INTERNET-DRAFT K. Hubbard
InterNIC
J. Postel
IANA
M. Kosters
InterNIC
D. Conrad
APNIC
D. Karrenberg
RIPE
INTERNET REGISTRY IP ALLOCATION GUIDELINES
draft-hubbard-registry-guidelines-01.txt
Status of this Memo
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Abstract
This document describes the registry system for the distribution of
globally unique Internet address space and registry operations.
Particularly this document describes the rules and guidelines
governing the distribution of this address space.
This document replaces RFC 1466, with all the guidelines and
procedures updated and modified in the light of experience.
This document does not describe private Internet address space and
multicast address space. It also does not describe regional and local
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refinements of the global rules and guidelines.
This document can be considered the base set of operational guidelines
in use by all registries. Additional guidelines may be imposed by a
particular registry as appropriate.
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Table of Contents
1. Introduction.......................................3
2. Allocation Framework...............................4
2.1 Guidelines for Internet Service Providers.........4
2.2 Submission of Reassignment Information............7
3. Assignment Framework..............................7
3.1 Common Registry Requirements......................8
3.2 Network Engineering Plans.........................9
3.3 Previous Assignment History.......................10
3.4 Network Deployment Plans..........................10
3.5 Organization Information..........................10
3.6 Expected Utilization Rate.........................10
4. Operational Guidelines for Registries.............10
5. In-Addr.Arpa Domain Maintenance...................12
6. Right to Appeal...................................12
7. References........................................12
8. Authors' Addresses................................13
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1. Introduction
Internet address space is distributed according to the following
three goals:
1) Conservation: Fair distribution of globally unique Internet address
space according to the operational needs of the end-users and Internet
Service Providers operating networks using this address space.
Prevention of stockpiling in order to maximize the lifetime of the
Internet address space.
2) Routability: Distribution of globally unique Internet addresses
in a hierarchical manner, permitting the routing scalability of
the addresses. This scalability is necessary to ensure proper
operation of Internet routing, although it must be stressed that
routability is in no way guaranteed with the allocation or
assignment of IPv4 addresses.
3) Registration: Provision of a public registry documenting address
space allocation and assignment. This is necessary to ensure
uniqueness and to provide information for Internet trouble shooting
at all levels.
It is in the interest of the Internet community as a whole that the
above goals be pursued. However it should be noted that
"Conservation" and "Routability" are often conflicting goals. All
the above goals may sometimes be in conflict with the interests of
individual end-users or Internet service providers. Careful analysis
and judgement is necessary in each individual case to find an
appropriate compromise.
The Internet Registry system
In order to achieve the above goals the Internet Registry (IR) hierarchy
was established.
The Internet Registry hierarchy consists of the following levels of
hierarchy as seen from the top down: IANA, Regional IRs, Local IRs.
IANA
The Internet Assigned Numbers Authority has authority over all number
spaces used in the Internet. This includes Internet Address Space. IANA
allocates parts of the Internet address space to regional IRs according
to its established needs.
Regional IRs
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Regional IRs operate in large geopolitical regions such as continents.
Currently there are three regional IRs established; InterNIC serving
North America, RIPE NCC serving Europe, and AP-NIC serving the Asian
Pacific region. Since this does not cover all areas, regional IRs also
serve areas around its core service areas. It is expected that the
number of regional IRs will remain relatively small. Service areas will
be of continental dimensions.
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Regional IRs are established under the authority of the IANA. This
requires consensus within the Internet community of the region. A con-
sensus of Internet Service Providers in that region may be necessary to
fulfill that role.
The specific duties of the regional IRs include coordination and
representation of all local IRs in its respective regions.
Local IRs
Local IRs are established under the authority of the regional IR and
IANA. These local registries have the same role and responsibility as
the regional registries within its designated geographical areas. These
areas are usually of national dimensions.
2. Allocation Framework
2.1 Guidelines for Internet Service Providers (ISPs)
This document makes a distinction between the allocation of IP addresses
and the assignment of IP addresses. Addresses are allocated to ISPs by
regional registries to assign to its customer base.
ISPs who exchange routing information with other ISPs at multiple loca-
tions and operate without default routing may request space directly
from the regional registry in its geographical area. ISPs with no
designated regional registry may contact any regional registry and the
regional registry may either handle the request or refer the request to
an appropriate registry.
To facilitate hierarchical addressing, implemented using Classless
Inter-Domain Routing (CIDR), all other ISPs should request address space
directly from its upstream provider. ISPs only request address space
directly from regional registries if their immediate requirement, when
satisfied with a contiguous block allocation, has a reasonable probabil-
ity of being routable on the Internet, and they meet one or more of the
following conditions.
a) the ISP is directly connected to a major routing exchange
b) the ISP is multi-homed, that is, it has more than one
simultaneous connection to the global Internet and no
connection is favored over the other
Note that addresses issued directly from the IRs, (non-provider
based),
are the least likely to be routable across the Internet.
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The following are the IP allocation guidelines for ISPs:
1. CIDR addresses are allocated to ISPs in blocks. It is
recommended that those blocks remain intact. Fragmentation of
CIDR blocks is discouraged. More specifically, ISPs are
encouraged to treat address assignments as loans for the
duration of the connectivity provision. At the termination
of the Internet connectivity contract, e.g., the customer
moves to another service provider, it is recommended the
customer return the network addresses currently in use and
renumber into the new provider's address space. The ISP
should allow sufficient time for the renumbering process to be
completed before the IP addresses are reused.
2. To ensure efficient implementation and use of Classless
Inter-Domain Routing (CIDR), the Regional Registries issue
address space on appropriate "CIDR-supported" bit boundaries.
3. ISPs are required to utilize address space in an efficient
manner. To this end, ISPs should have documented
justification available for each assignment. The regional
registry may, at any time, ask for this information. If the
information is not available, future allocations may be impacted.
In extreme cases, existing loans may be impacted.
4. IP addresses are allocated to ISPs using a slow-start
procedure. New ISPs will receive a minimal amount based
on immediate requirement. Thereafter, allocated blocks may be
increased based on utilization verification supplied to the
regional registry. The parent registries are responsible for
determining appropriate initial and subsequent allocations.
Additional address allocations will provide enough address space
to enable the ISP to assign addresses for three months
without requesting additional address space from its parent
registry. Please note that projected customer base has little
impact on the address allocations made by the parent registries.
Initial allocation will not be based on any current or future
routing restrictions but on demonstrated requirements.
5. Due to the requirement to increase the utilization efficiency
of IPv4 address space, all assignments are made with the
assumption that sites make use of variable length subnet mask
(VLSM) and classless technologies within their network. Any
request for address space based on the use of classfull
assumptions will require a detailed justification. The use of
classfull technologies for the purposes of administrative
convenience is generally insupportable due to the limited
availability of free IPv4 address space.
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6. Regional registries may set a maximum limit on assignment sizes
such that a second opinion of the regional registry is required.
7. Due to constraints on the available free pool of IPv4 address
space, the use of static IP address assignments (e.g., one
address per customer) for dial-up users is strongly discouraged.
While it is understood that the use of static addressing may
ease some aspects of administration, the current rate of
consumption of the remaining unassigned IPv4 address space does
not permit the assignment of addresses for administrative ease.
Organizations considering the use of static IP address assignment
are expected to investigate and implement dynamic assignment
technologies whenever possible.
2.2 Submission of Reassignment Information
It is imperative that reassignment information be submitted in a prompt
and efficient manner to facilitate database maintenance and ensure
database integrity. Therefore, assignment information must be
submitted to the regional registry immediately upon making the
assignment. The following reasons necessitate transmission of the
reassignment information:
a) to provide operational staff with information on who is using
the network number and to provide a contact in case of
operational/ security problems,
b) to ensure that a provider has exhausted a majority of its
current CIDR allocation, thereby justifying an additional
allocation,
c) to assist in IP allocation studies.
Procedures for submitting the reassignment information will be
determined by each regional registry based on its unique requirements.
All sub-registries (ISPs, Local registries, etc.) must register with
their respective regional registry to receive information regarding
reassignment guidelines. No additional CIDR blocks will be
allocated by the regional registry or upstream providers until
approximately 80% of all reassignment information has been submitted.
3. Assignment Framework
An assignment is the delegation of authority over a block of IP
addresses to an end enterprise. The end enterprise will use addresses
from an assignment internally only; it will not sub-delegate those
addresses. This section discusses some of the issues involved in
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assignments and the framework behind the assignment of addresses.
In order for the Internet to scale using existing technologies, use of
regional registry services should be limited to the assignment of IP
addresses for organizations meeting one or more of the following condi-
tions:
a) the organization has no intention of connecting to
the Internet-either now or in the future-but it still
requires a globally unique IP address. The organization
should consider using reserved addresses from RFC1918.
If it is determined this is not possible, they can be
issued unique (if not Internet routable) IP addresses.
b) the organization is multi-homed with no favored connection.
c) the organization's actual requirement for IP space is
very large, for example, the network prefix required to
cover the request is of length /18 or shorter.
All other requestors should contact its ISP for address
space or utilize the addresses reserved for non-connected networks
described in RFC1918 until an Internet connection is established.
Note that addresses issued directly from the IRs,(non-provider based),
are the least likely to be routable across the Internet.
3.1 Common Registry Requirements
Because the number of available IP addresses on the Internet is limited,
the utilization rate of address space will be a key factor in network
number assignment. Therefore, in the best interest of the Internet as a
whole, specific guidelines have been created to govern the assignment of
addresses based on utilization rates.
Although topological issues may make exceptions necessary, the basic
criteria that should be met to receive network numbers are listed below:
25% immediate utilization rate
50% utilization rate within 1 year
The utilization rate above is to be used as a guideline, there may be be
occasions when the 1 year rate does not fall exactly in this range.
Organizations must exhibit a high confidence level in its 1 year utili-
zation rate and supply documentation to justify the level of confidence.
Organizations will be assigned address space based on immediate utiliza-
tion plus 1 year projected utilization. A prefix longer than /24 may be
issued if deemed appropriate. Organizations with less than 128 hosts
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will not be issued an IP address directly from the IRs. Organizations
may be issued a prefix longer than /24 if the organization can provide
documentation from a registry recognized ISP indicating the ISP will
accept the long prefix for injection into the global routing system.
Exceptions to the criteria will not be made based on insufficient equip-
ment without additional detailed justification. Organizations should
implement variable length subnet mask (VLSM) internally to maximize the
effective utilization of address space. Address assignments will be
made under the assumption that VLSM is or will be implemented.
IP addresses are valid as long as the criteria continues to be met. The
IANA reserves the right to invalidate any IP assignments once it is
determined the the requirement for the address space no longer exists.
In the event of address invalidation, reasonable efforts will be made by
the appropriate registry to inform the organization that the addresses
have been returned to the free pool of IPv4 address space.
3.2 Network Engineering Plans
Before a registry makes an assignment, it must examine each address
space request in terms of the requesting organization's networking
plans. These plans should be documented, and the following information
should be included:
1. subnetting plans, including subnet masks and number of
hosts on each subnet for at least one year
2. a description of the network topology
3. a description of the network routing plans, including the
routing protocols to be used as well as any limitations.
The subnetting plans should include:
a) a tabular listing of all subnets on the network
b) its associated subnet masks
c) the estimated number of hosts
d) a brief descriptive remark regarding the subnet.
If subnetting is not being used, an explanation why it cannot be imple-
mented is required. Care must be taken to ensure that the host and sub-
net estimates correspond to realistic requirements and are not based on
administrative convenience.
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3.3 Previous Assignment History
To promote increased usage of address space, the registries will require
an accounting of address space previously assigned to the enterprise, if
any. In the context of address space allocation, an "enterprise" con-
sists of all divisions and/or subsidiaries falling under a common parent
organization. The previous assignment history should include all net-
work numbers assigned to the organization, plus the network masks for
those networks and the number of hosts on each (sub-)network. Suffi-
cient corroborating evidence should be provided to allow the assigning
registry to be confident that the network descriptions provided are
accurate.
3.4 Network Deployment Plans
In order to assign an appropriate amount of space in the required time
frame, a registry may request deployment plans for a network. Deploy-
ment plans should include the number of hosts to be deployed per time
period, expected network growth during that time period, and changes in
the network topology that describe the growth.
3.5 Organization Information
A registry may request that an organization furnish a published descrip-
tion verifying that the organization is what it claims to be. This
information can consist of brochures, documents of incorporation, or
similar published material.
3.6 Expected Utilization Rate
As stated in the foregoing text, one of the key factors in determining
how much address space is appropriate for an organization is the
expected utilization rate of the network. The expected utilization rate
is the number of hosts connected to the network divided by the total
number of hosts possible on the network. In addition, the estimated
number of hosts should be projected over a reasonable time frame, i.e.,
one in which the requesting enterprise has a high level of confidence.
The minimal utilization rate is set by the IANA and may be changed at
any time. New utilization rates may be enforced by the regional regis-
tries prior to updating the written policy.
4. Operational Guidelines For Registries
1. Regional Registries provide registration services as its
primary function. Therefore, regional registries may charge some
fee for services rendered, generally in relation to the cost of
providing those services.
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2. Regardless of the source of its address space, sub-registries
(Local IRs, ISPs, etc.) must adhere to the guidelines of its
regional registry. In turn, it must also ensure that its
customers follow those guidelines.
3. To maximize the effective use of address space, IP addresses need
to be assigned/allocated in classless blocks. With this in mind,
assignments will not be made in Class Cs or Bs but by prefix
length. Consequently, an organization that would have been
assigned a Class B in the past will now be assigned a /16 prefix,
regardless of the actual address class.
4. All IP address requests are subject to audit and verification
by any means deemed appropriate by the regional registry.
If any assignment is found to be based on false information,
the registry may invalidate the request and return the
assigned addresses back to the pool of free addresses for
later assignment.
5. Due to technical and implementation constraints on the Internet
routing system and the possibility of routing overload, major
transit providers may need to impose certain restrictions to
reduce the number of globally advertised routes. This may
include setting limits on the size of CIDR prefixes added to
the routing tables, filtering of non-aggregated routes, etc.
Therefore, addresses obtained directly from regional registry
(provider-independent, also known as portable) are not
guaranteed routable on the Internet.
6. Information provided to request address space is often considered
sensitive by the requesting organization. The assigning
registry must treat as confidential any and all information
that the requesting organization specifically indicates as
sensitive. When a requesting organization does not have
assurance of privacy, the parent of the assigning registry may
be required to do the assignment. In such cases, the parent
registry will provide the assigning registry with information
regarding the appropriate amount of address space to allocate.
7. The transfer of IP addresses from one party to another must be
approved by the regional registries. The party trying to obtain
the IP address must meet the same criteria as if they were
requesting an IP address directly from the IR.
5. In-ADDR.ARPA Domain Maintenance
The regional registries will be responsible for maintaining IN-ADDR.ARPA
records only on the parent blocks of IP addresses issued directly to the
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ISPs or those CIDR blocks of less than /16. Local IRs/ISPs with a pre-
fix length of /16 or shorter will be responsible for maintaining all
IN-ADDR.ARPA resource records for its customers.
IN-ADDR.ARPA resource records for networks not associated with a
specific provider will continue to be maintained by the regional regis-
try.
6. Right to Appeal
If an organization feels that the registry that assigned its address has
not performed its task in the requisite manner, the organization has the
right of appeal to the parent registry.
In such cases, the assigning registry shall make available all relevant
documentation to the parent registry, and the decision of the parent
registry shall be considered final (barring additional appeals to the
parent registry's parent). If necessary, after exhausting all other
avenues, the appeal may be forwarded to IANA for a final decision.
7. References
[RFC 1519] V. Fuller, T. Li, J. Yu, K. Varadhan,
"Classless Inter- Domain Routing (CIDR): an Address
Assignment and Aggregation Strategy".
[RFC 1518] Y. Rekhter, T. Li, "An Architecture for IP
Address Allocation with CIDR".
[RFC 1918] Y. Rekhter, B. Moskowitz, D. Karrenberg, G. de Groot,
"Address Allocation for Private Internets".
[RFC 1814] E. Gerich, "Unique Addresses are Good"
[RFC 1900] B. Carpenter, Y. Rekhter, "Renumbering Needs Work"
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8. Authors' Addresses
Kim Hubbard
InterNIC Registration Services
c/o Network Solutions
505 Huntmar Park Drive
Herndon, VA 22070
Phone: (703) 742-4870
email: kimh@internic.net
Jon Postel
USC/Information Sciences Institute
4676 Admiralty Way
Marina del Rey, CA 90292
Phone: 310-822-1511
EMail: Postel@ISI.EDU
Mark Kosters
InterNIC Registration Services
c/o Network Solutions
505 Huntmar Park Drive
Herndon, VA 22070
Phone: (703) 742-4795
email: markk@internic.net
David Conrad
Asia Pacific Network Information Center
c/o United Nations University
53-70 Jingumae 5-chome,
Shibuya-ku, Tokyo 150
JP
Phone: +81-3-5467-7014
email: davidc@APNIC.NET
Daniel Karrenberg
RIPE NCC
Kruislaan 409
SJ Amsterdam NL-1098
NL
Phone: +31 20 592 5065
email: dfk@RIPE.NET
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