Intended status: Standards Track A.Eromenko January 2016
draft-eromenko-ipff-02
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draft-eromenko-ipff-02
INTERNET-DRAFT
"Internet Protocol - Five Fields",
Alexey Eromenko, 2016-01-02,
<draft-eromenko-ipff-02.txt>
expiration date: 2016-07-02
Intended status: Standards Track
A.Eromenko
January 2016
Internet Protocol, Version 5 (IPv5)
a.k.a Internet Protocol - Five Fields (IP-FF)
Specification Draft
Abstract
This document specifies version 5 of the Internet Protocol (IPv5).
a.k.a Internet Protocol Five Fields, that attempts to build a hybrid
between IPv4 and IPv6, improving on both.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
Copyright Notice
Copyright (c) 2015 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction..................................................2
1.1. Motivation..................................................
2. Terminology...................................................3
2.1. Relation to Other Protocols................................
3. IPFF Header Format............................................4
3.1. Alternative meaning: Ports or Flow Label...................
3.2. Flow-based Routing.........................................
4. IPFF Extension Headers........................................6
4.1 Extension Header Order...................................7
4.2 Options..................................................9
4.3 Hop-by-Hop Options Header...............................11
4.4 Routing Header..........................................12
4.5 Virtual Router Forwarding (VRF) extension...............
4.6 Destination Options Header..............................23
4.7 No Extension............................................24
5. Packet Size Issues...........................................24
6. Type of Service..............................................25
7. Upper-Layer Protocol Issues..................................27
7.1 Upper-Layer Checksums...................................27
7.2 Maximum Packet Lifetime.................................28
7.3 Responding to Packets Carrying Routing Headers..........29
Appendix A. Formatting Guidelines for Options...................32
Security Considerations.........................................35
Acknowledgments.................................................35
Authors' Contacts...............................................35
References......................................................35
Full Copyright Statement........................................39
1. Introduction
IP version 5 "Five Fields" (IP-FF) is a new version of the Internet
Protocol, designed as the successor to IP version 4 (IPv4) [RFC-791]
and IP version 6 [RFC-2460], combining many features of both,
removing unnecessary and adding new, and optimizing the old.
A hybrid between the two, plus plus.
The changes from IPv4 to IPFF fall primarily into the following
categories:
o Expanded Addressing Capabilities
IPFF increases the IP address size from 32 bits to 50 bits, to
support more levels of addressing hierarchy, a much greater
number of addressable nodes, yet keeping the familiar way.
That over 230,000x times more than in IPv4 and should be enough
for the next several hundred years or so...
So even if humanity grows to 100 billion people in few hundred
years from now, each can have 10,000 devices, before we deplete
our address space.
o Header Format Simplification
Some IPv4 header fields have been dropped or made optional, to
reduce the common-case processing cost of packet handling and
to limit the bandwidth cost of the IPFF header. Derived from
IPv6. IPFF goes even further by eliminating "Fragmentation",
which improves NAT-router processing speeds, and simplifies
implementations.
o Improved Support for Extensions and Options
Changes in the way IP header options are encoded allows for
more efficient forwarding, less stringent limits on the length
of options, and greater flexibility for introducing new options
in the future. Derived from IPv6.
o Virtual Router Forwarding (VRF) / Layer 3 VPN extension
o Mobile IP problem has an order of magnitude simpler solution;
see [Mobile TCP]
o Ports are at layer 3, which accelerates Flow-Based Routing,
and Firewalling decisions.
Dropped features, compared to IPv4:
o Address Resolution Protocol (ARP) now became Link Address
Resolution Algorithm (LARA). It is now computed on the CPU.
o Fragmentation, as it was proven (in IPv6) that it is cheaper to
do an MTU discovery, rather than fragment packets on each hop.
Hosts should use either MTU path discovery or fallback to 1280
MTU. In IPFF, fragmentation is completely eliminated.
This increases router processing speed and NAT performance,
and simplifies TCP/IP stack.
o IP Header checksums, as it was proven (in IPv6), that upper
layer protocols can handle it checksums and compute them
end-to-end, rather than hop-by-hop. This increases router
processing speed.
o Classes / classful networks.
o Internet Group Management Protocol, is now optional.
The changes from IPv6 to IPFF fall primarily into the following
categories:
o Human readable, simple addressing, similar to IPv4, in 5
fields. 10-bits per field. 50-bit addressing.
With 3 decimal digits in each field, and familiar dotted
decimal notation. examples: 10.0.0.0.1 and 382.201.769.25.133
o Easy migration from existing IPv4 networks.
o Improved efficiency: an IPFF packet is smaller than IPv6, at 20
bytes, same as in IPv4, saving bandwidth compared to IPv6.
o Virtual Router Forwarding (VRF) / Layer 3 VPN extension
o Mobile IP problem has an order of magnitude simpler solution;
see [Mobile TCP]
o Ports are at layer 3, which accelerates Flow-Based Routing,
and Firewalling decisions.
o Flow Labeling Capability is totally redesigned; It is now
implicit, merged with ports.
Dropped features, compared to IPv6:
o Modularization: many components, that were the "core" of IPv6
specification now became optional or eliminated.
(NDP/IGMP/MLD/SLAAC/IPsec/Flow/Fragmentation/Link-Local...)
o Fragmentation.
In IPFF, fragmentation is completely eliminated.
This increases NAT performance and simplifies TCP/IP stack.
Hosts should use either MTU path discovery or fallback to 1280
MTU.
o Link-local addresses are optional; no longer needed.
o Neighbor Discovery Protocol (NDP), divided into Link Address
Resolution Algorithm (LARA), and optional extensions.
o Stateless Auto-address configuration (SLAAC) is now optional.
Similar functionality should be provided by DHCPv5 or other
services.
o Internet Group Management Protocol, (IPv6 MLD) is now optional.
Other important changes in the IPFF stack, vs both IPv4 and IPv6:
o In UDPv5 removed "Length" field in order to reduce overhead.
o DNSv5 defines a new "AA" record type.
o New Mode: "Silent Multicast Listeners", which combines some of
the benefits of multicasts and some of the benefits of
broadcasts. In this mode, Multicast listener accepts only
traffic targeted at his IP & Layer 2 address, but does not
advertise over IGMP. In this new multicast mode, IGMP protocol
is not needed.
Details in [IPFF-ADDRARCH]
This document specifies the basic IPFF header and the initially-
defined IPFF extension headers and options. It also discusses packet
size issues, the semantics of Type of Service, and
the effects of IPFF on upper-layer protocols. The format and
semantics of IPFF addresses are specified separately in
[IPFF-ADDRARCH]. The IPFF version of ICMP, which all IPFF
implementations are required to include, is specified in [ICMPFF].
1.1. Motivation
1.1.1. Motivation: Usability
In short: Usability issues in IPv6.
IPv6 solved the scalability problems of IPv4, and simplified some
protocol details, but created a new problem.
The motivation to write a new TCP/IP stack is due to exhaustion of
IPv4 address space and also due to the "alien" nature of IPv6, where
network engineers are forced to use very-long addresses, that are
hexadecimal, hard to read & write, hard to compare, hard to memorize
and hard to debug, at least at the IP level.
Worse yet, forced link-local addresses, which adds needless
complexity. I figured, that just representing IPv6 very-long 128-bit
addresses in dotted decimal format would have not solved those
issues.
DNS (Domain Name System), while solves the usability problem at a
higher level of the stack, still leaves low level administration
issues unsolved.
Something like this:
2001:db8:2e1:1a73:149f:88ff:fe81:6116
...is absolutely not readable by a human. Not memorizable either.
1.1.2. Motivation for "Five Fields" and 50-bits
I wanted something simpler, with a look & feel akin to IPv4.
Bigger address range requirements mandated adding an additional
field. 5 fields of 8-bits would have resulted in 40-bits, ~1
trillion addresses, or x256 times bigger than IPv4. Not good enough
for the next century. This is for 15 decimal digits in human memory.
But can I do better? Well, it turns out I can.
The trick is to make it short enough so that addresses are easy to
read/compare & memorize, a problem solved by IPv4, while long enough
to handle the future requirements of the Internet, a problem solved
by IPv6.
50-bit address range theoretically gives me 5 fields of 0...1023 in
each, but to improve human reading/typing/memorizing/comparing,
the fields were limited to 3 decimal digits each.
That is range was limited to 0...999 in each field.
i.e. Address range from 0.0.0.0.0 up to 1023.1023.1023.1023.1023
was artificially limited up to 999.999.999.999.999 to improve
usability. Sacrifice of ~12.5% of available address range for the
sake of usability.
Still gives us over 230,000x times more addresses than IPv4, more
than enough for the next several centuries or so...
And this is at a cost of only 15 decimal digits.
Same as five fields of 8-bits BTW, and only 3 digits more than IPv4.
With this kind of addressing, using IP and visualizing networks in
human brain memory becomes easy again !
IP addresses, as used by millions of network engineers &
administrators on a daily basis, should be not just computer
friendly, but also human-friendly, as network engineers are humans.
1.1.3. Motivation: IPv6 is too complex
Another issue with IPv6 is that it has *too many* features,
everything including the kitchen sink. Theoretically it is
possible to design a network, that includes everything from
physical/data-link layer and up to transport, perhaps even
applications, but then it would be hard to understand, hard to
change and hard to evolve.
A monster like Neighbor Discovery Protocol (NDP) is very complex
indeed, and should be cut into pieces. Much of it's functionality
logically belongs to DHCP(or Auto-IP) and ARP, two separate pieces.
Same is true for IGMP / IPv6 MLD - unnecessary bloat, at least for
link-local Multicast implementations. Should become optional module.
Link-local addresses also add unnecessary complexity.
IPFF, in contrast, is more minimalistic, offloading features to
optional modules, allowing for simpler implementations.
IPFF also optimizes a bunch of features in new ways.
Fortunately TCP/IP (v4) protocol stack consists of digestible blocks.
P.S. I am aware that IPv5 was used for "Internet Stream Protocol" at
one point in time, but since it was not deployed, I think I can reuse
that number to indicate both "five fields" as well as a hybrid
between IPv4 and IPv6. IP-FF has nothing to do with "Internet Stream
Protocol".
"Perfection is achieved not when there is nothing more to add, but
when there is nothing left to take away". Antoine de Saint-Exupery.
2. Terminology
node - a device that implements IPFF.
router - a node that forwards IPFF packets not explicitly
addressed to itself. [See Note below].
host - any node that is not a router. [See Note below].
upper layer - a protocol layer immediately above IPFF. Examples are
transport protocols such as TCP and UDP, control
protocols such as ICMP, routing protocols such as OSPF.
link - a communication facility or medium over which nodes can
communicate at the link layer, i.e., the layer
immediately below IPFF. Examples are Ethernets (simple
or bridged); PPP links; X.25, Frame Relay, or ATM
networks; and internet (or higher) layer "tunnels",
such as tunnels over IPv4 or IPFF itself.
neighbors - nodes attached to the same link.
interface - a node's attachment to a link.
address - an IPFF-layer identifier for an interface.
packet - an IPFF header plus payload.
link MTU - the maximum transmission unit, i.e., maximum packet
size in bytes, that can be conveyed over a link.
path MTU - the minimum link MTU of all the links in a path between
a source node and a destination node.
Note: it is possible, though unusual, for a device with multiple
interfaces to be configured to forward non-self-destined packets
arriving from some set (fewer than all) of its interfaces, and to
discard non-self-destined packets arriving from its other interfaces.
Such a device must obey the protocol requirements for routers when
receiving packets from, and interacting with neighbors over, the
former (forwarding) interfaces. It must obey the protocol
requirements for hosts when receiving packets from, and interacting
with neighbors over, the latter (non-forwarding) interfaces.
2.1. Relation to Other Protocols
The following diagram illustrates the place of the internet protocol
in the protocol hierarchy:
+------+ +------+ +-----+ +-----+ +------+
| HTTP | |Telnet| | SCP | | TFTP| ... | ping |
+------+ +------+ +-----+ +-----+ +------+
| | | | |
| +-----+ +-----+ +-----+
+---------| TCP | | UDP | ... | ... |
+-----+ +-----+ +-----+
| | |
+--------------------------+----+
| Internet Protocol & ICMP |
+--------------------------+----+
|
+---------------------------+
| Local Network Protocol |
+---------------------------+
Protocol Relationships
Figure 1.
Internet protocol interfaces on one side to the higher level
host-to-host protocols and on the other side to the local network
protocol. In this context a "local network" may be a small network in
a building or a large network such as the Internet.
3. IPv5 Header Format
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4|Version| Type of Service | Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
8| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
12| Protocol | Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
16| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20| Source Port / Flow | Destination Port / Flow |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
24| Hops to Live | Extension | Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(bytes)
Version 4-bit Internet Protocol version number = 5.
Type of Service 10-bit type of service field. See section 6.
Source Address 50-bit address of the originator of the packet.
See [IPFF-ADDRARCH].
Protocol 14-bit selector. Identifies the type of protocol
or extension header immediately following the
IPFF header. Uses a similar values as the IPv4
Protocol field [RFC-1700 et seq.], but with
a wider variety.
Destination Address 50-bit address of the intended recipient of the
packet (possibly not the ultimate recipient, if
a Routing header is present).
See [IPFF-ADDRARCH] and section 4.4.
Source and Destination ports or a single Flow Label
Two 16-bit port identifiers, used by most
Transport-layer Protocols, or a single
32-bit Flow label identifier. Either way they
are used for flow-based routing purposes.
See sections 3.1 and 3.2
Hops to Live 10-bit unsigned integer. Decremented by 1 by
each node that forwards the packet. The packet
is discarded if Hops to Live is decremented to
zero.
Extension 6-bit selector. IP header extensions go here.
Zero value means "bottom-of-stack", and that
a protocol on top of IP will come next, as
specified in the "Protocol" field.
Payload Length 16-bit unsigned integer. Length of the IPFF
payload, i.e., the rest of the packet following
this IPFF header, in bytes. (Note that any
extension headers [section 4] present are
considered part of the payload, i.e., included
in the length count.)
3.1. Alternative meaning: Ports or Flow Label
Many Transport-layer protocols (including TCP, UDP, and SCTP)
require 16-bit port identifiers, so they were moved to the IP layer.
It allows to do very fast firewalling and Flow-based routing.
For some Transport-layer protocols, that do not use 16-bit Ports,
our port fields can have a different meaning: Flow Label.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
May become:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
So a complete IP header may look like this:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4|Version| Type of Service | Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
8| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
12| Protocol | Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
16| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20| Flow Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
24| Hops to Live | Extension | Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(bytes)
Despite a visual difference to the human, there is no logical
difference to the router, which is why this field
is interchangeable.
From the router's standpoint both achieve the same goal:
namely have all packets belonging to one Transport session
delivered in-order, which saves CPU time at the destination node.
Both ways, this field(s) is meant to be read-only, set by the source
node, and for the router it is Transport-layer indeterministic.
There is a difference for some middleboxes, (e.g. NAT Routers)
whom may want to write to this field, as it will trigger a
Transport-layer-specific checksum update.
Only the Transport-layer protocol decide the meaning.
Flow label can only be used by protocols, whom not use 16-bit ports.
Flow-label is meant to be a pseudo-random number set by the source
node, which, together with source and destination addresses,
specifies that same-flow packets must be forwarded through the same
path.
Some protocols may not use it at all. For example ICMP may set
both port fields to zero; which is the same as setting flow label
to zero.
3.2. Flow-based Routing
With IP-FF, the router can use a 6-tuple to make Flow based
decisions in the following way:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4|Version| Type of Service | Source Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
8| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
12| Protocol | Destination Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
16| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(bytes)
Routing decision may be based on 6-tuple parameters, rather
than only "Destination address", which sorts packets correctly,
and prevents re-ordering, which is expensive to fix.
6-tuple means source + destination addresses and ports, protocol
and Type of Service (ToS).
5-tuple means the same, without ToS.
As a bonus, having 5-tuple leads to faster firewalls in IP-FF.
This 6-tuple gives us a 160-bit "virtual flow label" if you will.
It meant to be used as an implicit flow label.
Here is the procedure:
1. First packet in such a flow is routed via traditional method.
By Destination Address.
2. The 160-bit "virtual flow label" is cached in a Router's table.
3. All incoming packets matching this flow will be routed
according to the label cached earlier, via the same path.
If a link goes down, the router must invalidate a bunch of labels.
If a new link comes up, new flows may be redirected there,
existing flows typically should be kept flowing the old way.
(assuming equal-cost load-balancing)
NOTE 1: During Flow-based routing, some "Extensions" may be
relevant, including: Hop-by-Hop, Routing and VRF headers.
NOTE 2: ToS affects flow. This is useful for traffic engineering,
as this is the only field that meants to be read-write-capable,
and can change between hops along the path.
i.e. a VPN device that acts as a tunnel endpoint,
and has static 5-tuple, can give a different ToS number to two
internal Transport sessions, thus creating two flows.
In this example, ToS field is acting as a secondary "Flow label".
If some Transport layer protocol doesn't use 16-bit ports, it can
re-use those fields as an explicit flow label.
Flow-based routing decisions can happen either way, with
an explicit Flow Label or implicitly, with ports.
4. IPFF Extension Headers
In IPFF, optional internet-layer information is encoded in separate
headers that may be placed between the IPFF header and the upper-
layer header in a packet. There are a small number of such extension
headers, each identified by a distinct Protocol value. As
illustrated in these examples, an IPFF packet may carry zero, one, or
more extension headers, each identified by the Protocol field of
the preceding header:
+---------------+------------------------
| IPFF header | TCP header + data
| |
| Protocol = TCP|
| Extension = 0 |
+---------------+------------------------
+---------------+----------------+------------------------
| IPFF header | Routing header | TCP header + data
| | |
| Protocol = TCP| |
| Extension = | Extension = 0 |
| Routing | |
+---------------+----------------+------------------------
+---------------+----------------+----------------+-----------------
| IPFF header | VRF header | Routing header | TCP header + data
| | | |
| Protocol = TCP| | |
| Extension = | Extension = | Extension = 0 |
| VRF | Routing | |
+---------------+----------------+----------------+-----------------
With few exceptions, extension headers are not examined or processed
by any node along a packet's delivery path, until the packet reaches
the node (or each of the set of nodes, in the case of multicast)
identified in the Destination Address field of the IPFF header.
There, normal demultiplexing on the Protocol field of the IPFF
header invokes the module to process the first extension header, or
the upper-layer header if no extension header is present. The
contents and semantics of each extension header determine whether or
not to proceed to the Protocol. Therefore, extension headers must
be processed strictly in the order they appear in the packet; a
receiver must not, for example, scan through a packet looking for a
particular kind of extension header and process that header prior to
processing all preceding ones.
The few exceptions referred to in the preceding paragraph is the Hop-
by-Hop Options header, which carries information that must be
examined and processed by every node along a packet's delivery path,
including the source and destination nodes. The Hop-by-Hop Options
header, when present, must follow the IPFF header and VRF.
Its presence is indicated by a pre-defined value in the Extension field
of the IPFF (or VRF) header.
Another exception is the VRF extension header, which every router
along the way should must examine according to its routing protocol,
and, if VRF extension is present, but not supported by
router implementation, drop the packet.
If, as a result of processing a header, a node is required to proceed
to the Extension but the Extension value in the current header is
unrecognized by the node, it should discard the packet and send an
ICMP Parameter Problem message to the source of the packet, with an
ICMP Code value of 1 ("unrecognized Extension type encountered").
Each extension header is an integer multiple of 8 bytes long, in
order to retain 8-bytes alignment for subsequent headers. Multi-
byte fields within each extension header are aligned on their
natural boundaries, i.e., fields of width n bytes are placed at an
integer multiple of n bytes from the start of the header, for n = 1,
2, 4, or 8.
A full implementation of IPFF includes implementation of the
following extension headers:
Hop-by-Hop Options
Destination Options
The first four are specified in this document; the last two are
specified in [RFC-2402] and [RFC-2406], respectively.
In IP-FF, as in most computing architectures, byte is
defined as 8-bits.
4.1 Extension Header Order
When more than one extension header is used in the same packet, it is
recommended that those headers appear in the following order:
IPFF header
VRF header type 1
VRF header type 2
Hop-by-Hop Options header
Destination Options header (note 1)
Routing header
Authentication header (note 2)
Encapsulating Security Payload header (note 2)
Destination Options header (note 3)
No extension header (Extension = 0)
upper-layer header
note 1: for options to be processed by the first destination
that appears in the IPFF Destination Address field
plus subsequent destinations listed in the Routing
header.
note 2: additional recommendations regarding the relative
order of the Authentication and Encapsulating
Security Payload headers are given in [RFC-2406].
note 3: for options to be processed only by the final
destination of the packet.
Each extension header should occur at most once, except for the
Destination Options header which should occur at most twice (once
before a Routing header and once before the upper-layer header),
and except the VRF header, which may occur multiple times.
If the upper-layer header is another IPFF header (in the case of IPFF
being tunneled over or encapsulated in IPFF), it may be followed by
its own extension headers, which are separately subject to the same
ordering recommendations.
If and when other extension headers are defined, their ordering
constraints relative to the above listed headers must be specified.
IPFF nodes must accept and attempt to process extension headers in
any order and occurring any number of times in the same packet,
except for the VRF and Hop-by-Hop Options header which are
restricted to appear in this particular order,
immediately after an IPFF header only.
Nonetheless, it is strongly advised that sources of IPFF packets
adhere to the above recommended order until and unless subsequent
specifications revise that recommendation.
4.2 Options
Two of the currently-defined extension headers -- the Hop-by-Hop
Options header and the Destination Options header -- carry a variable
number of type-length-value (TLV) encoded "options", of the following
format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
| Option Type | Opt Data Len | Option Data
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -
Option Type 8-bit identifier of the type of option.
Opt Data Len 8-bit unsigned integer. Length of the Option
Data field of this option, in bytes.
Option Data Variable-length field. Option-Type-specific
data.
The sequence of options within a header must be processed strictly in
the order they appear in the header; a receiver must not, for
example, scan through the header looking for a particular kind of
option and process that option prior to processing all preceding
ones.
The Option Type identifiers are internally encoded such that their
highest-order two bits specify the action that must be taken if the
processing IPFF node does not recognize the Option Type:
00 - skip over this option and continue processing the header.
01 - discard the packet.
10 - discard the packet and, regardless of whether or not the
packet's Destination Address was a multicast address, send an
ICMP Parameter Problem, Code 2, message to the packet's
Source Address, pointing to the unrecognized Option Type.
11 - discard the packet and, only if the packet's Destination
Address was not a multicast address, send an ICMP Parameter
Problem, Code 2, message to the packet's Source Address,
pointing to the unrecognized Option Type.
The third-highest-order bit of the Option Type specifies whether or
not the Option Data of that option can change en-route to the
packet's final destination. When an Authentication header (from
IPsec) is present in the packet, for any option whose data may change
en-route, its entire Option Data field must be treated as zero-valued
bytes when computing or verifying the packet's authenticating value.
0 - Option Data does not change en-route
1 - Option Data may change en-route
The three high-order bits described above are to be treated as part
of the Option Type, not independent of the Option Type. That is, a
particular option is identified by a full 8-bit Option Type, not just
the low-order 5 bits of an Option Type.
The same Option Type numbering space is used for both the Hop-by-Hop
Options header and the Destination Options header. However, the
specification of a particular option may restrict its use to only one
of those two headers.
Individual options may have specific alignment requirements, to
ensure that multi-byte values within Option Data fields fall on
natural boundaries. The alignment requirement of an option is
specified using the notation xn+y, meaning the Option Type must
appear at an integer multiple of x bytes from the start of the
header, plus y bytes. For example:
2n means any 2-byte offset from the start of the header.
8n+2 means any 8-byte offset from the start of the header,
plus 2 bytes.
There is a padding option which are used when necessary to align
subsequent options and to pad out the containing header to a multiple
of 8 bytes in length. This padding option must be recognized by
all IPFF implementations:
Pad option (alignment requirement: none)
+-+-+-+-+-+-+-+-+
| 0 |
+-+-+-+-+-+-+-+-+
NOTE! the format of the Pad option is a special case -- it does
not have length and value fields.
The Pad option is used to insert one byte of padding into the
Options area of a header.
Appendix A contains formatting guidelines for designing new options.
4.3 Hop-by-Hop Options Header
The Hop-by-Hop Options header is used to carry optional information
that must be examined by every node along a packet's delivery path.
The Hop-by-Hop Options header is identified by a Extension value of
3 in the IPFF header, and has the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
. .
. Options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 8-bit selector. Identifies the type of header
immediately following the Hop-by-Hop Options
header. Uses the similar values as the IPv4
Protocol field [RFC-1700 et seq.], with extras.
...followed by 2 zeroes. (padding)
Hdr Ext Len 8-bit unsigned integer. Length of the Hop-by-
Hop Options header in 64-bit units, not
including the first 64 bits.
Options Variable-length field, of length such that the
complete Hop-by-Hop Options header is an integer
multiple of 64 bits long. Contains one or more
TLV-encoded options, as described in section
4.2.
The only hop-by-hop option defined in this document is the Pad
option specified in section 4.2.
4.4 Routing Header
The Routing header is used by an IPFF source to list one or more
intermediate nodes to be "visited" on the way to a packet's
destination. This function is very similar to IPv4's Loose Source
and Record Route option. The Routing header is identified by
a Extension value of 43 in the immediately preceding header, and has
the following format:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len | Routing Type | Segments Left |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. type-specific data .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 8-bit selector. Identifies the next extension.
Hdr Ext Len 8-bit unsigned integer. Length of the Routing
header in 8-byte units, not including the first
16 bits.
Routing Type 8-bit identifier of a particular Routing header
variant.
Segments Left 8-bit unsigned integer. Number of route
segments remaining, i.e., number of explicitly
listed intermediate nodes still to be visited
before reaching the final destination.
type-specific data Variable-length field, of format determined by
the Routing Type, and of length such that the
complete Routing header is an integer multiple
of 8 bytes long.
If, while processing a received packet, a node encounters a Routing
header with an unrecognized Routing Type value, the required behavior
of the node depends on the value of the Segments Left field, as
follows:
If Segments Left is zero, the node must ignore the Routing header
and proceed to process the Protocol in the packet, whose type
is identified by the Protocol field in the Routing header.
If Segments Left is non-zero, the node must discard the packet and
send an ICMP Parameter Problem, Code 0, message to the packet's
Source Address, pointing to the unrecognized Routing Type.
If, after processing a Routing header of a received packet, an
intermediate node determines that the packet is to be forwarded onto
a link whose link MTU is less than the size of the packet, the node
must discard the packet and send an ICMP Packet Too Big message to
the packet's Source Address.
4.5 Virtual Router Forwarding (VRF) extension, type 1
Proposed Extension number = 1. (to be assigned by IANA)
VRFs are basically a layer-3 equivalent of IEEE 802.1q VLANs.
VRF extension header should be used together with a VRF-compatible
routing protocol to form multiple routing tables and multiple
firewall tables, each for one VRF instance. This allows enterprises
and internet service providers using Layer 3 VPNs to drop your
dependency on L2-VLANs and MPLS, dramatically simplifying network
architecture.
How to use those labels is dependent on the routing protocols, that
support VRF, but the general rule of thumb is to forward traffic only
inside the same zone / VRF, unless explicitly configured.
Different VRFs may have duplicate IP addresses.
Routing protocols themselves will need to be modified to support
IP-VRFs, and to allow VRF trunking (i.e. sync of multiple VRF tables
via one routing process).
The VRF header is used by an IPFF to encapsulate a layer-3 virtual
private network information, similarly to an dot1q VLANs of layer-2
and to Multi-Protocol Label Switching (MPLS) labels, that can form
layer-3 VPNs, when combined with the right routing protocols.
A stacking multiple VRF extensions is possible, like Q-in-Q VLAN
encapsulation.
The type 1 VRF header has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4| Extension | Virtual Router Forwarding label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
8| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(bytes)
Extension 8-bit selector. Identifies the next extension.
Virtual Router Forwarding label.
24-bit selector. Described an Enterprise-wide
L3 VPN unique number, allowing to form
layer 3 VPNs, without dot1q VLANs or MPLS.
Reserved field Must be set to zero on transmit; ignored on
receive, unless specified otherwise by a
routing protocol. Optionally may be used as
an additional flow, ToS, or hops count.
If a node or a router receives a packet with a VRF header and doesn't
know how to handle it, (for example, if VRF not configured), it
should discard it.
VRF label is mutable, and can be changed by any router along the way.
A single VRF packet leakage, due to a random bit swap in VRF label
field, is believed not to pose a security threat.
Recommended values:
0 = not enabled, same as "global VRF", should be treated the same as
packet without VRF header.
1 = admin domain. Recommended to be used for management interfaces
only for network equipment and embedded electronics.
4.5.1. Virtual Router Forwarding (VRF) extension, type 2
Proposed Extension number = 2. (to be assigned by IANA)
This is similar to the above type 1, but adds the often needed
information on the originating router (whom encapsulated into VRF,
and destination Router, that is supposed to decapsulate from VRF).
VRF header type 2 provides more information to Routing Protocols,
which may improve routing efficiency, and emulate MPLS cloud
more closely, at a heavier overhead cost.
Also VRF range is extended to full 32-bits.
The type 2 VRF header has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4| Extension | Reserved | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
8| Encapsulating Router Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
12| Reserved | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
16| Decapsulating Router Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
20| Virtual Router Forwarding label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
24| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
(bytes)
Extension 8-bit selector. Identifies the next extension.
Encapsulating Router 50-bit. This is an IP address of the router that
first encapsulated the packet into VRF instance.
A source IP/ingress of a VRF cloud, basically.
Decapsulating Router 50-bit. This is an IP address of the router that
is supposed to decapsulate the packet from VRF
instance. A destination IP/egress of a VRF
cloud, basically.
Virtual Router Forwarding label.
32-bit selector. Described an Enterprise-wide
L3 VPN unique number, allowing to form
layer 3 VPNs, without dot1q VLANs or MPLS.
Reserved fields Must be set to zero on transmit; ignored on
receive, unless specified otherwise by a
routing protocol. Optionally may be used as
an additional flow, ToS, or hops count.
If a node or a router receives a packet with a VRF header and
doesn't know how to handle it, (for example, if VRF not configured),
it should discard it. Otherwise it is a security issue.
Unlike type 1 VRF, an "ICMP Destination Unreachable" should be sent
with code "VRF table unreachable" to the Encapsulating Router.
4.6 Destination Options Header
The Destination Options header is used to carry optional information
that need be examined only by a packet's destination node(s). The
Destination Options header is identified by a Extension value of 4
in the immediately preceding header, and has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
. .
. Options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 8-bit selector. Identifies the next extension.
Hdr Ext Len 8-bit unsigned integer. Length of the
Destination Options header in 64-bit units, not
including the first 64 bits.
Options Variable-length field, of length such that the
complete Destination Options header is an
integer multiple of 8 bytes long. Contains one
or more TLV-encoded options, as described in
section 4.2.
The only destination option defined in this document is the Pad
option specified in section 4.2.
Note that there are two possible ways to encode optional destination
information in an IPFF packet: either as an option in the Destination
Options header, or as a separate extension header. The Authentication
header are examples of the latter
approach. Which approach can be used depends on what action is
desired of a destination node that does not understand the optional
information:
o If the desired action is for the destination node to discard
the packet and, only if the packet's Destination Address is not
a multicast address, send an ICMP Unrecognized Type message to
the packet's Source Address, then the information may be
encoded either as a separate header or as an option in the
Destination Options header whose Option Type has the value 11
in its highest-order two bits. The choice may depend on such
factors as which takes fewer bytes, or which yields better
alignment or more efficient parsing.
o If any other action is desired, the information must be encoded
as an option in the Destination Options header whose Option
Type has the value 00, 01, or 10 in its highest-order two bits,
specifying the desired action (see section 4.2).
4.7 No Extension
The value 0 in the Extension field of an IPv5 header or any
extension header indicates "Bottom-of-Stack", and that "Protocol"
data starts after this point.
5. Packet Size Issues
IPFF requires that every link in the internet have an MTU of 1280
bytes or greater. On any link that cannot convey a 1280-byte
packet in one piece, link-specific fragmentation and reassembly must
be provided at a layer below IPFF.
Links that have a configurable MTU (for example, PPP links [RFC-
1661]) must be configured to have an MTU of at least 1280 bytes; it
is recommended that they be configured with an MTU of 1500 bytes or
greater, to accommodate possible encapsulations (i.e., tunneling).
From each link to which a node is directly attached, the node must be
able to accept packets as large as that link's MTU.
It is strongly recommended that IPFF nodes implement Path MTU
Discovery [RFC-4821] similarly to IPv6, but at Transport Layer,
in order to discover and take advantage of path MTUs greater
than 1280 bytes.
However, a minimal IPFF implementation (e.g., in a boot ROM) may
simply restrict itself to sending packets no larger than 1280
bytes, and omit implementation of Path MTU Discovery.
6. Type of Service
The 10-bit Type of Service field in the IPFF header is available for
use by originating nodes and/or forwarding routers to identify and
distinguish between different classes or priorities of IP-FF packets.
Type of Service bits provide various forms of "differentiated
service" for IP packets.
This is similar to The "Traffic Class" field in the IPv6 header,
and to "Type of Service"/Precedence in IPv4.
The following general requirements apply to the Type of Service field:
o The service interface to the IPFF service within a node must
provide a means for an upper-layer protocol to supply the value
of the Type of Service bits in packets originated by that upper-
layer protocol. The default value must be zero for all 10 bits.
o Nodes that support a specific (experimental or eventual
standard) use of some or all of the Type of Service bits are
permitted to change the value of those bits in packets that
they originate, forward, or receive, as required for that
specific use. Nodes should ignore and leave unchanged any bits
of the Type of Service field for which they do not support a
specific use.
o An upper-layer protocol must not assume that the value of the
Type of Service bits in a received packet are the same as the
value sent by the packet's source.
In flow-based routing, ToS affects flow as part of the 6-tuple.
See "flow-based routing" for details.
7. Upper-Layer Protocol Issues
7.1 Upper-Layer Checksums
Any transport or other upper-layer protocol that includes the
addresses from the IP header in its checksum computation must be
modified for use over IPFF, to include the 50-bit IPFF addresses
instead of 32-bit IPv4 addresses. In particular, the following
illustration shows the TCP and UDP "pseudo-header" for IPFF:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | |
+-------------------------Source Address +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | |
+----------------------Destination Address +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port | Destination Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Upper-Layer Packet Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
o If the IPFF packet contains a Routing header, the Destination
Address used in the pseudo-header is that of the final
destination. At the originating node, that address will be in
the last element of the Routing header; at the recipient(s),
that address will be in the Destination Address field of the
IPFF header.
o The Protocol value in the pseudo-header identifies the
upper-layer protocol (e.g., 6 for TCP, or 17 for UDP). It will
differ from the Protocol value in the IPFF header if there
are extension headers between the IPFF header and the upper-
layer header.
o Ports should be included by protocols, that use them.
Else zero.
o The Upper-Layer Packet Length in the pseudo-header is the
length of the upper-layer header and data (e.g., TCP header
plus TCP data).
Protocols (such as TCP and UDPv5) do not carry their own
length information, in which case the length used in the
pseudo-header is the Payload Length from the IPFF header, minus
the length of any extension headers present between the IPFF
header and the upper-layer header.
The IPFF version of ICMP [ICMPFF] includes the above pseudo-header in
its checksum computation; this is a change from the IPv4 version of
ICMP, which does not include a pseudo-header in its checksum. The
reason for the change is to protect ICMP from misdelivery or
corruption of those fields of the IPFF header on which it depends,
which, unlike IPv4, are not covered by an internet-layer checksum.
The Protocol field in the pseudo-header for ICMP contains the
value 58, which identifies the IPFF version of ICMP.
7.2 Maximum Packet Lifetime
Typically up to 1023 hops (= jumps between Routers).
This is done to prevent routing loops.
Unlike IPv4, IPFF nodes are not required to enforce maximum packet
lifetime, that is "Hops to Live" field may be left unchanged by
the router, if the operator or the routing protocol decides so.
7.3 Responding to Packets Carrying Routing Headers
When an upper-layer protocol sends one or more packets in response to
a received packet that included a Routing header, the response
packet(s) must not include a Routing header that was automatically
derived by "reversing" the received Routing header UNLESS the
integrity and authenticity of the received Source Address and Routing
header have been verified (e.g., via the use of an Authentication
header in the received packet). In other words, only the following
kinds of packets are permitted in response to a received packet
bearing a Routing header:
o Response packets that do not carry Routing headers.
o Response packets that carry Routing headers that were NOT
derived by reversing the Routing header of the received packet
(for example, a Routing header supplied by local
configuration).
o Response packets that carry Routing headers that were derived
by reversing the Routing header of the received packet IF AND
ONLY IF the integrity and authenticity of the Source Address
and Routing header from the received packet have been verified
by the responder.
Appendix A. Formatting Guidelines for Options
[ this section is similat to IPv6 specification ]
Designing new options to be used in the Hop-by-Hop Options header or
the Destination Options header, as described in section 4.2. These
guidelines are based on the following assumptions:
o One desirable feature is that any multi-byte fields within the
Option Data area of an option be aligned on their natural
boundaries, i.e., fields of width n bytes should be placed at
an integer multiple of n bytes from the start of the Hop-by-
Hop or Destination Options header, for n = 1, 2, 4, or 8.
o Another desirable feature is that the Hop-by-Hop or Destination
Options header take up as little space as possible, subject to
the requirement that the header be an integer multiple of 8
bytes long.
o It may be assumed that, when either of the option-bearing
headers are present, they carry a very small number of options,
usually only one.
These assumptions suggest the following approach to laying out the
fields of an option: order the fields from smallest to largest, with
no interior padding, then derive the alignment requirement for the
entire option based on the alignment requirement of the largest field
(up to a maximum alignment of 8 bytes). This approach is
illustrated in the following examples:
Example 1
If an option X required two data fields, one of length 8 bytes and
one of length 4 bytes, it would be laid out as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Option Type=X |Opt Data Len=12|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ 8-byte field +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Its alignment requirement is 8n+2, to ensure that the 8-byte field
starts at a multiple-of-8 offset from the start of the enclosing
header. A complete Hop-by-Hop or Destination Options header
containing this one option would look as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len=1 | Option Type=X |Opt Data Len=12|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ 8-byte field +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Example 2
If an option Y required three data fields, one of length 4 bytes,
one of length 2 bytes, and one of length 1 byte, it would be laid
out as follows:
+-+-+-+-+-+-+-+-+
| Option Type=Y |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Opt Data Len=7 | 1-byte field | 2-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Its alignment requirement is 4n+3, to ensure that the 4-byte field
starts at a multiple-of-4 offset from the start of the enclosing
header. A complete Hop-by-Hop or Destination Options header
containing this one option would look as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len=1 | Pad1 Option=0 | Option Type=Y |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Opt Data Len=7 | 1-byte field | 2-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PadN Option=1 |Opt Data Len=2 | 0 | 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Example 3
A Hop-by-Hop or Destination Options header containing both options X
and Y from Examples 1 and 2 would have one of the two following
formats, depending on which option appeared first:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len=3 | Option Type=X |Opt Data Len=12|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ 8-byte field +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PadN Option=1 |Opt Data Len=1 | 0 | Option Type=Y |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Opt Data Len=7 | 1-byte field | 2-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PadN Option=1 |Opt Data Len=2 | 0 | 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Hdr Ext Len=3 | Pad1 Option=0 | Option Type=Y |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Opt Data Len=7 | 1-byte field | 2-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PadN Option=1 |Opt Data Len=4 | 0 | 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0 | 0 | Option Type=X |Opt Data Len=12|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 4-byte field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ 8-byte field +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Security Considerations
If some devices along the path do not implement VRF properly,
it can result in data leak across VRF domains.
Additionally a version of IPsec for IP-FF will provide IP-level
encryption for those, who need it.
A separate specification will be written on it.
Acknowledgments
Based on the hard work of "Stephen E. Deering" & "Robert M. Hinden",
from IPv6 project, as well as all previous TCP/IP developers
from DARPA.
While this document is largely based on [RFC-2460], forget not that
the difference in D.N.A. between humans and monkeys is just 1%.
Authors' Contacts
Alexey Eromenko
Israel
Skype: Fenix_NBK_
EMail: al4321@gmail.com
Facebook: https://www.facebook.com/technologov
References
[ICMPFF] "ICMP for the Internet Protocol Five Fields" by
Alexey.E.
[IPFF-ADDRARCH] "IP Five Fields Addressing Architecture" by Alexey.E.
[RFC-4821] M. Mathis, J. Heffner, "Packetization
Layer Path MTU Discovery", RFC 4821, March 2007.
[RFC-791] Postel, J., "Internet Protocol", STD 5, RFC 791,
September 1981.
[RFC-2460] S. Deering, R. Hinden "Internet Protocol, Version 6",
December 1998.
[RFC-1700] Reynolds, J. and J. Postel, "Assigned Numbers", STD 2,
RFC 1700, October 1994. See also:
http://www.iana.org/numbers.html
INTERNET-DRAFT
Alexey
expiration date: 2016-07-02