Multiple IPv4 - IPv6 address mapping encapsulation
- prefix resolution (M46E-PR)Fujitsu Limited17-25, Shinkamata 1-chome, Ota-kuTokyo144-8588Japan+81-3-3735-1111naoki.matsuhira@gmail.comIPv6IPv4This document specifies M46E Prefix Resolution (M46E-PR)
specification. M46E-PR connect IPv4 stub networks between IPv6 backbone
network. And also, M46E-PR can stack many IPv4 networks, i.e. the
nwtworks using same IPv4 private addresses without interdependence.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.This document provide M46E Prefix Resolution (M46E-PR)
specification.The basic strategy for IPv6 deployment is dual stack. However,
because of exhaustion of IPv4 address, there will be no IPv4 addresses
for configuring dual stack in near future. That means there will be IPv6
only networks automatically.However, there are many IPv4 only networks still exist and those
seems continuous use in near future. That means methods continuous use
of IPv4 network over IPv6 only network will be required.M46E-PR also provide such methots. shows network
configuration with M46E-PR. The network consists of three parts,
backbone network, stub network, and M46E-PR.Backbone network can be operated with IPv6 only. Stub network has
three cases, IPv4 only, Dual Stack (both IPv4 and IPv6), and IPv6
only.M46E-FP connects backbone network and stub network in case IPv4 still
works in that stub network. If stub network is IPv6 only, M46E-PR is not
needed.M46E-PR has mainly two function. One is IPv4 over IPv6 Encapsulation
/ Decapsulation, and another is generate a table where IPv4 stub network
belong to IPv6 network.M46E-PR excapsulates IPv4 packet to IPv6 from stub network to
backbone network, and decapsulates IPv6 packet to IPv4 from backbone
network to stub network. shows packet
format on both backbone network and stub network.M46A is a IPv6 address used in outer IPv6 header which encapsulate
IPv4 packet by M46E-PR. M46A is described in .
shows M46A address architecture.M46E address consists of three parts as follows.M46A prefix.
This value is not a fixed value, and resolved packet by packetIPv4 network plane ID is an
identifier of IPv4 network stack over IPv6 backbone network.IPv4 address in
inner IPv4 packet.M46E-PR resolve M46A using M46E Prefix Resolution Table (M46E-PR
Table). M46E-PR generate M46E-PR address resolving M46A prefix from
IPv4 network plane ID and IPv4 address. Figure show this processing.Figure show M46E-PR Table. This
table consists four parts, IPv4 network plane ID, IPv4 address,
netmask, and M46A prefix.M46E-PR configured IPv4 network plane ID, so M46E-PR know IPv4
network plane ID value the interface belongs.Resolving destination address, M46E-PR use pre-configured IPv4
network plane ID valude, and destination address of IPv4 packets, and
serch the M46E-PR table. M46E-PR table return the M46E-PR address
prefix value correspoiding IPv4 network plane ID and IPv4 destination
address. Then M46E-PR generate whole M46E-PR address.Resolving source address, M46E-PR already know IPv4 network plane
ID value and IPv6 address prefix as M46E-PR prefix. So, searching the
M46E-PR table does not require for resolving source address.M46E-PR has two working mode, one is router mode, another is host
mode.In router mode, M46E-PR act as a IPv6 router. M46E-PR occupy IPv6
subnet, and M46E-PR advertise route for M46E-PR.In host mode, M46E-PR act as a IPv6 host. M46E-PR share IPv4
subnet, that mean, M46E-PR and IPv6 hosts exists on same IPv6 subnet.
M46E-PR do proxy NDP function for IPv4 host.Figure shows sample confiuration
of M46E-PR. In this example, there are three IPv4 stub network with the
same IPv4 network plane.Figure shows M46E-PR table for
sample network.This document makes no request of IANA.Note to RFC Editor: this section may be removed on publication as an
RFC.Security Considerations does not discussed in this memo.Multiple IPv4 - IPv6 mapped IPv6 address