Network Working Group W A Simpson
Internet Draft Daydreamer
expires in six months November 1994
IPv6 Neighbor Discovery -- ICMP Message Formats
draft-simpson-ipv6-discov-formats-01.txt |
Status of this Memo
This document is a submission to the IPng Working Group of the
Internet Engineering Task Force (IETF). Comments should be submitted
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Abstract
This document specifies ICMP messages for identification of and |
forwarding to adjacent IPv6 nodes, including Mobility, Next Hop |
Determination and Router Discovery.
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1. Additional ICMP Packets
The datagram format and basic facilities are already defined for ICMP |
as modified for IPv6 [IPv6-ICMP].
Up-to-date values of the ICMP Type field are specified in the most |
recent "Assigned Numbers" [RFC-1700]. This document concerns the
following values:
33 Where-Are-You Solicitations
34 I-Am-Here Advertisements
35 Mobile Registration Request
36 Mobile Registration Reply
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1.1. Where-Are-You Solicitations
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extensions ...
+-+-+-+-+-+-+-+-+-+-+-+-
Type 33
Code Up-to-date values are specified in the most recent |
"Assigned Numbers" [RFC-1700]. Current values are
assigned as follows:
0 RESERVED
1 General
2 Router
3 Service (reserved) |
Checksum The ICMP Checksum.
Extensions zero or more Extensions. This field is variable in |
length. The Extensions SHOULD be included in the |
order described. These Extensions are described in |
a later chapter.
The contents of the Reserved field MUST be zero on transmission, and
MUST be ignored on receipt. Future backward-compatible changes to
the protocol may specify the contents of the Reserved field or of
additional octets at the end of the message.
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1.1.1. General Solicitation
The General Solicitation MUST contain at least the following values:
Link Header (if any): |
Destination the link equivalent of the Solicited-Nodes IPv6 |
Multicast Address. The mapping is described in |
[IPv6-Address]. |
IPv6 Header:
Destination the calculated Solicited-Nodes IPv6 Multicast |
Address. The scope is intra-link. |
This is calculated by starting with the |
exclusive-or of each byte of the target IPv6 |
Unicast Address, then adding the result to the |
base Solicited-Nodes multicast (FF02::7:0). |
For example, to calculate the destination value |
for target A::B:C, the exclusive-or is E. The |
calculated destination would be FF02::7:E.
Source any IPv6 Unicast Address associated with the |
sending interface. It MUST NOT contain the
Unspecified Address. |
Hop Limit 1
ICMP fields:
Code 1 for General Solicitation.
Extensions:
Other-Identifier any IPv6 Unicast Address of the target. The |
Prefix Size and Metric are always zero. |
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU.
Media-Access for interfaces which are not point-to-point
links. |
Node-Heard for each Router Advertisement that has been
heard, in order of preference.
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In the unlikely event that not all extensions fit in a single
solicitation, as constrained by the MTU of the link, the remaining
extensions are removed.
The use of the General Solicitation is described in [D-Send]. |
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1.1.2. Router Solicitation
The Router Solicitation MUST contain at least the following values:
Link Header (if any): |
Destination the link equivalent of the All-Routers IPv6 |
Multicast Address. The mapping is described in |
[IPv6-Address]. |
IPv6 Header:
Destination the All-Routers IPv6 Multicast Address (FF02::3). |
The scope is intra-link.
Source any IPv6 Unicast Address associated with the |
sending interface. It MAY contain the
Unspecified Address, when the node has not yet |
determined an IPv6 Unicast Address. |
Hop Limit 1
ICMP fields:
Code 2 for Router Solicitation. |
Extensions: |
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU. |
Media-Access for interfaces which are not point-to-point |
links.
The use of the Router Solicitation is described in [D-Send]. |
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1.2. I-Am-Here Advertisements |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | LifeTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extensions ...
+-+-+-+-+-+-+-+-+-+-+-+-
Type 34
Code Up-to-date values are specified in the most recent |
"Assigned Numbers" [RFC-1700]. Current values are
assigned as follows:
0 RESERVED
1 General
2 Router
3 Service (reserved) |
4 Local Redirect
5 Remote Redirect
Checksum The ICMP Checksum.
Sequence Number the number of Advertisement messages sent since the |
node was initialized. The value MUST include this |
advertisement. That is, the first Advertisement
contains the value one, and the value zero indicates
that the number has rolled over.
LifeTime the seconds remaining before the advertised |
information is considered expired. The maximum time
is approximately 18.2 hours.
Extensions zero or more Extensions. This field is variable in |
length. The Extensions SHOULD be included in the |
order described. These Extensions are described in |
a later chapter.
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1.2.1. General Advertisement
The General Advertisement MUST contain at least the following values:
IPv6 Header:
Destination the Source specified in the solicitation, when |
the Source is not the Unspecified Address, the |
node is not serving several clients, and the node |
is not operating as a Mobile Node. |
Otherwise, the All-Nodes IPv6 Multicast Address |
(FF02::1). The scope is intra-link. These |
decisions are described in [D-Send] and |
[Mobility].
Source the Destination specified in the solicitation. |
Hop Limit 1
ICMP fields:
Code 1 for General Advertisement.
Lifetime the interface's configured AdvertisementLifetime.
Extensions:
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU.
Media-Access for interfaces which are not point-to-point
links.
Other-Identifier for each of that node's known IPv6 Unicast |
Addresses other than the IPv6 Unicast Address |
specified in the IPv6 Source field. The Prefix |
Size and Metric are always zero. |
This supports multiple addresses per interface, |
as well as multi-homed nodes. This enables the |
recipient node to determine the best next-hop, |
when the next-hop is on another interface |
attached to the same advertising node. |
Node-Heard for the sender of the General Solicitation. |
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In addition, each Router Advertisement that has |
been heard, in order of preference.
In the unlikely event that not all extensions fit in a single
advertisement, as constrained by the MTU of the link, the
remaining extensions are removed.
The use of the General Advertisement is described in [D-Send]. |
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1.2.2. Router Advertisement
The Router Advertisement MUST contain at least the following values:
IPv6 Header:
Destination the All-Nodes IPv6 Multicast Address (FF02::1). |
The scope is intra-link.
Source the Primary Identifier of the router. |
The same IPv6 Unicast Address is used for all |
interfaces. When a router has more than one
interface on the same link, or a multi-homed host
can hear the same router on more than one link,
it is necessary to unambiguously know which
router sent this advertisement. The individual |
cluster prefixes for the links are distinguished |
in the Routing-Information extension. |
Hop Limit 1
ICMP fields:
Code 2 for Router Advertisement.
Lifetime the interface's configured AdvertisementLifetime.
Extensions:
Hop-Limit the current Internet Time-To-Live. Up-to-date |
values are specified in the most recent "Assigned |
Numbers" [RFC-1700]. |
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU.
Media-Access for interfaces which are not point-to-point
links. |
Mobility-Support for interfaces which support Mobile Registration, |
either as a Foreign Agent or Home Agent. |
In the absence of this extension, all routers are |
expected to support decapsulation and forwarding |
from an interface, without explicit registration |
by a Mobile Node. |
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Change-Identifier for each of that interface's IPv6 Unicast or |
Cluster Addresses which has changed from a value |
previously advertised with the Routing- |
Information or Other-Identifier extensions. |
Included at least once, and repeated until the |
original LifeTime expires.
Routing-Information
for each of that interface's associated IPv6 |
Unicast Addresses whose Advertise flags are TRUE. *
Other-Identifier for each of that node's other IPv6 Unicast or |
Cluster Addresses which have not already been
included through prefix subsumption. This may be |
another address for the same interface, or may |
identify another interface on the same node. |
When a number of interfaces, such as point-to- |
point interfaces, may be aggregated with the same |
prefix, only one extension need be included. |
Node-Heard for each Router Advertisement that has been
heard, in order of preference.
In the unlikely event that not all extensions fit in a single
advertisement, as constrained by the MTU of the link, multiple
advertisements are sent, with each containing as many remaining |
extensions as can fit.
The use of the Router Advertisement is described in [D-Send]. |
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1.2.3. Local Redirect |
The Local Redirect MUST contain at least the following values:
IPv6 Header:
Destination the Source specified in the packet being
redirected.
Source the Primary Identifier of the router. |
Hop Limit 1
ICMP fields:
Code 4 for Local Redirect.
Sequence the last Sequence from the target node
Advertisement.
Lifetime the remaining Lifetime from the target node
Advertisement.
Extensions:
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU, the Maximum-Receive-Unit extension from the |
target node Advertisement.
Media-Access for interfaces which are not point-to-point
links, the Media-Access extension from the target
node Advertisement.
Other-Identifier for each IPv6 Unicast or Cluster Address |
associated with the target node. The Metric is |
always zero.
When the redirect applies to an entire cluster, |
the Prefix Size is set to the size of the cluster |
prefix. This enables the recipient node to |
determine the best next-hop without multiple |
redirects for each cluster.
Transit-Information
one or more, when the redirect is limited to a
specific Quality of Service. The Metric is |
always zero.
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Redirected-Header The target header.
In the unlikely event that not all extensions fit in a single
redirect, as constrained by the MTU of the link, the remaining
extensions are removed. Only a single redirect is sent.
The use of the Local Redirect is described in [D-Send]. |
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1.2.4. Remote Redirect
The Remote Redirect MUST contain at least the following values:
IPv6 Header:
Destination the Source specified in the packet being
redirected.
Source the Destination specified in the packet being |
redirected. |
Hop Limit from the Router Advertisement.
An Authentication Header is required.
ICMP fields:
Code 5 for Remote Redirect.
Sequence the last Sequence from the target node
Advertisement.
Lifetime the remaining Lifetime from the target node
Advertisement.
Extensions:
Change-Identifier for each of that interface's IPv6 Unicast or |
Cluster Addresses which is now reached via a |
Care-Of-Address.
Redirected-Header The target header.
In the unlikely event that not all extensions fit in a single
redirect, as constrained by the MTU of the link, the remaining
extensions are removed. Only a single redirect is sent.
The use of the Remote Redirect is described in [Mobility]. |
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1.3. Mobile Registration Request
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | LifeTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Identification +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Home Agent ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Care-Of-Address ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extensions ...
+-+-+-+-+-+-+-+-+-+-+-+-
IPv6 Header:
Destination The IPv6 Unicast Address of the Agent, when |
known.
Otherwise, the Mobile-Agents IPv6 Multicast |
Address (FF02::11). The scope is intra-link. |
Examination of the Care-Of-Address is used to
deliver the datagram to the correct Agent.
Source any IPv6 Unicast Address associated with the |
sending interface.
A Mobile Node MUST use the transient Care-Of-
Address when assigned; otherwise, the Home-
Address is used.
ICMP fields:
Type 35 |
Code Bitmask of optional capabilities:
1 - retain prior registrations
2 - registering through Foreign Agent
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LifeTime The seconds remaining before the registration is
considered expired. A value of zero indicates a
request for de-registration. A value of all ones
indicates infinity. *
Identification A sequence number assigned by the Mobile Node.
This is used to assist in matching Requests with
Replies.
A Network Time Protocol [RFC-1305] formatted
value is preferred. The low-order 32 bits of the
NTP format represent fractional seconds, and
those bits which are not available from a time
source SHOULD be generated from a good source of
randomness.
A battery-backed clock is the usual source of
this value. In more robust implementations,
Global Positioning System or authenticated NTP
values MAY be used. The elapsed time since
system startup or another such monotonically
increasing counter MAY be used, but is considered
less secure, as it could repeat each time the
machine is restarted, or when a poor source of
randomness is used for the low-order bits. See |
[Eastlake] for a discussion of sources of |
randomness.
It is possible to use an entirely random
"nonce" in this field, or to generate nonces
from previous registration exchanges. We have
not standardized this procedure because of
intellectual property concerns. It is also
incompatible with the expected venue of the
protocol, and presents difficulties with
interoperability and security validation.
The value MUST NOT be the same as an immediately
preceeding request, and SHOULD NOT repeat during
the lifetime of the Mobility Security Association
between the Mobile Node and the Home Agent. |
Home Agent The IPv6 Unicast Address of a Home Agent. |
Care-Of-Address The IPv6 Unicast Address for the decapsulation |
end of a tunnel.
Extensions:
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Other-Identifier the Home-Address of the Mobile Node. The Metric |
is always zero. |
When the request applies to an entire cluster, |
the Prefix Size is set to the size of the cluster |
prefix. |
Maximum-Receive-Unit |
for interfaces which do not have a fixed hardware |
MTU. |
Media-Access for interfaces which are not point-to-point |
links.
Mobile-Home Authentication
Immediately follows all non-authentication *
extensions.
When forwarded by a Foreign Agent, all extensions are copied without |
modification. Those extensions which are specific to the Foreign |
Agent are ignored by the Home Agent. |
The use of the Registration Request is described in [Mobility].
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1.4. Mobile Registration Reply
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | LifeTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Identification +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extensions ...
+-+-+-+-+-+-+-+-+-+-+-+-
IPv6 Header:
The Source and Destination of the Request message are swapped for
the Reply message.
Note that the Source of the original Mobile Registration Request
must be saved in order for a Foreign Agent to return the reply to
the correct Mobile Node.
ICMP fields:
Type 36 |
Code One of the following codes:
0 service will be provided.
denied by Foreign Agent,
16 reason unspecified.
17 administratively prohibited.
18 insufficient resources.
19 Mobile Node failed authentication.
20 Home Agent failed authentication.
21 Request LifeTime too long.
denied by Home Agent,
32 reason unspecified.
33 administratively prohibited.
34 insufficient resources.
35 Mobile Node failed authentication.
36 Foreign Agent failed authentication.
Up-to-date values of the Code field are specified |
in the most recent "Assigned Numbers" [RFC-1700].
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LifeTime The seconds remaining before the registration is
considered expired. A value of zero confirms a
request for de-registration. A value of all ones
indicates infinity. |
The value MAY be changed by the Home Agent.
Identification Copied from the Request message.
Extensions:
Other-Identifier the Home-Address of the Mobile Node. The Metric |
is always zero. |
When the reply applies to an entire cluster, the |
Prefix Size is set to the size of the cluster |
prefix.
Mobile-Home Authentication
Immediately follows all non-authentication *
extensions.
Note that the Care-Of-Address and Home Agent are
not present in the message. This provides a
separate calculation value for mutual
authentication.
When forwarded by a Foreign Agent, all extensions are copied without |
modification. Those extensions which are specific to the Foreign |
Agent are ignored by the Home Agent. |
The use of the Registration Reply is described in [Mobility].
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2. Extensions
Extensions allow variable amounts of information to be carried within
each Solicitation or Advertisement packet. Some extensions are
common to both packet types.
The end of the list of Extensions is indicated by the Payload Length
of the IPv6 packet.
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Extension | Length | Data ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Extension This document concerns the following values:
0 Single Pad (no length field)
1 Multiple Pads (with length field)
2 Change-Identifier |
3 Other-Identifier |
4 Node-Heard |
5 Routing-Information
6 Service-Information (reserved) |
7 Transit-Information
13 Hop-Limit |
14 Maximum-Receive-Unit
15 Media-Access
16 Mobility-Support |
17 Home-Address (obsolete)
32 Mobile-Home Authentication
64 Minimal Encapsulation (obsolete) |
65 GRE Encapsulation
254 Redirected-Header |
Up-to-date values are specified in the most recent |
"Assigned Numbers" [RFC-1700].
Length the length of the Data field. The Length does not |
include the Extension and Length octets. |
The Single Pad (extension 0) is a special case, |
which has neither Length field nor Data field.
Data zero or more octets. The format and length of the |
Data field is determined by the Extension and Length
fields.
When an extension is encountered which is not recognized, it is
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ignored. The Length field is used to skip the data field in |
searching for the next extension.
Every extension is aligned such that internal fields fall on natural
boundaries, except that fields larger than 64-bits need only be
aligned to 64-bit boundaries.
Any unused portion of the datagram between such Extensions is padded
as appropriate. The final Extension in a datagram does not require
trailing padding.
2.1. Single Pad
+-+-+-+-+-+-+-+-+
| Extension |
+-+-+-+-+-+-+-+-+
Extension 0
2.2. Multiple Pads
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
| Extension | Length | Data ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
Extension 1
Length the length of the Data field. |
Data zero or more bytes of zeroes. |
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2.3. Change-Identifier
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ *
| Extension | Length | 0 | Prefix Size | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | *
~ Identifier ~ |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 2
Length 34 |
Prefix Size the number of bits in the Identifier which define |
the cluster prefix width for the link. The value
ranges from 0 to 126. |
If the Identifier does not indicate a valid prefix, |
the value is zero. |
Non-routers MUST set this field to zero. |
Identifier an IPv6 Unicast or Cluster Address.
For Router Advertisements, gives advance indication that an address |
or prefix will no longer be routable. Applications SHOULD cease to |
accept new connections with the old value. Existing connections |
SHOULD issue a Remote Redirect.
For Remote Redirects, provides a Care-Of-Address to a Correspondent. |
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2.4. Other-Identifier
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | 0 | Prefix Size | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Metric | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Identifier ~ |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 3
Length 22 |
Prefix Size the number of bits in the Identifier which define |
the cluster prefix width for the link. The value
ranges from 0 to 126.
If the Identifier does not indicate a valid prefix, |
the value is zero.
Non-routers MUST set this field to zero.
Metric the preference level for use of this node to forward |
packets to the Identifier. Lower values indicate
greater preference.
Non-routers MUST set this field to zero. |
Identifier an IPv6 Unicast or Cluster Address.
For usage, see the specific message description. |
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2.5. Node-Heard |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | 0 | Prefix Size | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | Remaining LifeTime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Primary Identifier ~ |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MRU | 0 | Speed | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Quality |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Advertisement Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 4
Length 38 |
Prefix Size the number of bits in the Primary Identifier which |
define the cluster prefix width for the link. The
value ranges from 0 to 126.
If the Primary Identifier does not indicate a valid |
prefix, the value is zero.
Sequence Number the last heard sequence number from the node. |
Remaining LifeTime
the seconds remaining before the entry is considered |
expired. |
Primary Identifier |
the primary IPv6 Unicast or Cluster Address for the |
node, taken from the Source field of the
Advertisement heard.
MRU the maximum size packet that the node will receive |
over the link.
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Speed the speed of the link over which the advertisement |
or solicitation was heard. Higher values indicate
greater speed. The speed value is related to int(
10 * ln( speed / 100 ) ) in bits per second.
0 link is down
1 - 9 reserved
10 300 or less
24 1,200 96 1,544,000 T1
31 2,400 99 2,048,000 E1
38 4,800 106 4,000,000 Token Ring
42 7,200 110 6,312,000 T2
45 9,600 115 10,000,000 Ethernet
49 14,400 119 16,000,000 Token Ring
52 19,200
56 28,800 130 44,736,000 T3
59 38,400 142 155,520,000 STS-3,STM-1
63 57,600 202 622,080,000 STS-12,STM-4
64 64,000 216 2,488,320,000 STS-48,STM-16
71 128,000
73 153,600
78 256,000
Quality an indication of the signal quality received from |
this node. Higher values indicate greater quality.
Advertisement Count
the number of advertisements that have been heard |
from the identified node.
Error Count the number of errors which have been detected on the |
link with the identified node.
This extension is included in an Advertisement message to indicate a |
node which has been heard.
The MRU, Speed, Quality, Advertisement Count, and Error Count are
primarily used for selecting among multiple paths in a wireless
environment.
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2.6. Routing-Information
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | Preference |C| Prefix Size | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | *
~ Identifier ~ |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 5
Length 18 |
Preference the preference level for use of this node to forward |
packets having a Source longest match with the |
Identifier. Higher values indicate greater |
preference.
C Cluster bit. When this bit is set to 1, the IPv6
Cluster is entirely confined to the link. When
forwarding, a node MAY use the prefix to determine
whether a target node is on the link. *
Prefix Size the number of bits in the Identifier which define |
the cluster prefix width for the link. The value
ranges from 0 to 126.
If the Identifier does not indicate a valid prefix, |
the value is zero. |
Identifier one of the IPv6 Unicast or Cluster Addresses for |
this interface.
This extension is found in Router Advertisements. |
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2.7. Transit-Information |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | 0 | QoS | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Metric |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 7
Length 6
QoS a quality of service for which transit will be |
accepted.
Metric the preference level for use of this link to forward |
packets of the indicated Quality of Service. Lower
values indicate greater preference.
For redirects, this indicates that the redirect is limited to only |
the particular service. If this extension is not included, the
redirect includes all services.
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2.8. Hop-Limit |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Extension | Length | Hops | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
Extension 13 |
Length 1 |
Hops the currently recommended IPv6 Hop Limit. |
Up-to-date values are specified in the most recent |
"Assigned Numbers" [RFC-1700].
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2.9. Maximum-Receive-Unit
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | MRU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 14
Length 2
MRU the maximum size packet that the node will receive |
over the link.
This extension MUST be included in those messages sent from an |
interface for which there is no dependable MTU, such as Frame-Relay
or Asynchronous Transfer Mode.
It MUST NOT be included in messages such as the Remote Redirect which
pass through intermediate nodes.
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2.10. Media-Access
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length | Family | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Media Address ... |
+-+-+-+-+-+-+-+-+-+-+-+-
Extension 15
Length >= 2 |
Family the Address Family Number. |
Up-to-date values are specified in the most recent |
"Assigned Numbers" [RFC-1700].
Media Address the media address which is used to access this node. |
This field is variable in length.
The Media Address is always specified in Canonical
order.
This extension MUST be included in those messages sent from an |
interface on a multi-access media.
It MUST NOT be included in a message sent from a point-to-point
interface, or in messages such as the Remote Redirect which pass
through intermediate nodes.
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2.11. Mobility-Support |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length |F| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 16 |
Length >= 1 |
F Foreign Agent bit. When this bit is set to 1, |
Mobile Registration through the Foreign Agent is |
required, even when the Mobile Node has acquired a |
transient Care-Of-Address. |
Reserved Sent as zero; ignored on reception. |
This extension is found in Router Advertisements. |
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2.12. Mobile-Home Authentication Extension
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| Extension | Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Authenticator ... |
+-+-+-+-+-+-+-+-+-+-+-+- |
Extension 32
Length The number of data bytes in the Extension (16 when
MD5 is used).
Authenticator variable length (128 bits for MD5), 64-bit aligned. |
A hash value taken over a stream of bytes consisting
of the shared secret, followed by (concatenated
with) the fields in the Mobile Registration message
beginning with the Type field, including all prior
extensions, and the Type and Length of this
extension, but not including the Authenticator field
itself.
This extension is found in all Mobile Registration Requests and |
Replies.
The value differs depending on the direction the message is sent,
since the Mobile Registration Request and Reply have different
fields.
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2.13. GRE Encapsulation Extension |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Extension 65 |
Length 0 |
This extension is found in Router Advertisements and Mobile |
Registration Requests. GRE is described in [RFC-1701]. |
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2.14. Redirected-Header |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 Header(s) ...
+-+-+-+-+-+-+-+-+-+-+-+-
Extension 254 |
Length >= 64 |
IPv6 Header(s) variable length, 64-bit aligned. |
This extension is included in the Local or Remote Redirect to verify |
the traffic that is being redirected. |
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Security Considerations
Whenever Ran gets them done. |
References
[D-Send] |
[Eastlake] |
[IPv6-Address]
[IPv6-ICMP] |
[Mobility]
[RFC-1305] |
[RFC-1700] |
[RFC-1701]
Acknowledgements
Many thanks to Fred Goldstein, K1IO (DEC, BBN) for his pioneering |
work on Radio Shortest Path First (RSPF) for Amateur Packet Radio. |
Thanks also for suggestions and contributions from the Simple-IP |
Working Group and the Mobile-IP Working Group. |
Special thanks for implementation review by Alex Conta (DEC), Dan |
McDonald (Naval Research Laboratory), and Fred Rabouw (Network |
Systems Netherlands).
Author's Address
Questions about this memo can also be directed to:
William Allen Simpson
Daydreamer
Computer Systems Consulting Services
1384 Fontaine
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Madison Heights, Michigan 48071
Bill.Simpson@um.cc.umich.edu
bsimpson@MorningStar.com
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