Internet DRAFT - draft-mdt-softwire-map-encapsulation
draft-mdt-softwire-map-encapsulation
Internet Engineering Task Force T. Murakami, Ed.
Internet-Draft IP Infusion
Intended status: Standards Track O. Troan
Expires: July 30, 2012 cisco
S. Matsushima
SoftBank
January 27, 2012
MAP Encapsulation (MAP-E) - specification
draft-mdt-softwire-map-encapsulation-00
Abstract
This document specifies the "Mapping of Address and Port" (MAP)
encapsulation based solution (MAP-E) with an automatic tunneling
mechanism for providing IPv4 connectivity service to end users over a
service provider's IPv6 network.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on July 30, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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include Simplified BSD License text as described in Section 4.e of
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 4
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. MAP-E Configuration . . . . . . . . . . . . . . . . . . . . . 5
5. MAP-E Node Behavior . . . . . . . . . . . . . . . . . . . . . 5
5.1. Provisioning of MAP-E BR . . . . . . . . . . . . . . . . . 5
5.2. Packet Forwarding Behavior on MAP-E BR . . . . . . . . . . 6
5.3. Provisioning of MAP-E CE . . . . . . . . . . . . . . . . . 7
5.4. Packet Forwarding Behavior on MAP-E CE . . . . . . . . . . 8
6. Deriving IPv6 address from IPv4 . . . . . . . . . . . . . . . 9
6.1. Deriving IPv6 address from IPv4 Address and Port
Number at the BR . . . . . . . . . . . . . . . . . . . . . 9
6.2. Deriving IPv6 address from IPv4 Address and Port
Number at the CE . . . . . . . . . . . . . . . . . . . . . 10
7. Encapsulation and Fragmentation Considerations . . . . . . . . 10
8. Packet Forwarding Considerations . . . . . . . . . . . . . . . 11
8.1. Mesh model . . . . . . . . . . . . . . . . . . . . . . . . 12
8.2. Hub & Spoke model . . . . . . . . . . . . . . . . . . . . 12
9. NAT Considerations . . . . . . . . . . . . . . . . . . . . . . 12
10. ICMP Considerations . . . . . . . . . . . . . . . . . . . . . 12
11. Security Considerations . . . . . . . . . . . . . . . . . . . 13
12. IANA Consideration . . . . . . . . . . . . . . . . . . . . . . 14
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
14.1. Normative References . . . . . . . . . . . . . . . . . . . 14
14.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
MAP-E is a protocol mechanism of the &ldque;Mapping of Address and
Port" (MAP) encapsulation based solution to deploy IPv4 to sites via
a service provider's (SP's) IPv6 network with the automatic tunneling
mechanism (IPv4-in-IPv6). Similar to Dual-Stack Lite
[I-D.ietf-softwire-dual-stack-lite], MAP-E is designed to allow IPv4
traffic to be delivered over an IPv6 network without the direct
provisioning of IPv4 addresses. Like 6rd [RFC5969], MAP-E is
operated in a fully stateless manner within the SP network.
MAP-E relies on IPv6 and is designed to deliver production-quality
dual-stack service while allowing IPv4 to be phased out within the SP
network. The phasing out of IPv4 within the SP network is
independent of whether the end user disables IPv4 service or not.
Further, &ldque;Greenfield&ldque; IPv6-only networks may use MAP-E in
order to deliver IPv4 to sites via the IPv6 network in a way that
does not require protocol translation between IPv4 and IPv6.
MAP-E utilizes an algorithmic mapping, defined in MAP
[I-D.mdt-softwire-mapping-address-and-port], between the IPv6 and
IPv4 addresses that are assigned for use within the SP network. This
mapping can provide automatic determination of IPv6 tunnel endpoints
from IPv4 destination addresses, allowing the stateless operation of
MAP-E. MAP-E views the IPv6 network as a link layer for IPv4 and
supports an automatic tunneling abstraction similar to the Non-
Broadcast Multiple Access (NBMA) [RFC2491] model.
The MAP algorithmic mapping is also used to automatically provision
IPv4 addresses and allocating a set of non-overlapping ports for each
MAP-E CE. The "SP-facing" (i.e., "WAN") side of the MAP-E CE,
operate as native IPv6 interface with no need for IPv4 operation or
support. On the "end-user-facing" (i.e., "LAN") side of a CE, IPv6
and IPv4 might be implemented as for any native dual-stack service
delivered by the SP.
A MAP-E domain consists of MAP-E Customer Edge (CE) routers and one
or more MAP-E Border Relays (BRs). IPv4 packets encapsulated by
MAP-E follow the IPv6 routing topology within the SP network between
CEs and among CEs and BRs. CE to CE traffic is direct, while BRs are
traversed only for IPv4 packets that are destined to or are arriving
from outside a given MAP-E domain. As MAP-E is stateless, BRs may be
reached using anycast for failover and resiliency.
MAP-E does not require any stateful NAPT [RFC3022] functions at the
BRs or elsewhere within the SP network. Instead, MAP-E allows for
sharing of IPv4 addresses among multiple sites by automatically
allocating a set of non-overlapping ports for each CE as part of the
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stateless mapping function. It is expected that the CE will, in
turn, perform local IPv4 Network Address and Port Translation (NAPT)
[RFC3022] functions for the site as is commonly performed today,
except avoiding ports outside of the allocated port set. Although
MAP-E is designed primarily to support IPv4 deployment to a customer
site (such as a residential home network) by an SP, it can equally be
applied to an individual host acting as a CE router.
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
3. Terminology
MAP-E: Mapping of Address and Port - Encapsulation
mode. MAP-E utilizes a simple IPv4-in-IPv6
tunneling along with the MAP extensions for
mapping between IPv4 and IPv6 defined in MAP
[I-D.mdt-softwire-mapping-address-and-port] and
this draft.
MAP-E domain (Domain): A set of MAP-E CEs and BRs connected to the
same virtual MAP-E link. A service provider
may deploy MAP-E with a single MAP-E domain, or
may utilize multiple MAP-E domains. Each
domain requires a separate MAP-E rule set.
MAP-E Border Relay (BR): A MAP-E enabled router managed by the
service provider at the edge of a MAP-E domain.
A Border Relay router has at least one of each
of the following: an IPv6-enabled interface, a
MAP-E virtual interface acting as an endpoint
for the MAP-E IPv4 in IPv6 tunnel, and an IPv4
interface connected to the native IPv4 network.
A MAP-E BR may also be referred to simply as a
"BR" within the context of MAP-E.
MAP-E Customer Edge (CE): A device functioning as a Customer Edge
router in a MAP-E deployment. In a residential
broadband deployment, this type of device is
sometimes referred to as a "Residential
Gateway" (RG) or "Customer Premises Equipment"
(CPE). A typical MAP-E CE serving a
residential site has one WAN side interface,
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one or more LAN side interfaces, and a MAP-E
virtual interface. A MAP-E CE may also be
referred to simply as a "CE" within the context
of MAP-E.
Shared IPv4 address: An IPv4 address that is shared among multiple
nodes. Each node has a separate part of the
transport layer port space.
MAP-E Rule: A MAP rule defining the mapping relationship
for a given MAP-E domain between IPv4 and IPv6,
defined in MAP
[I-D.mdt-softwire-mapping-address-and-port]
4. MAP-E Configuration
The IPv4 prefix, IPv4 address or shared IPv4 address for use at a
customer site is automatically obtained based on BMR defined in MAP
[I-D.mdt-softwire-mapping-address-and-port] from the IPv6 prefix
delegated to the site.
For a given MAP-E domain, the BR and CE MUST be configured with a set
of mapping rules (BMR, FMR and DMR) defined in
[I-D.mdt-softwire-mapping-address-and-port] . The configured values
for these elements MUST be consistent for all CEs and BRs within a
given MAP-E domain.
The configuration elements in the set of mapping rules (BMR, FMR and
DMR) may be provisioned via IPv6 DHCP defined in
[I-D.mdt-softwire-map-dhcp-option] or manually.
The only remaining provisioning information in order to enable MAP-E
is an IPv6 prefix. This IPv6 prefix is configured as part of
obtaining IPv6 Internet access (i.e., configured via SLAAC, DHCPv6,
DHCPv6 PD, manual or otherwise).
5. MAP-E Node Behavior
5.1. Provisioning of MAP-E BR
The MAP-E BR needs to be provisioned with information for the MAP-E
domain or domains it is expected to handle, along with any necessary
routing processes. For each MAP-E domain, the BR will have the
following parameters:
o The MAP Domain IPv4 and IPv6 prefix, and their lengths (Basic
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Mapping Rule)
o The MAP EA-bits (CE index), including IPv4 suffix, length and any
port-range (including any excluded ports and the port number
continuity parameter)
o The BR prefix and its length (Default Mapping Rule)
o The subnet ID
A BR when configured for BMR, FMR and DMR, and performs the following
functions:
o Configures the IPv4/IPv6 stateless encapsulation parameters (BMR,
FMR and DMR)
Based on the above configuration, the IPv4-in-IPv6 encapsulation
function can be performed by the BR.
o Derive IPv4 address along with any applicable port-range from IPv4-
translatable address (BMR)
o Derive IPv4-translatable address from IPv4 address and port number
(FMR)
5.2. Packet Forwarding Behavior on MAP-E BR
(a) BR reception of an IPv4 packet
Step 1 BR looks up an appropriate mapping rule (FMR)
with a specific Domain IPv4 prefix which has
the longest match with an IPv4 destination
address in the received IPv4 packet. If the
FMR is not found, the received packet should be
discarded. If the length of Domain IPv4 prefix
plus EA-bits associated with the FMR does not
exceed 32 bits, BR proceeds to step 2. If the
length exceeds 32 bits, BR checks that the
received packet contains a complete IPv4
datagram. If the packet is fragmented, BR
should reassemble the packet. Once BR can
obtain the complete IPv4 datagram, BR proceeds
to step 2 as though the datagram has been
received in a single packet.
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Step 2 BR generates a CE IPv6 address from the IPv4
destination address or the IPv4 destination
address and the destination port based on the
FMR found in step 1. If the CE IPv6 address
can be successfully generated, BR encapsulates
the IPv4 packet in IPv6 and forwards the IPv6
packet via the IPv6 interface. If the length
of the IPv6 encapsulated packet exceeds the MTU
of the IPv6 interface, the fragmentation should
be done in IPv6.
(b) BR reception of an IPv6 packet
Step 1 If the received IPv6 packet is fragmented, the
reassembly should be done in IPv6 at first.
Once BR obtains a complete IPv6 packet, BR
looks up an appropriate mapping rule (BMR) with
a specific Domain IPv6 prefix which has the
longest match with an IPv6 source address in
the received IPv6 packet. If the BMR rule is
not found, the received IPv6 packet should be
discarded. BR derives a CE IPv6 address from
the IPv4 source address or the IPv4 source
address and the source port in the encapsulated
IPv4 packet based on the BMR. If the CE IPv6
address is eqaul to the IPv6 source address in
the received IPv6 packet, BR decapsulates the
IPv4 packet and then forward it via the IPv4
interface.
5.3. Provisioning of MAP-E CE
A MAP-E CE requires the following parameters for provisioning:
o The MAP Domain IPv4 and IPv6 prefix, and their lengths (Basic
Mapping Rule)
o The MAP EA-bits (CE index), including IPv4 suffix, length and any
port-range (including any excluded ports and the port number
continuity parameter)
o The BR prefix and its length (Default Mapping Rule)
A MAP-E CE that receives a MAP DHCP option
[I-D.mdt-softwire-map-dhcp-option] for BMR, FMR and DMR and performs
the following (MAP initialization) functions:
o Configures the NAT44 port-range mapping function parameters (BMR)
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o Configures the IPv4/IPv6 stateless encapsulation parameters (BMR,
FMR and DMR) Based on the above configuration, the IPv4/IPv6
encapsulation function can be performed in CE.
o Derives IPv4 address along with any applicable port-range from
IPv4-translatable address (BMR)
o Derives IPv4-translatable address from IPv4 address (FMR)
5.4. Packet Forwarding Behavior on MAP-E CE
(a) CE reception of an IPv4 packet
Step 1 CE looks up an appropriate mapping rule (FMR)
with a specific Doamin IPv4 prefix which has
the longest match with an IPv4 destination
address in the received IPv4 packet. If the
FMR is found, the length of Domain IPv4 prefix
plus EA-bits must be checked. If the length
does not exceeds 32 bits, CE proceeds to step
2. If the length exceeds 32 bits, CE checks
that the received IPv4 packet contains a
complete IPv4 datagram. If the packet is
fragmented, CE should reassemble the packet.
Once CE can obtain the complete IPv4 datagram,
CE proceeds to step 2 as though the datagram
has been received in a single packet. If the
FMR is not found, CE proceeds to step 2.
Step 2 If the FMR is found in step 1, CE derives a
IPv6 destination address from the IPv4
destination address or the IPv4 destination
address and the destination port based on the
FMR. If the IPv6 destination address can be
derived successfully, CE encapsulates the IPv4
packet in IPv6 whose destination address is set
to the derived IPv6 address. If the FMR is not
found in step 1, CE uses the DMR and then CE
encapsulates the IPv4 packet in IPv6 whose
destination address is set to the BR IPv6
address. Then CE forwards the IPv6 packet via
IPv6 interface. If the length of the IPv6
packet exceeds the MTU of the IPv6 interface,
the fragmentation should be done in IPv6.
Moreover, if using IPv4 shared address, a
Datagram ID in the received IPv4 header must be
over-written before encapsulating the IPv4
packet in IPv6. In case of shared IPv4
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address, the Datagram ID must be unique among
CEs sharing the same IPv4 address. Hence, CE
should assign the unique value and set this
value to the datagram ID in IPv4 header. This
value may be generated from the port-range
assigned to the CE to keep the uniqueness among
CEs sharing same IPv4 address.
(b) CE reception of an IPv6 packet
Step 1 If the received IPv6 packet is fragmented, the
reassembly should be done in IPv6 at first.
Once CE obtains a complete IPv6 packet, CE
looks up an appropriate mapping rule (BMR) with
a specific Domain IPv6 prefix which has the
longest match with an IPv6 source address in
the recieved IPv6 packet. If the BMR is found,
the CE derives a CE IPv6 address from the IPv4
source address or the IPv4 source address and
the source port based on the BMR and then
checks that the IPv6 source address of the
received IPv6 packet is matched to it. If the
BMR is not found, CE checks that the IPv6
source address is matched to the BR IPv6
address. In case of success, the CE can
decapsulate the IPv4 packet and forward it via
the IPv4 interface.
6. Deriving IPv6 address from IPv4
6.1. Deriving IPv6 address from IPv4 Address and Port Number at the BR
IPv6 Source Address and Source Port Number:
At the BR, the IPv6 source address MUST be set to the BR IPv6 address
as per DMR MAP [I-D.mdt-softwire-mapping-address-and-port]. The
source Layer 4 port number MUST be unchanged.
IPv6 Destination Address and Destination Port Number:
At the BR, the IPv6 destination address (IPv4-translatable address)
MUST be derived from the IPv4 destination address and the destination
port number per FMR MAP [I-D.mdt-softwire-mapping-address-and-port].
The destination Layer 4 port number MUST be unchanged.
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6.2. Deriving IPv6 address from IPv4 Address and Port Number at the CE
IPv6 Source Address and Source Port Number:
At the CE, the IPv6 source address (IPv4-translatable address) MUST
be derived from the IPv4 source address as per BMR MAP
[I-D.mdt-softwire-mapping-address-and-port]. The source port number
MUST be unchanged.
IPv6 Destination Address and Destination Port Number:
At the CE, if Forwarding Mapping Rules (FMRs) are enabled, the IPv4
packet MUST be checked to see if the IPv4 destination address matches
the FMR. If matching, the IPv6 destination address (IPv4-converted
address) MUST be derived from the IPv4 destination address and the
destination port number as per FMR. Otherwise, the IPv6 destination
address MUST be set to the BR IPv6 address per DMR MAP
[I-D.mdt-softwire-mapping-address-and-port]. The destination port
number MUST be unchanged.
7. Encapsulation and Fragmentation Considerations
Maximum transmission unit (MTU) and fragmentation issues for IPv4 in
IPv6 tunneling are discussed in detail in Section 7.2 of [RFC2473].
MAP-E's scope is limited to a service provider network. IPv6 Path
MTU discovery MAY be used to adjust the MTU of the tunnel as
described in Section 7.2 of [RFC2473], or the MAP-E Tunnel MTU might
be explicitly configured.
The use of an anycast source address could lead to any ICMP error
message generated on the path being sent to a different BR.
Therefore, using dynamic tunnel MTU Section 7.2 of [RFC2473] is
subject to IPv6 Path MTU blackholes.
Multiple BRs using the same anycast source address could send
fragmented packets to the same MAP-E CE at the same time. If the
fragmented packets from different BRs happen to use the same fragment
ID, incorrect reassembly might occur. For this reason, a BR using an
anycast source address MUST NOT fragment the IPv6 encapsulated packet
unless BR's having identical rules are required to use disjoint
ranges of fragment ID.
If the MTU is well-managed such that the IPv6 MTU on the CE WAN side
interface is set so that no fragmentation occurs within the boundary
of the SP, then the MAP-E Tunnel MTU should be set to the known IPv6
MTU minus the size of the encapsulating IPv6 header (40 bytes). For
example, if the IPv6 MTU is known to be 1500 bytes, the MAP-E Tunnel
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MTU might be set to 1460 bytes. Absent more specific information,
the MAP-E Tunnel MTU SHOULD default to 1280 bytes.
Alternatively, if BR's having identical rule are required to use
disjoint ranges of fragment ID, a BR using an anycast source address
SHOULD fragment the IPv6 encapsulated packet correctly.
For MAP-E domain traversal, IPv4 packets are encapsulated in IPv6
packets whose Next header is set to 4 (i.e. IPv4). If fragmentation
of IPv6 packets is needed, it is performed according to [RFC2460].
Absent more specific information, the path MTU of a MAP-E Domain has
to be set to 1280 [RFC2460].
In domains where IPv4 addresses are not shared, IPv6 destinations are
derived from IPv4 addresses alone. Thus, each IPv4 packet can be
encapsulated and decapsulated independently of each other. MAP-E
processing is completely stateless.
On the other hand, in domains where IPv4 addresses are shared, BR's
and CE's can have to encapsulate IPv4 packets whose IPv6 destinations
depend on destination ports. Precautions are needed, due to the fact
that the destination port of a fragmented datagram is available only
in its first fragment. A sufficient precaution consists in
reassembling each datagram received in multiple packets, and to treat
it as though it would have been received in single packet. This
function is such that MAP-E is in this case stateful at the IP layer.
(This is common with DS-lite and NAT64/DNS64 which, in addition, are
stateful at the transport layer.) At Domain entrance, this ensures
that all pieces of all received IPv4 datagrams go to the right IPv6
destinations.
Another peculiarity of shared IPv4 addresses is that, without
precaution, a destination could simultaneously receive from different
sources fragmented datagrams that have the same Datagram ID (the
Identification field of [RFC0791]. This would disturb the reassembly
process. To eliminate this risk, CE MUST rewrite the datagram ID to
an unique value among CEs having same shared IPv4 address upon
sending the packets over MAP-E tunnel. This value SHOULD be
generated locally within the port-range assigned to a given CE. Note
that replacing a Datagram ID in an IPv4 header implies an update of
its Header-checksum fieald, by adding to it the one's complement
difference between the old and the new values.
8. Packet Forwarding Considerations
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8.1. Mesh model
Basically, MAP-E should allow the mesh model in order for all CEs to
communicate each others directly. If one mapping rules is applied to
a given MAP-E domain, all CEs can communicate each others directly.
If multiple mapping rules are applied to a given MAP-E domain, or if
multiple MAP-E domains are existed, CE can communicate each others
directly only if all CEs know all mapping rules. When a CE receives
an IPv4 packet from its LAN side, the CE looks up a mapping rule
corresponding to an IPv4 destination address in the received IPv4
packet. If the corresponding mapping rule is found, CE can
communicate to another CE directly based on the mapping rule defined
as Forwarding mapping rule (FMR) in
[I-D.mdt-softwire-mapping-address-and-port] . If the corresponding
mapping rule is not found, CE must forward the packet to a given BR.
8.2. Hub & Spoke model
In order to allow the mesh topology so that all CEs can communicate
each others directly, all CE should know all mapping rules applied to
a given MAP-E domain or MAP-E domains. However, if a CE knows only
subset of mapping rules applied to a given MAP-E domain or MAP-E
domains, a CE can not communicate to some CEs due to the lack of
mapping rules. In this case, an IPv4 packet toward to these CEs must
be forwarded to a given BR. In order to achieve the hub & spoke mode
fully, Forwarding mapping rule (FMR) defined in
[I-D.mdt-softwire-mapping-address-and-port] should be disabled. In
this case, all CEs do not look up the mapping rules upon receiving an
IPv4 packet from its LAN side and then CE must encapsulate the IPv4
packet with IPv6 whose destination must be a given BR.
9. NAT Considerations
NAT44 should be implemented in CPE which has MAP-E CE function. The
NAT44 must conform that best current practice documented in
[RFC4787], [RFC5508] and [RFC5382]. When there are restricted
available port numbers in a given MAP-E CE, the NAT44 must restrict
mapping ports within the port-set.
10. ICMP Considerations
ICMP message should be supported in MAP-E domain. Hence, the NAT44
in MAP-E CE must implement the behavior for ICMP message conforming
to the best current practice documented in [RFC5508].
If a MAP-E CE receives an ICMP message having ICMP identifier field
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in ICMP header, NAT44 in the MAP-E CE must rewrite this field to a
specific value assigned from the port-set. BR and other CEs must
handle this field similar to the port number in tcp/udp header upon
receiving the ICMP message with ICMP identifier field.
If a MAP-E BR and CE receives an ICMP error message without ICMP
identifier field for some errors that is detected inside a IPv6
tunnel, a MAP-E BR and CE should replay the ICMP error message to the
original source. This behavior should be implemented conforming to
the section 8 of [RFC2473]. The MAP-E BR and CE obtain the origianl
IPv6 tunnel packet storing in ICMP payload and then decapsulate IPv4
packet. Finally the MAP-E BR and CE generate a new ICMP error
message from the decapsulated IPv4 packet and then forward it.
If a MAP-E BR receives an ICMP error message on its IPv4 interface,
the MAP-E BR should replay the ICMP message to an appropriate MAP-E
CE. If IPv4 address is not shared, the MAP-E BR generates a CE IPv6
address from the IPv4 destination address in the ICMP error message
and encapsulates the ICMP message in IPv6. If IPv4 address is
shared, the MAP-E BR derives an original IPv4 packet from the ICMP
payload and generates a CE IPv6 address from the source address and
the source port in the original IPv4 packet. If the MAP-E BR can
generate the CE IPv6 address, the MAP-E BR encapsulates the ICMP
error message in IPv6 and then forward it to its IPv6 interface.
11. Security Considerations
Spoofing attacks: With consistency checks between IPv4 and IPv6
sources that are performed on IPv4/IPv6 packets
received by BR's and CE's (Section 5), MAP-E
does not introduce any opportunity for spoofing
attack that would not pre-exist in IPv6.
Denial-of-service attacks: In MAP-E domains where IPv4 addresses are
shared, the fact that IPv4 datagram reassembly
may be necessary introduces an opportunity for
DOS attacks. This is inherent to address
sharing, and is common with other address
sharing approaches such as DS-lite and NAT64/
DNS64. The best protection against such
attacks is to accelerate IPv6 enablement in
both clients and servers so that, where MAP-E
is supported, it is less and less used.
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Routing-loop attacks: This attack may exist in some automatic-
tunneling scenarios are documented in
[I-D.ietf-v6ops-tunnel-loops]. They cannot
exist with MAP-E because each BRs checks that
the IPv6 source address of a received IPv6
packet is a CE address.
Attacks facilitated by restricted port set: From hosts that are not
subject to ingress filtering of [RFC2827], some
attacks are possible by intervening with faked
packets during ongoing transport connections
([RFC4953], [RFC5961], [RFC6056]. The attacks
depend on guessing which ports are currently
used by target hosts. Using unrestricted port
set which mean that are IPv6 is exactly
preferable. To avoid this attacks using
restricted port set, NAT44 filtering behavior
SHOULD be "Address-Dependent Filtering".
12. IANA Consideration
This document makes no request of IANA.
13. Acknowledgements
This draft is based on original idea described in
[I-D.despres-softwire-sam]. The authors would like to thank Remi
Despres, Mark Townsley, Wojciech Dec and Olivier Vautrin.
14. References
14.1. Normative References
[I-D.mdt-softwire-map-dhcp-option]
Mrugalski, T., Boucadair, M., Troan, O., Deng, X., and C.
Bao, "DHCPv6 Options for Mapping of Address and Port",
draft-mdt-softwire-map-dhcp-option-01 (work in progress),
October 2011.
[I-D.mdt-softwire-mapping-address-and-port]
Troan, O., "Mapping of Address and Port (MAP)",
draft-mdt-softwire-mapping-address-and-port-01 (work in
progress), October 2011.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
Murakami, et al. Expires July 30, 2012 [Page 14]
Internet-Draft MAP Encapsulation (MAP-E) January 2012
September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998.
[RFC2491] Armitage, G., Schulter, P., Jork, M., and G. Harter, "IPv6
over Non-Broadcast Multiple Access (NBMA) networks",
RFC 2491, January 1999.
[RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C.,
and M. Carney, "Dynamic Host Configuration Protocol for
IPv6 (DHCPv6)", RFC 3315, July 2003.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006.
14.2. Informative References
[I-D.despres-softwire-sam]
Despres, R., "Stateless Address Mapping (SAM) - a
Simplified Mesh-Softwire Model",
draft-despres-softwire-sam-01 (work in progress),
July 2010.
[I-D.ietf-softwire-dual-stack-lite]
Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4
Exhaustion", draft-ietf-softwire-dual-stack-lite-11 (work
in progress), May 2011.
[I-D.ietf-v6ops-tunnel-loops]
Nakibly, G. and F. Templin, "Routing Loop Attack using
IPv6 Automatic Tunnels: Problem Statement and Proposed
Mitigations", draft-ietf-v6ops-tunnel-loops-07 (work in
progress), May 2011.
[I-D.operators-softwire-stateless-4v6-motivation]
Boucadair, M., Matsushima, S., Lee, Y., Bonness, O.,
Borges, I., and G. Chen, "Motivations for Stateless IPv4
over IPv6 Migration Solutions",
draft-operators-softwire-stateless-4v6-motivation-02 (work
in progress), June 2011.
[RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in
IPv6 Specification", RFC 2473, December 1998.
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Internet-Draft MAP Encapsulation (MAP-E) January 2012
[RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering:
Defeating Denial of Service Attacks which employ IP Source
Address Spoofing", BCP 38, RFC 2827, May 2000.
[RFC3022] Srisuresh, P. and K. Egevang, "Traditional IP Network
Address Translator (Traditional NAT)", RFC 3022,
January 2001.
[RFC4787] Audet, F. and C. Jennings, "Network Address Translation
(NAT) Behavioral Requirements for Unicast UDP", BCP 127,
RFC 4787, January 2007.
[RFC4953] Touch, J., "Defending TCP Against Spoofing Attacks",
RFC 4953, July 2007.
[RFC5382] Guha, S., Biswas, K., Ford, B., Sivakumar, S., and P.
Srisuresh, "NAT Behavioral Requirements for TCP", BCP 142,
RFC 5382, October 2008.
[RFC5508] Srisuresh, P., Ford, B., Sivakumar, S., and S. Guha, "NAT
Behavioral Requirements for ICMP", BCP 148, RFC 5508,
April 2009.
[RFC5961] Ramaiah, A., Stewart, R., and M. Dalal, "Improving TCP's
Robustness to Blind In-Window Attacks", RFC 5961,
August 2010.
[RFC5969] Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4
Infrastructures (6rd) -- Protocol Specification",
RFC 5969, August 2010.
[RFC6056] Larsen, M. and F. Gont, "Recommendations for Transport-
Protocol Port Randomization", BCP 156, RFC 6056,
January 2011.
Authors' Addresses
Tetsuya Murakami (editor)
IP Infusion
1188 East Arques Avenue
Sunnyvale
USA
Email: tetsuya@ipinfusion.com
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Internet-Draft MAP Encapsulation (MAP-E) January 2012
Ole Troan
cisco
Oslo
Norway
Email: ot@cisco.com
Satoru Matsushima
SoftBank
1-9-1 Higashi-Shinbashi, Munato-ku
Tokyo
Japan
Email: satoru.matsushima@tm.softbank.co.jp
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