Internet Engineering Task Force R. Despres
Internet-Draft RD-IPtech
Expires: August 12, 2008 February 9, 2008
IPv6 Rapid Deployment on IPv4 infrastructures (6rd)
draft-despres-v6ops-6rd-ipv6-rapid-deployment-00
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Copyright Notice
Copyright (C) The IETF Trust (2008).
Abstract
IPv6 rapid deployment (6rd) builds upon mechanisms of 6to4 (RFC3056)
to enable a service provider to rapidly deploy IPv6 unicast service
to its existing IPv4 sites. Like 6to4, it utilizes stateless IPv6 in
IPv4 encapsulation in order to transit IPv4-only network
infrastructure. Unlike 6to4, 6rd requires a service provider to use
one of its own IP prefixes rather than the fixed 6to4 prefix. A
service provider has used this mechanism for its own "rapid
deployment" of IPv6 (five weeks from first exposure to "opt-in"
deployment for 1,500,000 residential sites).
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Table of Contents
1. Introduction and 6rd purpose . . . . . . . . . . . . . . . . . 3
2. Abbreviations and terminology . . . . . . . . . . . . . . . . 5
3. 6rd specification . . . . . . . . . . . . . . . . . . . . . . 6
3.1. General principles . . . . . . . . . . . . . . . . . . . . 6
3.2. 6rd ISP prefix and 6rd addresses . . . . . . . . . . . . . 8
3.3. Encapsulation and decapsulation in 6rd CPEs and 6rd
relays . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.3.1. Packet format . . . . . . . . . . . . . . . . . . . . 9
3.3.2. 6rd prefix in non 6rd addresses - the 6rd pure
IPv6 tag . . . . . . . . . . . . . . . . . . . . . . . 10
3.3.3. Relationship between IPv6 and IPv4 addresses in
encapsulation packets . . . . . . . . . . . . . . . . 11
3.4. ICMP consideration . . . . . . . . . . . . . . . . . . . . 12
3.5. IPv4 routing precaution . . . . . . . . . . . . . . . . . 12
3.6. Pseudo code . . . . . . . . . . . . . . . . . . . . . . . 13
4. The 6rd DHCPv4 option . . . . . . . . . . . . . . . . . . . . 14
5. 6rd Applicability to ISPs that use IPv4 private addresses . . 14
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
7. Security Considerations . . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . . 17
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 18
Intellectual Property and Copyright Statements . . . . . . . . . . 19
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1. Introduction and 6rd purpose
After having had a succinct presentation of the 6rd idea, a major ISP
in France, Free Telecom, did all of the following in only five weeks
(November 7th to December 11th 2007): (1) obtain its first IPv6
prefix from its RIR; (2) make the needed 6rd software modifications
to all CPE that it provides to its customers; (3) provision a 6to4
gateway, duly modified to support 6rd; (4) test IPv6 operation with a
few applications; (6) finish deployment; (7) announce IPv6
availability, at no extra charge, for all customers accepting to have
it. More than 1,500,000 residential customers thus became able to
use IPv6 in their sites, with a look and feel as that of other native
IPv6 solutions, at the only condition to consciously activate the
function in their CPEs.
This story is not reported to suggest that other ISPs should be able
to do the same. It illustrates however that, under some
circumstances, the following vicious circle has been broken:
o ISPs that have large IPv4 installed bases tend to wait for more
customer demand before bearing the cost of generalized IPv6
support.
o Customers tend to wait for more IPv6 depending applications before
requiring IPv6 support by ISPs.
o Application developers tend to wait for more IPv6 support by ISPs
before investing substantially on IPv6 dependent applications.
6rd has been designed to drastically simplify first IPv6 deployments
on IPv4 installed infrastructures.
Ideal conditions for 6rd deployment, which were satisfied at Free,
are that:
o The ISP controls CPEs of all its sites.
o It can easily modify CPE software and have it downloaded.
o It can quickly install gateways of its own, with high bandwidth in
both IPv4 and IPv6.
o It can adapt the software of these gateways to 6rd (preferably
starting with an existing 6to4 relay software to minimize the
effort).
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A less ideal but workable situation is one where CPEs are provisioned
by customers themselves (hosts , or site entrance routers). For
these sites to benefit from 6rd being deployed by their ISP, they
need 6rd support also in their CPEs. The necessary software upgrade
then depends on their CPE vendor to implement 6rd, and to whoever
manages theses CPEs to download the new releases. The 6rd
specification is proposed to become a standard for this to be
possible.
The purpose of this draft is that, with it:
o The community of IETF experts can critically evaluate its
soundness.
o ISPs that offer only IPv4 services can determine whether, based on
their own constraints, they wish to use 6rd to accelerate their
own IPv6 deployment.
o CPE manufacturers can determine whether they wish to support 6rd
in their products. If they do, their clients whose ISPs support
6rd will have native IPv6 operational in their sites.
o Manufacturers of routers used in ISP infrastructures can determine
whether they wish to include 6rd support in their products. (Note
that in which products to do it may depend on whether address
parsing hardware is used, and on whether it is suitable for parse
6rd prefix parsing.) If they do, 6rd relays at the IPv4-IPv6
border will no longer have to be devices external to these
routers, and their number will be easily increased. The added
value will then move from external devices to these manufacturer's
routers.
Readers are supposed to be familiar with IPv6 address formats and
notation.
It is understood that the wording of this draft 00 can be much
improved, in particular with respect to the English language. But it
is also felt that presenting the 6rd to the IETF shouldn't be delayed
further, so that debates on it can start as soon as possible.
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2. Abbreviations and terminology
6rd: a mechanism for IPv6 rapid deployment by independent ISPs on
their existing IPv4 infrastructures
6rd CPE: CPE which supports 6rd (host or site entrance router)
6rd ISP: ISP which supports 6rd (operates 6rd relays)
6rd site: IPv4 customer site of a 6rd ISP
6rd ISP anycast address: IPv4 anycast address chosen by a 6rd ISP
6rd ISP prefix: IPv6 prefix chosen a 6rd ISP
6rd ISP relay: a stateless encpasulation-decapsulation function
between IPv4 and IPv6 routing infrastructures of an ISP
6to4: Connection of IPv6 Domains via IPv4 clouds [RFC3056][RFC3068]
CPE: Customer Premise Equipment (host or router at site entrance)
DHCPv4: IPv4 Dynamic Host Configuration Protocol [RFC2131]
IANA: Internet Assigned Numbers Authority
ICMPv4: IPv4 Internet Control Message Protocol [RFC0792]
ICMPv6: IPv6 Internet Control Message Protocol [RFC0792]
IPv4: Layer 3 Internet Protocol of 1981 [RFC0791]
IPv6: Layer 3 Internet Protocol version 6 [RFC2460]
ISP: Internet Service Provider
MTU: Maximum Transfer Unit [RFC1191]
NAT: Network Address Translator [RFC2663]
Pure IPv6: IPv6 with addresses that contain no IPv4 address
RIR: Regional Internet Registry
Site: Customer site (has a CPE at its entrance)
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3. 6rd specification
3.1. General principles
The 6rd specification is based on the following principles :
a. For RAPIDITY of IPv6 deployment by ISPs that are still IPv4-only,
this deployment should be feasible on their UNMODIFIED IPv4
INFRASTRUCTURES.
b. For COMPLETENESS of the IPv6 unicast service offered to their
customers, ISPs should make NO ASSUMPTION on how hosts of other
ISPs obtain their IPv6 service.
c. For SCALABILITY of IPv6 deployment on IPv4 infrastructures,
encapsulation-decapsulation functions of IPv6 packets in IPv4
ones should be STATELESS (load sharing between a number of
distributed processors should be feasible).
d. For EFFICIENCY, IPv6 packet between two IPv4 sites of a same ISP
should follow the SAME ROUTES as those of IPv4 packets between
the same sites.
The rapidity principle implies that 6rd functions should be
introduced only at the periphery of IPv4 infrastructures. Routing on
these infrastructures should be that of IPv4, with no need for an
independent address assignment and routing policy for IPv6.
The completeness principle implies that IPv6 prefixes of 6rd sites
MUST start with prefixes that belong to the IPv6 address spaces. (In
particular, the 6to4 prefix 2002::/16 would not satisfy this
principle: packets destined to a 6to4 site reach their destination
only if they come from sites where CPEs support 6to4, or from ISPs
where the 6to4 Anycast Address is routable in IPv4 to at least one
6to4 relay. Neither of these two conditions can be guaranteed by the
destination end ISP).
The scalability principle implies that encapsulation functions in 6rd
relays can find IPv4 destination addresses without depending on some
temporary states that would relate IPv4 destinations to IPv6 ones.
For this, the most straightforward approach consists in having the
IPv4 CPE address of a 6rd site explicitly contained in its IPv6
prefix. Since this approach happens to be compatible with
satisfaction of other principles, it is adopted for 6rd.
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Another implication of the scalability principle is that 6rd relays
should be reachable, across the ISP IPv4 infrastructure, at an
anycast address. Each 6rd ISP choses for this its "6rd ISP anycast
address".
The efficiency principle implies that 6rd CPEs can recognize, in
packets leaving their sites, which ones can be routed to their
destination directly across the local ISP IPv4 infrastructure (i.e.
without having to go through a 6rd relay). For this, a simple
approach consists in each 6rd ISP to chose one and only one of its
IPv6 unicast prefixes as the "6rd ISP prefix" which appears at the
start of 6rd site addresses addresses, and to have this prefix known
by 6rd CPEs.
The architecture which results from these principles is that of
Figure 1.
6rd ISP Native
______________/\_______________ IPv6
6rd / \ routing
CPEs unchanged Stateless |
| IPv4 infrastructure 6rd ISP relays |
| | | |
V V V V
___ _____________________ ___
IPv6 | | | | | |
| |--|-. .--------------|-------| |--------
|___| | \ / | |___|
Customer | \ / 6rd ISP => |
Sites | O anycast address| <= 6rd ISP
___ | / \ | ___ prefix
| | | / \ | | |
IPv6 | |--|-' '--------------|--------| |--------
|___| | | |___|
|______________________|
6rd ARCHITECTURE
Figure 1
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3.2. 6rd ISP prefix and 6rd addresses
A 6rd address is a particular case of IPv6 address, with the
following format:
<-- Link prefix -- 64 bits -->.
| |
| 16, 24 16, 8 |
| or or |<----------- 64 bits --------->.
| 32 bits 32 bits 0 bits | |
| | | | | |
| V V V | |
+---//----+------------+--//--+-------------------------------+
|"6rd ISP | IPv4 |Subnet| Interface ID |
| prefix" |Site address| ID | |
+---//----+------------+--//--+-------------------------------+
<---- Site prefix ---->
6rd ADDRESS FORMAT
Figure 2
According to the completeness principle above, the 6rd ISP prefix,
being in the first bits of the address, MUST belong to the ISP public
unicast address space.
As far as the protocol is concerned, 6rd ISP prefixes could have any
number of bits up to 32. But implementations of 6rd, necessary in
both 6rd relays and 6rd CPEs, is simpler, and more amenable hardware
implementation where appropriate, if 6rd ISP prefixes must be
multiple of 8 bits. It is therefore proposed to be a MUST in 6rd.
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The choice between /16, /24 and /32 6rd ISP prefixes depends on
whether IPv6 prefixes ISPs obtain from their RIRs are short enough:
o With /32 RIR provided prefixes, the minimum generally recommended
today for initial ISP assignments, 6rd ISPs can only assign /64
site prefixes to their 6rd customer sites. These sites are then
limited to only one IPv6 link. This is expected to be
satisfactory initially for the vast majority of residential sites,
where the number of hosts is small. But this is a real
restriction which would advantageously be avoided with RIRs
cooperation (see below).
o With /16 RIR provided prefixes, 6rd ISPs can assign /48 site
prefixes to their 6rd customer sites, i.e. prefixes the length of
which is that RIRs recommend today for all customer sites. But
RIRs may be expected to be reluctant to distribute /16s,
especially since generalized /48 prefixes are more generous than
really needed, at least initially.
o With /24 RIR provided prefixes, 6rd ISPs can assign /56 site
prefixes to their 6rd customer sites. These sites can then
support up to 256 subnets. This is expected to be more than
sufficient for the most demanding residential sites, and largely
sufficient for almost all professional sites pending deployment of
native IPv6 infrastructures.
In view of the potential of 6rd to facilitate IPv6 availability, RIRs
could be advised to consider assigning /24 prefixes to ISPs that
deploy 6rd, and to endorse that these ISPs make their first IPv6
deployments with /56s distributed to their customers.
3.3. Encapsulation and decapsulation in 6rd CPEs and 6rd relays
3.3.1. Packet format
To traverse ISP IPv4 infrastructures, IPv6 packets are encapsulated
in IPv4 ones in conformance with [RFC2893]. The IPv4 protocol field
is set to 41, as specified by IANA for this encapsulation [Protocol
Numbers].
In order to avoid that encapsulated packets would ever be subject to
IPv4 fragmentation, 6rd ISPs MUST support path MTUs of at least 1300
octets on their complete IPv4 infrastructures. (1300 = 1280, the
minimum IPv6 MTU, plus 20, the header length of the IPv4
encapsulating packet.) Fragmentation has to be avoided because of
its incompatibility with stateless functions that operate on complete
packets and that may be implemented in several distributed instances.
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3.3.2. 6rd prefix in non 6rd addresses - the 6rd pure IPv6 tag
If an ISP has only one IPv6 prefix assigned by its RIR, as typical
for a first assignment, and first uses it to deploy IPv6 in 6rd, it
should, to avoid wasting its address space, be able to also use this
same prefix to build "pure IPv6" site prefixes. (IPv6 prefixes are
"pure" if they don't contain IPv4 addresses).
If a 6rd ISP prefix has such a mixed use, CPEs must distinguish
between destinations that are 6rd addresses of the same ISP, and
other destinations. Packets having the former have to be routed
directly to their destinations across local ISP IPv4 infrastructures;
packets having the latter have to be routed toward their destinations
via 6rd ISP relays of the local ISP). To facilitate this
determination, the 6rd specification requires that all pure IPv6
addresses that start with the 6rd ISP prefix contain a special value
in lieu of the beginning of an IPv4 field, the "6rd pure IPv6 tag".
The value of this tag has to be chosen so that it never appears at
the beginning of IPv4 unicast addresses assigned by the ISP. Its
proposed binary value is 1110 (OxE in hexadecimal, 240.0.0.0/4 in
IPv4 notation), which has the desired property: IANA has reserved the
set of all 224/8 to 239/8 consecutive prefixes, i.e. the 224/4
prefix, for IPv4 multicast addresses [IPv4 addresses].
<-- Link prefix -- 64 bits -->.
| |
| "6rd pure |
| 16, 24 IPv6 tag" |
| or 32 bits 4 bits .<----------- 64 bits --------->.
| | | | |
| V V | |
+----//-----+----+-----//-----+-------------------------------+
| 6rd ISP |1110| | Interface ID |
| prefix | | | |
+----//-----+----+-----//-----+-------------------------------+
6rd PURE IPv6 ADDRESS FORMAT
Figure 3
NOTE: If an ISP wants to use hardware which works only, or better, on
octet boundaries, it MAY decide to assign pure IPv6 addresses that,
after the 6rd ISP prefix all start with OxE0 (binary 11100000). With
this restriction on assigned addresses, presence tests of the 6rd
prefix can be performed indifferently on 4 or 8 bits.
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3.3.3. Relationship between IPv6 and IPv4 addresses in encapsulation
packets
IPv6 address (source or destination) IP4 address
in an encapsulated packet in the encapsulating packet
6rd site addresses
4 bits \
+----//-----+-|--+----- | +---------------+
| 6rd ISP |not : \ | IPv4 |
| prefix |1110: / | site address |
+----//-----+----+----- | +---------------+
<-- IPv4 --- /
site address
Non 6rd site addresses
+----//-----+---------- \
| not 6rd | |
|ISP prefix | |
+----//-----+---------- | +---------------+
6rd \ | 6rd ISP |
pure IPv6 tag / |anycast address|
+----//-----+-|--+----- | +---------------+
| 6rd ISP |1110| |
| prefix | | |
+----//-----+----+----- /
4 bits
RELATIONSHIP BETWEEN IPv6 AND IPv4 ADDRESSES
IN ENCAPSULATION PACKETS OF AN ISP
Figure 4
In an encapsulating packet, IPv4 addresses, source or destination,
have the following relationship with IPv6 addresses of the
encapsulated packets, respectively source or destination:
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o If the IPv6 address starts with the 6rd ISP prefix, and if this
prefix is not followed by the 6rd pure IPv6 tag, this site prefix
is that of a 6rd site of the local ISP. The IPv4 address MUST
then be equal to the 32 bits which follow the 6rd ISP prefix in
the IPv6 site prefix.
o Contrarily, if the ISP prefix is followed by the 6rd pure IPv6
tag, or if the IPv6 address does not start with the ISP prefix,
then this address does not belong to a 6rd site of the local ISP.
These relationships MUST be implemented in encapsulation functions of
6rd relays and 6rd CPEs.
In addition, to protect against source address spoofing, 6rd CPEs and
6rd ISP relays SHOULD silently discard packets they receive that have
unrealistic source and destination addresses or unrealistic IPv4-IPv6
address relationships. The pseudo-code of Section 3.6 presents
details of these verifications.
3.4. ICMP consideration
In 6rd decapsulation functions of 6rd CPEs and 6rd relays, ICMPv4
packets that are received to signal unreachable destinations (ICMPv4
type field = 3) SHOULD be converted into ICMPv6 packets (ICMPv6 type
field = 1 and code field = 0).
For this to be possible, ISPs that support 6rd SHOULD ensure that all
routers of their IPv4 infrastructures return ICMPv4 packets long
enough to contain IPv6 source addresses of encapsulated packets.
(This is automatically the case if these routers conform to [RFC1812]
Section 4.3.2.3.)
ICMPv6 packets received by encapsulation functions of 6rd ISP relays
and 6rd CPEs are encapsulated like any other IPv6 packets.
3.5. IPv4 routing precaution
For an ISP to guarantee proper routing of IPv6 packets going from its
IPv4 sites to other ISPs, its IPv4 infrastructure SHOULD NOT accept
from other ISPs IPv4 routes that include the 6rd ISP anycast address.
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3.6. Pseudo code
Figure 5 details, in pseudo code and with intuitive notations,
encapsulation and decapsulation functions, in both 6rd ISP relays and
6rd CPEs.
CPE DECAPSULATION ISP RELAY ENCAPSULATION
IF v6Pkt = ICMPv4(Unreachable) IF Packet > 1280 Octets
THEN Forward ICMPv6(Pkt too big) THEN Return ICMPv6(Pkt too big)
ELSEIF ELSEIF (S6 <> 6rdPrf...
(IF S4 = 6rdAnycast OR S6 = 6rdPrf.Pv6Tag...)
THEN [S6 <> 6rdPrf... THEN
OR S6 = 6rdPrf.Pv6Tag...] D4 <- bits pl to pl+32 of D6
ELSE [S6 = 6rdPrf... S4 <- 6rd Anycast
AND S6 <> 6rdPrf.Pv6Tag...]) Encapsulate IPv6 packet
AND D6 = 6rdPrf.v4SiteAdd... ELSE Discard packet
THEN Decapsulate IPv6 packet |
ELSE Discard packet |
| __________________ | ______
IPv6 V | IPv4 | V | IPv6
___ |MTU at least 1300 | ___ |
| | | | | | |
--<--|---|---|--<--- ---<--|-----|---|-----|--<---
| | |<= CPE addresses | | | |
| | | | | | | 6rd
0::/0 | | | 6rd ISP anycast| | | | <= ISP prefix
=> | | | address => | | | |
-->--|---|---|-->--- --->--|-----|---|-----|-->---
|___| | | |___| |
A |__________________| A |______
| |
| |
CPE ENCAPSULATION ISP RELAY DECAPSULATION
IF packet > 180 octets IF v6Pkt = ICMPv4(unreachable)
THEN Return ICMPv6(Pkt too big) THEN Forward ICMPv6(Pkt too big)
ELSEIF S6 = 6rdPrf.Pv6Tag...) ELSEIF
IF ( D6 = 6rdPrf... S4 <> 6rdAnycast
AND D6 <> 6rdPrf.Pv6Tag...) AND S6 = 6rdPrf...
THEN D4 <- bits pl to pl+32 of D6 AND S6 <> 6rdPrf.Pv6tag...
ELSE D4 <- 6rdAnycast AND ( D6 = 6rdPrf.Pv6tag...
S4 <- v4SiteAdd OR D6 <> 6rdPrf...
ELSE Discard packet THEN Decapsulate IPv6 packet
ELSE Discard packet
PSEUDO CODE DESCRIPTION OF 6rd FUNCTIONS
(lp being the bit length of the ISP 6rd prefix)
Figure 5
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4. The 6rd DHCPv4 option
For full support of 6rd, ISPs that have sites with customer-supplied
CPEs, and suppliers of these CPEs, SHOULD support the "6rd DHCPv4
option.
With the 6rd DHCPv4 option, 6rd CPEs obtains 6rd ISP prefixes and 6rd
ISP anycast addresses, in a DHCPv4 message [RFC2131].
The proposed format for the 6rd DHCPv4 option is as follows, where nn
is a code to be assigned by IANA:
6rd prefix length
(16, 24 or 32)
Code Length |
+-----+-----+-----+-----+-----+-----+--V--+-----+-----+-----+-----+
|= nn | = 9 | 6rd ISP Prefix | pl |6rd ISP anycast address|
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
FORMAT OF THE 6rd DHCPv4 OPTION
Figure 6
5. 6rd Applicability to ISPs that use IPv4 private addresses
Some ISP support NAT functions [RFC2663] within their IPv4
infrastructures, so that they can assign IPv4 private addresses
[RFC1918] to some of their sites. These ISPs can build IPv6 6rd site
prefixes with such IPv4 addresses.
If an ISP supports several independent NAT functions (typically
because of an insufficient scalability of NAT-supporting devices), it
has to ensure, for 6rd, that address spaces behind these NATS are
disjoint .
Figure 7 presents an example where IPv4 private addresses start with
10.0.0.0/8 [RFC1918], a typical choice since other private address
prefixes leave room for less addresses.
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______________________________
| 10.x.x.x/8 addresses |
| <== |
<-----| |----->
| 6rd ISP anycast address|
6rd CPEs | ==> | 6rd relays
| |
<-----| 0.0.0.0/0 |----->
| : |
| V |
|______________________________|
|
__|__
ISP | |
IPv4 NAT |_____|
|
|
V
IPv4 public address infrastructure
EXAMPLE OF 6rd WITH ISP ASSIGNED IPV4 PRIVATE ADDRESSES
Figure 7
NOTE: This capability is another difference of scope with 6to4. It
may increase the interest of 6rd, for rapid IPv6 deployment, where
scarcity of IPv4 addresses has led ISPs to support NATs in their
infrastructures.
6. Acknowledgements
The author would like to warmly acknowledge the major contribution of
Rani Assaf to 6rd's credibility. He immediately appreciated 6rd's
potential, and made the daring decision to implement it, and to
rapidly deploy it on Free's operational network. He has also been
first to point out that 6rd ISP prefixes can also be used for IPv6
addresses other than 6rd. Patrick Grossetete made useful suggestions
on multi-subnet sites, and on 6rd anycast addresses. Mark Townsley
advised on how to proceed in IETF.
Besides these direct contributions, acknowledgments are due to a few
IPv6 confirmed experts who, when the author was still an IPv6
newcomer, taught him subtleties of IPv6. Without his past debates
with Laurent Toutain, Francis Dupont and Alain Durand, this proposal
would probably not have been possible.
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7. Security Considerations
With the specification as is, and provided all recommended behaviors
are supported, the author has identified one security risk beyond
those that are common to all of IPv6 implementations. It results
from possibilities of IPv4 address spoofing: If a 6rd site may
receive packets with IPv4 spoofed source addresses, it may also
receive, in IPv6 encapsulated packets, IPv6 spoofed source addresses.
Since this risk is generally lived with in IPv4, letting higher
layers to ensure enough security when necessary, it is expected that
it is acceptable in practice.
8. IANA Considerations
This memo implies a request to IANA for the code of the DHCPv4 6rd
option presented of Section 4.
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9. References
9.1. Normative References
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
September 1981.
[RFC0792] Postel, J., "Internet Control Message Protocol", STD 5,
RFC 792, September 1981.
[RFC1191] Mogul, J. and S. Deering, "Path MTU discovery", RFC 1191,
November 1990.
[RFC1812] Baker, F., "Requirements for IP Version 4 Routers",
RFC 1812, June 1995.
[RFC1918] Rekhter, Y., Moskowitz, R., Karrenberg, D., Groot, G., and
E. Lear, "Address Allocation for Private Internets",
BCP 5, RFC 1918, February 1996.
[RFC2131] Droms, R., "Dynamic Host Configuration Protocol",
RFC 2131, March 1997.
[RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor
Extensions", RFC 2132, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2463] Conta, A. and S. Deering, "Internet Control Message
Protocol (ICMPv6) for the Internet Protocol Version 6
(IPv6) Specification", RFC 2463, December 1998.
[RFC2893] Gilligan, R. and E. Nordmark, "Transition Mechanisms for
IPv6 Hosts and Routers", RFC 2893, August 2000.
[RFC3513] Hinden, R. and S. Deering, "Internet Protocol Version 6
(IPv6) Addressing Architecture", RFC 3513, April 2003.
9.2. Informative References
[IPv4 addresses]
Internet Assigned Numbers Authority, "Internet Protocol v4
Address Space -
http://www.nro.net/documents/pdf/nro46.pdf",
February 2008.
[Protocol Numbers]
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Internet Assigned Numbers Authority, "PROTOCOL NUMBERS -
http://www.iana.org/assignments/protocol-numbers",
January 2008.
[RFC2663] Srisuresh, P. and M. Holdrege, "IP Network Address
Translator (NAT) Terminology and Considerations",
RFC 2663, August 1999.
[RFC3056] Carpenter, B. and K. Moore, "Connection of IPv6 Domains
via IPv4 Clouds", RFC 3056, February 2001.
[RFC3068] Huitema, C., "An Anycast Prefix for 6to4 Relay Routers",
RFC 3068, June 2001.
[RIR Policy]
Number resource Organization, "RIR Comparative Policy
Overview -
http://www.iana.org/assignments/ipv4-address-space",
November 2007.
Author's Address
Remi Despres
RD-IPtech
3 rue du President Wilson
Levallois,
France
Phone: +33 6 72 74 94 88
Email: remi.despres@free.fr
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Internet-Draft 6rd - IPv6 Rapid Deployment February 2008
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