Network Working Group IANA
Request for Comments:
1797 ISI
Category: Experimental April 1995
Class A Subnet Experiment
Status of this Memo
This document defines an Experimental Protocol for the Internet
community. This does not specify an Internet standard of any kind.
Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
Discussion
There appears to be some interest in experimenting with subnetting
the class A addresses.
There is some evidence that not all the routing software in use will
deal correctly with subnetted class A addresses. It also appears
that actual use of subnetted class A addresses may be necessary in
the not too distant future. It is suggested that conducting an
experiment now to identify and fix any software that does not
properly handle subnetted class A addresses would be useful and
important.
To further this experiment the IANA will temporarily designate the
class A network number 39 to be used in the following way:
The high order octet of the 4-octet IPv4 address is the class A
network number 39. There are two cases for low order 24 bits.
Case 1:
In the first case, the high order bit of these 24 bits is zero and
the next 15 bits are the low order 15 bits of a previously
assigned Autonomous System number (AS), as registered by a network
registry and listed in the RWhois database system.
Using the AS number in this way allows the experiment to get
underway quickly in that it automatically allocates some addresses
to each service provider and does not require a registration step.
One concern is that this might cause a run on AS numbers, since by
getting an AS number you automatically get some address space.
This concern should be offset by the fact that the amount of
address space one gets under this plan is the same as one class C
The support for DNS name and address resolution should be provided.
For example, if Alternet wanted to put up a database of interesting
information using the hostname "Interesting.Alter.Net" using the
address 39.2.189.7, they would need to put the name to address
mapping in their name server using the A record
Interesting.Alter.Net. IN A 39.2.189.7
Similarly, the address to name PTR record should be supported
7.189.2.39.IN-ADDR.ARPA. PTR Interesting.Alter.Net.
which means that the 189.2.39 branch of the IN-ADDR tree would be
delegated to Alternet for the purposes of this experiment.
To support this, the 39.IN-ADDR.ARPA branch is delegated to the IANA
to be managed at ISI. The nameserver for this branch is
IN-ADDR.EP.NET (39.17.199.10). Participants in this experiment
should contact the administrator of this nameserver to have their
portion of the address space further delegated. The administrator
for this server can be reached at <aexpreg@isi.edu>.
Another aspect of the testing that should be performed is to have
providers interchange addresses to test the portability of subnetted
class A addresses. It is not intended that this would be the model
for actual use.
For example, if AS 690 and AS 1800 want to try out routing holes
in each others' allocations within their AS, that should be
encouraged. That is, suppose AS 690 handed some address of their
addresses to AS 1800, and vice-versa. This type of testing will
be necessary to see if the addresses can be made portable in
larger sub-A allocations.
This is experiment will be of limited duration and these addresses
may be reassigned to other uses when the experiment is over.
This experiment will begin on 1-May-95.
The current date for the termination of this experiment is 1-Dec-95.