RRs which map
between network names and numbers. ...
... do not because of indifference or errors on the part of system
administrators when maintaining the database. The WKS RR is an
example. Thus, while we favor distribution as a general method, we
...
...
Two types of information are stored here: PTR RRs which point
to the network name in their data sections, and A RRs ...
... RRs which point
to the network name in their data sections, and A RRs, which
are present if the network (or subnet ...
... network (or subnet) is subnetted further.
If a type A RR is present, then it has the address mask as its
data. The general form is:
...
... different file from that which holds the information below
IN-ADDR.ARPA. Similar PTR RRs can be used at subnet names.
...
...
The data here is one or more PTR RRs pointing at the
IN-ADDR.ARPA names corresponding to host ...
...
The first RR states that the organization named ARPA owns net 10 (It
might also own more network ...
... might also own more network numbers, and these would be represented
with an additional RR per net.) The second states that the network
name ARPANET ...
...
Then the following RRs would be entered in ISI's master file for the
ISI.EDU zone:
...
... When the network entry is located, do a lookup for a possible A RR.
If the A RR is found, look up the next level of subnet ...
... lookup for a possible A RR.
If the A RR is found, look up the next level of subnet using the
original IP address ...
... subnet using the
original IP address and the mask in the A RR. Repeat this procedure
until no A RR is found.
...
... A 255.255.255.0
2. Since an A RR was found, repeat using mask from RR
(255.255.255.0), constructing a query ...
...
2. Since an A RR was found, repeat using mask from RR
(255.255.255.0), constructing a query for
...
... A 255.255.255.240
3. Since another A RR was found, repeat using mask
255.255.255.240 (x'FFFFFFF0'). constructing a query for
...
... IN-ADDR.ARPA. PTR inc-subsubnet.isi.edu.
4. Since no A RR is present at 16.2.9.128.IN-ADDR.ARPA., there
are no more subnet ...
... Thus the mapping between 23 and TELNET is represented by a pair of
PTR RRs, one for each direction of the mapping.
...
...
Another possibility would be to shorten the RDATA section of the RRs
which map back and forth by deleting the origin. This could be done
either by allowing the domain name ...
... RDATA portion to not
identify a real domain name, or by defining a new RR which used a
simple text string rather than a domain name.
...