[sig-policy] prop-061-v001: 32-bit ASNs for documentation purposes

[Randy Bush <randy@psg.com>]

Dear SIG members

The proposal '32-bit ASNs for documentation purposes' has been sent to
the Policy SIG for review. It will be presented at the Policy SIG at
APNIC 26 in Christchurch, New Zealand, 25-29 August 2008.

The proposal's history can be found at:

     http://www.apnic.net/policy/proposals/prop-061-v001.html

We invite you to review and comment on the proposal on the mailing list
before the meeting.

The comment period on the mailing list before an APNIC meeting is an
important part of the policy development process. We encourage you to
express your views on the proposal:

     - Do you support or oppose this proposal?

     - Does this proposal solve a problem you are experiencing? If so,
       tell the community about your situation.

     - Do you see any disadvantages in this proposal?

     - Is there anything in the proposal that is not clear?

     - What changes could be made to this proposal to make it more
       effective?

randy and jian


________________________________________________________________________

prop-061-v001: 32-bit ASNs for documentation purposes
________________________________________________________________________



Author:     Philip Smith
            pfs@cisco.com

            Gaurab Raj Upadhaya
            gaurab@lahai.com

Version:   1

Date:      14 July 2008



1.  Introduction
----------------

This document discusses the requirement to reserve 32-bit ASNs for the
sole purpose of assisting the creation of Internet related
documentation.


2.  Summary of current problem
------------------------------

For 32-bit ASNs, the AS space above 65535 (or 1.0 in "dot" notation)
is either reserved for future use or allocated, with no portion of the
space available for documentation purposes.

Authors often need to include example address space and AS numbers
when documenting the Internet and the configuration of equipment used
in the operation of the Internet.

Authors currently use Internet resources from a variety of sources.
The following examples describe typical example usage of such Internet
resource:


     1. Using private address space and/or private AS space

        RFC 1918 [1] address space is often used for documentation
        requiring the use of IPv4 address space.  It's not ideal, but
        given that the addresses look like the rest of IPv4 address
        space, and that it is an ISP BCP to filter private addresses
        out of Internet announcements, its use protects against
        cut-and-paste accidents.

        The AS range 64512 to 65534 [2] is often used for documentation
        requiring the use of 16-bit AS numbers.  Most ISPs
        automatically filter private ASNs out of the AS path as they
        announce them to the Internet, so the use of private ASNs for
        documentation is not normally a problem.


     2. Resources reserved for documentation purposes

        RFC 3849 [3] describes an IPv6 address block which can be used
        exclusively for documentation purposes.


     3. Using Internet resources from their employer.

        This is easy to do, and this resource is typical of that which
        is routed on the Internet.


     4. Using Internet resources of a typical network on the Internet.

        Quite often the resources of the larger and more commonly known
        ISPs are used in examples.


     5. Easy to remember address values and ASNs are used.

        Typical examples might be 1.1.1.1, 2.2.2.2, AS100, AS2.4 and so
        on.  Quite often these resources are from existing allocations.


     6. Resources from ranges unassigned/unallocated at the time the
        documentation is written have been used.

        For example, ASNs above 48000, or the network 222/8 address
        block have been used.


There are two major problems with the last four options above:

     - Readers, especially those who are learning about the Internet,
       do tend to cut and paste the configuration examples onto running
       equipment.  Quite often this lab equipment is connected to a
       live production network, causing confusion and disruption to the
       innocent network used in the example.  The Internet today is a
       serious commercial entity with the vast majority of business
       participating in it attributing a serious portion of their
       annual revenue to business done over the net.  Dealing with a
       denial of service attack caused by an innocent cut and paste by
       a student of the industry has in the past caused major revenue
       loss for some organisations this has the potential to reoccur in
       the future.

     - Using address and AS space which is unused at the time the
       documentation is written means that at some stage in the near
       future the examples can disrupt real live networks, as has just
       been discussed in the previous point.


3.   Situation in other RIRs
----------------------------

The RIRs currently have no formal common policy for making a 32-bit
ASN allocation exclusively for documentation purposes.


4.    Details of the proposal
-----------------------------

It is proposed that:

     4.1 APNIC set aside a common block of 32-bit ASNs to be used
	solely for the purpose of documentation.


     4.2 The 32-bit ASN block for documentation include four ASNs.

	This is sufficient for a small network topology to include
	either exclusive 32-bit ASN or a mixture of 16-bit or 32-bit
	ASNs for purposes of documenting relationships between ASNs.


5.   Advantages and disadvantages of the proposal
-------------------------------------------------

Advantages:

    - Authors of documentation and Internet books no longer have to use
      32-bit ASNs which belong to their employer (and risk causing
      disruption to their employers business), or using 32-bit ASNs
      allocated to random organisations around the Internet (and risk
      causing disruption to a multitude of organisations).

Disadvantages:

     - Acceptance of this proposal will mean that four 32-bit ASNs will
       be added to the non-routable ASN space of the Internet.  The
       four 32-but ASNs will need to be added to the existing AS_PATH
       filter list used by all ISPs, in the same way that RFC 1918 and
       RFC 3849 address space should never appear on the public
       Internet.

     - Acceptance of this proposal could potentially make some people
       believe that this ASN block is effectively private ASN space as
       it is not routable.

     - If this proposal is rejected, authors will have to carry on with
       the practice highlighted in the Background section of this
       proposal, with the associated risks to the integrity of the
       commercial Internet.


6.   Effect on APNIC members
----------------------------

This proposal has no direct effect on APNIC members.

7.   Effect on NIRs
-------------------

This proposal has no direct effect on NIRs.


8.   References
---------------

[1] RFC 1918, Address Allocation for Private Internets
       http://www.ietf.org/rfc/rfc1918.txt

[2] Autonomous System (AS) Numbers,
       http://www.iana.org/assignments/as-numbers

[3] RFC 3849, IPv6 Address Prefix Reserved for Documentation
       http://www.ietf.org/rfc/rfc3849.txt

-30-