Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6)
draft-ietf-ipngwg-icmp-02
The information below is for an old version of the document that is already published as an RFC.
| Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 1885.
|
|
|---|---|---|---|
| Author | Alex Conta | ||
| Last updated | 2013-03-02 (Latest revision 1995-06-09) | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | (None) | |
| Document shepherd | (None) | ||
| IESG | IESG state | Became RFC 1885 (Proposed Standard) | |
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| Send notices to | (None) |
draft-ietf-ipngwg-icmp-02
Network Working Group A. Conta (Digital Equipment Corporation)
INTERNET-DRAFT S. Deering (Xerox PARC)
June 1995
Internet Control Message Protocol (ICMPv6)
for the Internet Protocol Version 6 (IPv6)
Specification
<draft-ietf-ipngwg-icmp-02.txt>
Status of this Memo
This document is an Internet Draft. Internet Drafts are working
documents of the Internet Engineering Task Force (IETF), its Areas,
and its Working Groups. Note that other groups may also distribute
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Distribution of this memo is unlimited.
Abstract
This document specifies a set of Internet Control Message Protocol
(ICMP) messages for use with version 6 of the Internet Protocol
(IPv6). The Internet Group Management Protocol (IGMP) messages
specified in RFC-1112 have been merged into ICMP, for IPv6, and are
included in this document.
Table of Contents
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1. Introduction........................................3
2. ICMPv6 (ICMP for IPv6)..............................3
2.1 Message General Format.......................3
2.2 Message Source Address Determination.........5
2.3 Message Checksum Calculation.................5
2.4 Message Processing Rules.....................8
3. ICMPv6 Error Messages..............................10
3.1 Destination Unreachable Message.............10
3.2 Packet Too Big Message......................12
3.3 Time Exceeded Message.......................13
3.4 Parameter Problem Message...................14
4. ICMPv6 Informational Messages......................16
4.1 Echo Request Message........................16
4.2 Echo Reply Message..........................17
4.3 Group Membership Messages...................18
5. References.........................................19
6. Acknowledgements...................................20
7. Security Considerations............................20
Authors' Addresses....................................21
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1. Introduction
The Internet Protocol, version 6 (IPv6) is a new version of IP. IPv6
uses the Internet Control Message Protocol (ICMP) as defined for IPv4
[RFC-792], with a number of changes. The Internet Group Membership
Protocol (IGMP) specified for IPv4 [RFC-1112] has also been revised
and has been absorbed into ICMP for IPv6. The resulting protocol is
called ICMPv6, and has an IPv6 Next Header value 58.
This document describes the format of a set of control messages used
in ICMPv6. It does not describe the procedures for using these
messages to achieve functions like Path MTU discovery or multicast
group membership maintenance; such procedures are described in other
documents (e.g., [RFC-1112, RFC-1191]). Other documents may also
introduce additional ICMPv6 message types, such as Neighbor Discovery
messages [IPv6-DISC], subject to the general rules for ICMPv6
messages given in section 2 of this document.
Terminology defined in the IPv6 specification [IPv6] and the IPv6
Routing and Addressing specification [IPv6-ADDR] applies to this
document as well.
2. ICMPv6 (ICMP for IPv6)
ICMPv6 is used by IPv6 nodes to report errors encountered in
processing packets, and to perform other internet-layer functions,
such as diagnostics (ICMPv6 "ping") and multicast membership
reporting. ICMPv6 is an integral part of IPv6 and MUST be fully
implemented by every IPv6 node.
2.1 Message General Format
ICMPv6 messages are grouped into two classes: error messages and
informational messages. Error messages are identified as such by
having a zero in the high-order bit of their message Type field
values. Thus, error messages have message Types from 0 to 127;
informational messages have message Types from 128 to 255.
This document defines the message formats for the following ICMPv6
messages:
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ICMPv6 error messages:
1 Destination Unreachable (see section 3.1)
2 Packet Too Big (see section 3.2)
3 Time Exceeded (see section 3.3)
4 Parameter Problem (see section 3.4)
ICMPv6 informational messages:
128 Echo Request (see section 4.1)
129 Echo Reply (see section 4.2)
130 Group Membership Query (see section 4.3)
131 Group Membership Report (see section 4.3)
132 Group Membership Termination (see section 4.3)
Every ICMPv6 message is preceded by an IPv6 header and zero or more
IPv6 extension headers. The ICMPv6 header is identified by a Next
Header value of 58 in the immediately preceding header. (NOTE: this
is different than the value used to identify ICMP for IPv4.)
The ICMPv6 messages have the following general 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Message Body +
| |
The type field indicates the type of the message. Its value
determines the format of the remaining data.
The code field depends on the message type. It is used to create an
additional level of message granularity.
The checksum is the 16-bit one's complement of the one's complement
sum of the IPv6 Source Address, the IPv6 Destination Address the IPv6
Payload Length, the Next Header type that identifies ICMPv6 (value =
58), and the entire ICMPv6 message starting with the ICMPv6 message
type.
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2.2 Message Source Address Determination
A node that sends an ICMPv6 message has to determine both the Source
and Destination IPv6 Addresses in the IPv6 header before calculating
the checksum. If the node has more than one unicast address, it must
choose the Source Address of the message as follows:
(a) If the message is a response to a message sent to one of the
node's unicast addresses, the Source Address of the reply must be
that same address.
(b) If the message is a response to a message sent to a multicast or
anycast group in which the node is a member, the Source Address
of the reply must be a unicast address belonging to the interface
on which the multicast packet was received.
(c) If the message is a response to a message sent to an address that
does not belong to the node, the Source Address should be that
unicast address belonging to the node that will be most helpful
in diagnosing the error. For example, if the message is a
response to a packet forwarding action that cannot complete
successfully, the Source Address should be a unicast address
belonging to the interface on which the packet forwarding failed.
(d) Otherwise, the node's routing table must be examined to determine
which interface will be used to transmit the message to its
destination, and a unicast address belonging to that interface
must be used as the Source Address of the message.
2.3 Message Checksum Calculation
An illustration of the IPv6 and ICMPv6 header fields fetched into a
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pseudo-header for calculating the ICMPv6 checksum is:
From the IPv6 Header:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | Next Hdr = 58 | Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
From the ICMPv6 Header and Message:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum = zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Message Body +
| |
An illustration of the IPv6, IPv6 Hop-by-Hop Jumbo Payload Option and
ICMPv6 headers fields fetched into a pseudo-header for calculating
the ICMPv6 checksum in case of a Jumbo Payload (IPv6 packet payload
longer than 65535 octets) is:
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From the IPv6 Header:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Source Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Destination Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| zero | Next Hdr = 58 | zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
From the IPv6 Hop-by-Hop Jumbo Payload Option Extension Header:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
From the ICMPv6 Header and Message:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum = zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Message Body +
| |
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The ICMPv6 checksum calculation rules are:
(a) If the packet contains a Routing header, the Destination Address
used in the pseudo-header is that of the final destination. At
the originating system, 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 IPv6 header.
(b) The Next Header value in the pseudo-header identifies the ICMPv6
protocol (e.g., 58). It will differ from the Next Header value in
the IPv6 header if there are additional headers between the IPv6
header and the ICMPv6 header.
(c) The Payload Length used in the pseudo-header is the length of the
ICMPv6 message, including the ICMPv6 header. It will be less
than the Payload Length in the IPv6 header or in the IPv6 Hop-
by-Hop Jumbo Payload Option header if there are additional
headers between the IPv6 header and the ICMPv6 header,
respectively the IPv6 Hop-by-Hop Jumbo Option Header and the
ICMPv6 Header.
(d) For computing the checksum, the checksum field is set to zero.
(NOTE: the inclusion of the IPv6 header fields in the ICMPv6
checksum is a change from IPv4; see [IPv6] for the rationale for
this change.)
2.4 Message Processing Rules
Implementations MUST observe the following rules when processing
ICMPv6 messages (from [RFC-1122]):
(a) If an ICMPv6 error message of unknown type is received, it MUST
be passed to the upper layer.
(b) If an ICMPv6 informational message of unknown type is received,
it MUST be silently discarded.
(c) Every ICMPv6 error message (type < 128) includes as much of the
IPv6 offending (invoking) packet (the packet that causes the
error) as will fit without making the error message packet exceed
576 octets.
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(d) In those cases where the Internet layer is required to pass a
ICMPv6 error message to the transport layer, the IPv6 Transport
Protocol is extracted from the original header (contained in the
body of the ICMPv6 error message) and used to select the
appropriate transport protocol entity to handle the error.
(e) An ICMPv6 error message MUST NOT be sent as a result of
receiving:
(e.1) an ICMPv6 error message, or
(e.2) a packet destined to an IPv6 multicast address (an
exception to this rule is the Packet Too Big Message -
Section 3.2 - to allow Path MTU discovery to work for IPv6
multicast), or
(e.3) a packet sent as a link-layer multicast, (the exception
from e.2. applies to this case too), or
(e.4) a packet sent as a link-layer broadcast, (the exception
from e.2., applies to this case too), or
(e.5) a packet whose source address does not uniquely identify a
single node -- e.g., the IPv6 Unspecified Address, or an
IPv6 multicast address, or an IPv6 anycast address.
(f) Finally, to each sender of an erroneous data packet, an IPv6 node
MUST limit the rate of ICMPv6 error messages sent, in order to
limit the bandwidth and forwarding costs incurred by the error
messages when a generator of erroneous packets does not respond
to those error messages by ceasing its transmissions. There are
a variety of ways of implementing the rate-limiting function, for
example:
(f.1) Timer-based - for example, limiting the rate of
transmission of error messages to a given source, or to
any source, to at most once every T milliseconds.
(f.2) Bandwidth-based - for example, limiting the rate at which
error messages are sent from a particular interface to
some fraction F of the attached link's bandwidth.
The limit parameters (e.g., T or F in the above examples) MUST be
configurable for the node, with a conservative default value
(e.g., T = 1 second, NOT 0 seconds, or F = 2 percent, NOT 100
percent).
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The following sections describe the message formats for the above
ICMPv6 messages.
3. ICMPv6 Error Messages
3.1 Destination Unreachable Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Unused |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| As much of invoking packet |
+ as will fit without ICMPv6 packet +
| exceeding 576 octets |
+ +
| |
IPv6 Fields:
Destination Address
Copied from the Source Address field of the invoking
packet.
ICMPv6 Fields:
Type 1
Code 0 - no route to destination
1 - communication with destination
administratively prohibited
2 - not a neighbor
3 - address unreachable
4 - port unreachable
Unused This field is unused for all code values.
It must be initialized to zero by the sender
and ignored by the receiver.
Description
A Destination Unreachable message SHOULD be generated by a router, or
by the IPv6 layer in the originating node, in response to a packet
that cannot be delivered to its destination address for reasons other
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than congestion. (An ICMPv6 message MUST NOT be generated if a
packet is dropped due to congestion.)
If the reason for the failure to deliver is lack of a matching entry
in the forwarding node's routing table, the Code field is set to 0
(NOTE: this error can occur only in routers that do not hold a
"default route" in their routing tables).
If the reason for the failure to deliver is administrative
prohibition, e.g., a "firewall filter", the Code field is set to 1.
If the reason for the failure to deliver is that the next destination
address in the Routing header is not a neighbor of the processing
node but the "strict" bit is set for that address, then the Code
field is set to 2.
If there is any other reason for the failure to deliver, e.g.,
inability to resolve the IPv6 destination address into a
corresponding link address, or a link-specific problem of some sort,
then the Code field is set to 3.
A destination node SHOULD send a Destination Unreachable message with
Code 4 in response to a packet for which the transport protocol
(e.g., UDP) has no listener, if that transport protocol has no
alternative means to inform the sender.
Upper layer notification
A node receiving the ICMPv6 Destination Unreachable message MUST
notify the upper layer.
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3.2 Packet Too Big Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| As much of invoking packet |
+ as will fit without ICMPv6 packet +
| exceeding 576 octets |
+ +
| |
IPv6 Fields:
Destination Address
Copied from the Source Address field of the invoking
packet.
ICMPv6 Fields:
Type 2
Code 0
MTU The Maximum Transmission Unit of the next-hop link.
Description
A Packet Too Big MUST be sent by a router in response to a packet
that it cannot forward because the packet is larger than the MTU of
the outgoing link. The information in this message is used as part
of the Path MTU Discovery process [RFC-1191].
Sending a Packet Too Big Message makes an exception to one of the
rules of when to send an ICMPv6 error message, in that unlike other
messages, it is sent in response to a packet received with an IPv6
multicast destination address, or a link-layer multicast or link-
layer broadcast address.
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Upper layer notification
An incoming Packet Too Big message MUST be passed to the upper layer.
3.3 Time Exceeded Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Unused |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| As much of invoking packet |
+ as will fit without ICMPv6 packet +
| exceeding 576 octets |
+ +
| |
IPv6 Fields:
Destination Address
Copied from the Source Address field of the invoking
packet.
ICMPv6 Fields:
Type 3
Code 0 - hop limit exceeded in transit
1 - fragment reassembly time exceeded
Unused This field is unused for all code values.
It must be initialized to zero by the sender
and ignored by the receiver.
Description
If a router receives a packet with a Hop Limit of zero, or a router
decrements a packet's Hop Limit to zero, it MUST discard the packet
and send an ICMPv6 Time Exceeded message with Code 0 to the source of
the packet. This indicates either a routing loop or too small an
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initial Hop Limit value.
The router sending an ICMPv6 Time Exceeded message with Code 0 SHOULD
consider the receiving interface of the packet as the interface on
which the packet forwarding failed in following rule (d) for
selecting the Source Address of the message.
IPv6 systems are expected to avoid fragmentation by implementing Path
MTU discovery. However, IPv6 defines an end-to-end fragmentation
function for backwards compatibility with existing higher-layer
protocols. All IPv6 implementations are required to support
reassembly of IPv6 fragments. There MUST be a reassembly timeout.
The reassembly timeout SHOULD be a fixed value. It is recommended
that this value lie between 60 and 120 seconds. If the timeout
expires, the partially-reassembled packet MUST be discarded. If the
fragment with offset zero was received during the reassembly time,
the destination host SHOULD also send an ICMPv6 Time Exceeded message
with Code 1 to the source of the fragment.
Upper layer notification
An incoming Time Exceeded message MUST be passed to the upper layer.
3.4 Parameter Problem Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pointer |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| As much of invoking packet |
+ as will fit without ICMPv6 packet +
| exceeding 576 octets |
+ +
| |
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IPv6 Fields:
Destination Address
Copied from the Source Address field of the invoking
packet.
ICMPv6 Fields:
Type 4
Code 0 - erroneous header field encountered
1 - unrecognized Next Header type encountered
2 - unrecognized IPv6 option encountered
Pointer identifies the octet offset within the
invoking packet where the error was detected.
The pointer will point beyond the end of the ICMPv6
packet if the field in error is beyond what can fit
in the 576-byte limit of an ICMPv6 error message.
Description
If an IPv6 node processing a packet finds a problem with a field in
the IPv6 header or extension headers such that it cannot complete
processing the packet, it MUST discard the packet and SHOULD send an
ICMPv6 Parameter Problem message to the packet's source, indicating
the type and location of the problem.
The pointer identifies the octet of the original datagram's header
where the error was detected. For example, an ICMPv6 message with
Type field = 4, Code field = 1, and Pointer field = 48 would indicate
that the IPv6 extension header following the IPv6 header of the
original datagram is holds an unrecognized Next Header field value.
Upper layer notification
A node receiving this ICMPv6 message MUST notify the upper layer.
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4. ICMPv6 Informational Messages
4.1 Echo Request Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-
IPv6 Fields:
Destination Address
Any legal IPv6 address.
ICMPv6 Fields:
Type 128
Code 0
Identifier If code = 0, an identifier to aid in matching
Echo Replies to this Echo Request. May be zero.
Sequence Number
If code = 0, a sequence number to aid in matching
Echo Replies to this Echo Request. May be zero.
Data If code = 0, zero or more octets of arbitrary data.
Description
Every node MUST implement an ICMPv6 Echo responder function that
receives Echo Requests and sends corresponding Echo Replies. A node
SHOULD also implement an application-layer interface for sending Echo
Requests and receiving Echo Replies, for diagnostic purposes.
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Upper layer notification
A node receiving this ICMPv6 message MAY notify the upper layer.
4.2 Echo Reply Message
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data ...
+-+-+-+-+-
IPv6 Fields:
Destination Address
Copied from the Source Address field of the invoking
Echo Request packet.
ICMPv6 Fields:
Type 129
Code 0
Identifier If code = 0, the identifier from the invoking
Echo Request message.
Sequence If code = 0, the sequence number from the invoking
Number Echo Request message.
Data If code = 0, the data from the invoking
Echo Request message
Description
Every node MUST implement an ICMPv6 Echo responder function that
receives Echo Requests and sends corresponding Echo Replies. A node
SHOULD also implement an application-layer interface for sending Echo
Requests and receiving Echo Replies, for diagnostic purposes.
The source address of an Echo Reply sent in response to a unicast
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Echo Request message MUST be the same as the destination address of
that Echo Request message.
An Echo Reply SHOULD be sent in response to an Echo Request message
sent to an IPv6 multicast address. The source address of the reply
MUST be a unicast address belonging to the interface on which the
multicast Echo Request message was received.
The data received in the ICMPv6 Echo Request message MUST be returned
entirely and unmodified in the ICMPv6 Echo Reply message, unless the
Echo Reply would exceed the MTU of the path back to the Echo
requester, in which case the data is truncated to fit that path MTU.
Upper layer notification
Echo Reply messages MUST be passed to the ICMPv6 user interface,
unless the corresponding Echo Request originated in the IP layer.
4.3 Group Membership Messages
The ICMPv6 Group Membership Messages have 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Response Delay | Unused |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| Multicast |
+ +
| Address |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
IPv6 Fields:
Destination Address
In a Group Membership Query message, the multicast
address of the group being queried, or the Link-Local
All-Nodes multicast address.
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In a Group Membership Report or a Group Membership
Termination message, the multicast address of the
group being reported or terminated.
Hop Limit 1
ICMPv6 Fields:
Type 130 - Group Membership Query
131 - Group Membership Report
132 - Group Membership Termination
Code 0
Maximum Response Delay
In Query messages, the maximum time that responding
Report messages may be delayed, in milliseconds.
In Report and Termination messages, this field is
is initialized to zero by the sender and ignored by
receivers.
Unused Initialized to zero by the sender; ignored by receivers.
Multicast Address
The address of the multicast group about which the
message is being sent. In Query messages, the Multicast
Address field may be zero, implying a query for all
groups.
Description
The ICMPv6 Group Membership messages are used to convey information
about multicast group membership from nodes to their neighboring
routers. The details of their usage is given in [RFC-1112].
5. References
[IPv6]S. Deering, R. Hinden, "Internet Protocol, Version 6,
Specification", April 1995
[IPv6-ADDR]
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R. Hinden, "IP Version 6 Addressing Architecture", April 1995
[IPv6-DISC]
W. A. Simpson, "IPv6 Neighbor Discovery", April 1995
[RFC-792]
J. Postel, "Internet Control Message Protocol", RFC 792.
[RFC-1112]
S. Deering, "Host Extensions for IP Multicasting", RFC 1112.
[RFC-1122]
R. Braden, "Requirements for Internet Hosts - Communication
Layers", RFC 1122.
[RFC-1191]
J. Mogul and S. Deering, "Path MTU Discovery", RFC 1191.
6. Acknowledgements
The document is derived from previous ICMP drafts of the SIPP and
IPng working group.
The IPng working group and particularly Robert Elz, Jim Bound, Bill
Simpson, Thomas Narten, Charlie Lynn, Bill Fink, and Scott Bradner
(in chronological order) provided extensive review information and
feedback.
7. Security Considerations
Security considerations are not discussed in this memo.
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Authors' Addresses:
Alex Conta Stephen Deering
Digital Equipment Corporation Xerox Palo Alto Research Center
110 Spitbrook Rd 3333 Coyote Hill Road
Nashua, NH 03062 Palo Alto, CA 94304
+1-603-881-0744 +1-415-812-4839
email: conta@zk3.dec.com email: deering@parc.xerox.com