Extending ICMP for Node Identification
draft-fenner-intarea-extended-icmp-hostid-01
| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Bill Fenner (ˢˣˠ) , Reji Thomas | ||
| Last updated | 2024-04-23 | ||
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| Intended RFC status | (None) | ||
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| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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draft-fenner-intarea-extended-icmp-hostid-01
Internet Area Working Group B. Fenner
Internet-Draft R. Thomas
Intended status: Standards Track Arista Networks
Expires: 25 October 2024 23 April 2024
Extending ICMP for Node Identification
draft-fenner-intarea-extended-icmp-hostid-01
Abstract
RFC5837 describes a mechanism for Extending ICMP for Interface and
Next-Hop Identification, which allows providing additional
information in an ICMP error that helps identify interfaces
participating in the path. This is especially useful in environments
where each interface may not have a unique IP address to respond to,
e.g., a traceroute.
This document introduces a similar ICMP extension for Node
Identification. It allows providing a unique IP address and/or a
textual name for the node, in the case where each node may not have a
unique IP address (e.g., the IPv6 nexthop deployment case described
in draft-chroboczek-intarea-v4-via-v6).
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at
https://fenner.github.io/icmp-node-id/draft-fenner-intarea-extended-
icmp-hostid.html. Status information for this document may be found
at https://datatracker.ietf.org/doc/draft-fenner-intarea-extended-
icmp-hostid/.
Discussion of this document takes place on the Internet Area Working
Group Working Group mailing list (mailto:int-area@ietf.org), which is
archived at https://mailarchive.ietf.org/arch/browse/int-area/.
Subscribe at https://www.ietf.org/mailman/listinfo/int-area/.
Source for this draft and an issue tracker can be found at
https://github.com/fenner/icmp-node-id.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Node Identification Object . . . . . . . . . . . . . . . . . 3
3.1. C-Type Meaning in a Node Identification Object . . . . . 4
3.2. Node IP Address Sub-Object . . . . . . . . . . . . . . . 5
3.3. Node Name Sub-Object . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. Normative References . . . . . . . . . . . . . . . . . . 7
6.2. Informative References . . . . . . . . . . . . . . . . . 8
Appendix A. Change history . . . . . . . . . . . . . . . . . . . 8
A.1. Changes since
draft-fenner-intarea-extended-icmp-hostid-00 . . . . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
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1. Introduction
In addition to adding incoming interface information to a traceroute
using the mechanisms described in [RFC5837], a network operator may
be interested in adding information to identify nodes themselves.
[I-D.chroboczek-intarea-v4-via-v6] describes a scenario in which
individual nodes do not have unique IPv4 addresses to use to reply to
an IPv4 traceroute, so additional information is needed.
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Node Identification Object
This section defines the Node Identification Object, an ICMP
Extension Object with a Class-Num (Object Class Value) of 5 that can
be appended to the following messages:
* ICMPv4 Time Exceeded
* ICMPv4 Destination Unreachable
* ICMPv4 Parameter Problem
* ICMPv6 Time Exceeded
* ICMPv6 Destination Unreachable
For reasons described in [RFC4884], this extension cannot be appended
to any of the currently defined ICMPv4 or ICMPv6 messages other than
those listed above.
The extension defined herein MAY be appended to any of the above
listed messages and SHOULD be appended whenever required to identify
the node and when local policy or security considerations do not
supersede this requirement.
Similarly to the Interface Identification Object defined in
[RFC5837], there are two different pieces of information that can
appear in a Node Information Object.
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1. An IP Address Sub-Object MAY be included, containing an address
of sufficient scope to identify the node within the domain. The
IP Address Sub-Object is defined in Section 3.2 of this memo.
2. A Node Name Sub-Object MAY be included, as specified in
Section 3.3, containing up to 63 octets of the yang sys:hostname
or another appropriate name uniquely identifying the node.
3.1. C-Type Meaning in a Node Identification Object
The C-Type contains a bitmask describing what information is included
in this Node Identification Object.
Bit 0 1 2 3 4 5 6 7
+-------+-------+-------+-------+-------+-------+-------+-------+
| Reserved | IPAddr| name | Rsvd2 |
+-------+-------+-------+-------+-------+-------+-------+-------+
Figure 1: C-Type for the Node Identification Object
The following are bit-field definitions for C-Type:
Reserved (bits 0-4): These bits are reserved for future use and MUST
be set to 0 on transmit and ignored on receipt.
IP Addr (bit 5) : When set, an IP Address Sub-Object is present.
When clear, an IP Address Sub-Object is not present. The IP Address
Sub-Object is described in Section 3.2 of this memo.
Node Name (bit 6): When set, an Node Name Sub-Object is included.
When clear, it is not included. The Name Sub-Object is described in
Section 3.3 of this memo.
Rsvd2 (bit 7): This bit is reserved for future use and MUST be set to
0 on transmit and ignored on receipt.
The information included does not self-identify, so this
specification defines a specific ordering for sending the information
that must be followed.
If bit 5 (IP Address) is set, a Node IP Address Sub-Object MUST be
sent first. If bit 6 (Name) is set, a Node Name Sub-Object MUST be
sent next. The information order is thus: IP Address Sub-Object,
Node Name Sub-Object. Any or all pieces of information may be
present or absent, as indicated by the C-Type. Any data that follows
these optional pieces of information MUST be ignored.
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It is valid (though pointless until additional bits are assigned by
IANA) to receive an Interface Information Object where bits 5 and 6
are both 0; this MUST NOT generate a warning or error.
3.2. Node IP Address Sub-Object
If the Node Identification Object identifies the node by address, the
Object Payload contains an address sufficient to identify the node
within the appropriate scope - global or as otherwise configured - as
depicted in Figure 2.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AFI | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Address...
Figure 2: Node Identification Object - C-Type 2 Payload
Payload fields are defined as follows:
* Address Family Identifier (AFI): This 16-bit field identifies the
type of address represented by the Address field. Values for this
field represent a subset of values found in the IANA registry of
Address Family Numbers (available from
[IANA.address-family-numbers]). Valid values are 1 (representing
a 32-bit IPv4 address) and 2 (representing a 128-bit IPv6
address).
* Reserved: This field MUST be set to 0 and ignored upon receipt.
* Address: This variable-length field represents an address of
appropriate scope (global, if none other defined) that can be used
to identify the node.
3.3. Node Name Sub-Object
Figure 3 depicts the Node Name Sub-Object:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Node Name...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Node Identification Object Node Name Sub-Object
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The Node Name Sub-Object MUST have a length that is a multiple of 4
octets and MUST NOT exceed 64 octets.
The Length field represents the length of the Node Name Sub- Object,
including the length and the interface name in octets. The maximum
valid length is 64 octets. The length is constrained to ensure there
is space for the start of the original packet and additional
information.
The second field contains the human-readable node name. The node
name SHOULD be the sys:hostname [RFC7317], if less than 64 octets, or
the first 63 octets of the sys:hostname, if the sys:hostname is
longer. The node name MAY be some other human-meaningful name of the
interface. The node name MUST be padded with ASCII NUL characters if
the object would not otherwise terminate on a 4-octet boundary.
The interface name MUST be represented in the UTF-8 charset [RFC3629]
using the Default Language [RFC2277].
4. Security Considerations
It may not be desirable to allow this information to be sent to an
arbitrary receiver. The addition of this information SHOULD be
configurable, and MUST default to off. An implementation SHOULD
determine what objects may be appended to a given message based on
the destination IP address of the ICMP message that will contain the
objects.
The intended field of use for the extensions defined in this document
is administrative debugging and troubleshooting. The extensions
herein defined supply additional information in ICMP responses.
These mechanisms are not intended to be used in non-debugging
applications.
This document does not specify an authentication mechanism for the
extension that it defines. Application developers should be aware
that ICMP messages and their contents are easily spoofed.
5. IANA Considerations
This IANA has allocated the ICMP Extension Object Class value 5 to
the extension described above. The corresponding Class Sub-types
Registry is as follows:
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+================+===========================+===========+
| C-Type (Value) | Description | Reference |
+================+===========================+===========+
| 0-4 | Unallocated - allocatable | [This |
| | with Standards Action | document] |
+----------------+---------------------------+-----------+
| 5 | IP Address Sub-object | [This |
| | included | document] |
+----------------+---------------------------+-----------+
| 6 | Name Sub-object included | [This |
| | | document] |
+----------------+---------------------------+-----------+
| 7 | Unallocated - allocatable | [This |
| | with Standards Action | document] |
+----------------+---------------------------+-----------+
Table 1
6. References
6.1. Normative References
[IANA.address-family-numbers]
IANA, "Address Family Numbers",
<http://www.iana.org/assignments/address-family-numbers>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC2277] Alvestrand, H., "IETF Policy on Character Sets and
Languages", BCP 18, RFC 2277, DOI 10.17487/RFC2277,
January 1998, <https://www.rfc-editor.org/rfc/rfc2277>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <https://www.rfc-editor.org/rfc/rfc3629>.
[RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro,
"Extended ICMP to Support Multi-Part Messages", RFC 4884,
DOI 10.17487/RFC4884, April 2007,
<https://www.rfc-editor.org/rfc/rfc4884>.
[RFC5837] Atlas, A., Ed., Bonica, R., Ed., Pignataro, C., Ed., Shen,
N., and JR. Rivers, "Extending ICMP for Interface and
Next-Hop Identification", RFC 5837, DOI 10.17487/RFC5837,
April 2010, <https://www.rfc-editor.org/rfc/rfc5837>.
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[RFC7317] Bierman, A. and M. Bjorklund, "A YANG Data Model for
System Management", RFC 7317, DOI 10.17487/RFC7317, August
2014, <https://www.rfc-editor.org/rfc/rfc7317>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
6.2. Informative References
[I-D.chroboczek-intarea-v4-via-v6]
Chroboczek, J., Kumari, W. A., and T. Høiland-Jørgensen,
"IPv4 routes with an IPv6 next hop", Work in Progress,
Internet-Draft, draft-chroboczek-intarea-v4-via-v6-00, 21
January 2024, <https://datatracker.ietf.org/doc/html/
draft-chroboczek-intarea-v4-via-v6-00>.
Appendix A. Change history
This section is to be removed before publishing as an RFC.
A.1. Changes since draft-fenner-intarea-extended-icmp-hostid-00
* Instead of having two different messages with the same Class Value
and different CType values, we copy the bitmap implementation from
[RFC5837]. The re-use of bit positions means that packet parsing
and generation code can be largely reused from existing [RFC5837]
code.
Acknowledgments
This document derives text heavily from [RFC5837], since the
underlying mechanism is identical, and only the semantics of the
message differs. Thanks are therefore due to that document's
authors: Alia K. Atlas, Ronald P. Bonica, Carlos Pignataro, Naiming
Shen and JR. Rivers.
Authors' Addresses
Bill Fenner
Arista Networks
5453 Great America Parkway
Santa Clara, California 95054
United States of America
Email: fenner@fenron.com
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Reji Thomas
Arista Networks
Global Tech Park
Bangalore 560103
Karnataka
India
Email: reji.thomas@arista.com
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