Internet DRAFT - draft-ietf-pim-igmp-mld-extension
draft-ietf-pim-igmp-mld-extension
Network Working Group M. Sivakumar
Internet-Draft Juniper Networks
Intended status: Standards Track S. Venaas
Expires: 5 December 2022 Cisco Systems, Inc.
Z. Zhang
ZTE Corporation
H. Asaeda
NICT
3 June 2022
Internet Group Management Protocol version 3 (IGMPv3) and Multicast
Listener Discovery version 2 (MLDv2) Message Extension
draft-ietf-pim-igmp-mld-extension-08
Abstract
This document specifies a generic mechanism to extend IGMPv3 and
MLDv2 by using a list of TLVs (Type, Length and Value).
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on 5 December 2022.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Provisions Relating to IETF Documents (https://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
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions used in this document . . . . . . . . . . . . . . 3
3. Extension Format . . . . . . . . . . . . . . . . . . . . . . 3
3.1. Multicast Listener Query Extension . . . . . . . . . . . 4
3.2. Version 2 Multicast Listener Report Extension . . . . . . 5
3.3. IGMP Membership Query Extension . . . . . . . . . . . . . 6
3.4. IGMP Version 3 Membership Report Extension . . . . . . . 7
4. No-op TLV . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Processing the extension . . . . . . . . . . . . . . . . . . 9
6. Applicability and backwards compatibility . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
10.1. Normative References . . . . . . . . . . . . . . . . . . 11
10.2. Informative References . . . . . . . . . . . . . . . . . 12
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12
1. Introduction
This document defines a generic method to extend IGMPv3 [RFC3376] and
MLDv2 [RFC3810] messages to accommodate information other than what
is contained in the current message formats. This is done by
allowing a list of TLVs (Type, Length and Value) to be used in the
Additional Data section of IGMPv3 and MLDv2 messages. This document
defines a registry for such TLVs, while other documents will define
the specific types and their values, and their semantics. The
extension would only be used when at least one TLV is to be added to
the message. This extension also applies to the lightweight versions
of IGMPv3 and MLDv2 as defined in [RFC5790].
When this extension mechanism is used, it replaces the Additional
Data section defined in IGMPv3/MLDv2 with TLVs.
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Additional Data is defined for Query messages in IGMPv3 [RFC3376]
Section 4.1.10 and MLDv2 [RFC3810] Section 5.1.12, and for Report
messages in IGMPv3 [RFC3376] Section 4.2.11 and MLDv2 [RFC3810]
Section 5.2.11.
2. Conventions used in this document
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. Extension Format
For each of the IGMPv3 and MLDv2 headers, a previously reserved bit
is used to indicate the presence of this extension. When this
extension is used, the Additional Data of IGMPv3 and MLDv2 messages
is formatted as follows. Note that this format contains a variable
number of TLVs. It MUST contain at least one TLV.
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 Type 1 | Extension Length 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value 1 |
. . .
. . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Type 2 | Extension Length 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value 2 |
. . .
. . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Type n | Extension Length n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value n |
. . .
. . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Figure 1: Extension Format
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Extension Type: 2 octets. This identifies a particular Extension
Type as defined in the IGMP/MLD Extension Type Registry. If this
is not the first TLV, it will follow immediately after the end of
the previous one. There is no alignment or padding.
Extension Length: 2 octets. This specifies the length in octets
of the following Extension Value field. The length may be zero if
no value is needed.
Extension Value: This field contains the value. The length and
the contents of this field is according to the specification of
the Extension Type.
IGMPv3 and MLDv2 messages are defined so that they can fit within the
network MTU, in order to avoid fragmentation. An IGMPv3/MLDv2 report
message contains a number of records. The records are called Group
Records for IGMPv3, and Address Records for MLDv2. When this
extension mechanism is used, the number of records in each Report
message SHOULD be kept small enough that the entire message,
including any extension TLVs can fit within the network MTU.
3.1. Multicast Listener Query Extension
The MLDv2 Query Message format [RFC3810] with extension is shown
below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0.
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 = 130 | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Response Code | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
* *
| |
* Multicast Address *
| |
* *
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Resv|S| QRV | QQIC | Number of Sources (N) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
* *
| |
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* Source Address [1] *
| |
* *
| |
+- -+
| |
* *
| |
* Source Address [2] *
| |
* *
| |
+- . -+
. . .
. . .
+- -+
| |
* *
| |
* Source Address [N] *
| |
* *
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Figure 2: MLD Query Extension
3.2. Version 2 Multicast Listener Report Extension
The MLDv2 Report Message format [RFC3810] with extension is shown
below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0.
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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 = 143 | Reserved | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Reserved |Nr of Mcast Address Records (M)|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Multicast Address Record [1] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Multicast Address Record [2] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
. . .
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Multicast Address Record [M] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Figure 3: MLD Report Extension
3.3. IGMP Membership Query Extension
The IGMPv3 Query Message format [RFC3376] with the extension is shown
below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0.
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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 = 0x11 | Max Resp Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Resv|S| QRV | QQIC | Number of Sources (N) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Address [1] |
+- -+
| Source Address [2] |
+- . -+
. . .
. . .
+- -+
| Source Address [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Figure 4: IGMP Query Extension
3.4. IGMP Version 3 Membership Report Extension
The IGMPv3 Report Message format [RFC3376] with the extension is
shown below. The E-bit MUST be set to 1 to indicate that the
extension is present. Otherwise, it MUST be 0.
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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 = 0x22 | Reserved | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Reserved | Number of Group Records (M) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [1] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [2] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . |
. . .
| . |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Group Record [M] .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension |
~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Figure 5: IGMP Report Extension
4. No-op TLV
The no-op TLV is a No-Operation TLV that MUST be ignored during
processing. This TLV may be useful for verifying that
implementations correctly implement this extension mechanism. Note
that there is no alignment requirement, so there is no need to use
this Extension Type to provide alignment.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| No-op Type = 0 | No-op Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value |
. . .
. . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Figure 6: No-op TLV Format
No-op Type: 2 octets. The type of the No-op TLV extension is the
value 0.
Extension Length: 2 octets. This specifies the length in octets
of the following Value field. The length may be zero if no value
is needed.
Value: This field contains the value. As this Extension Type is
always ignored, the value can be arbitrary data. The number of
octets used MUST match the specified length. contents of this
field is according to the specification of the Extension Type.
5. Processing the extension
The procedure specified in this document applies only when the E-bit
is set.
If the validation of the TLVs fails, the entire Additional Data field
MUST be ignored as specified in IGMPv3 [RFC3376] and MLDv2 [RFC3810].
The following checks must pass for the validation of the TLVs not to
fail:
At least one TLV MUST be present.
There MUST NOT be any data in the IP payload after the last TLV.
To check this, the parser needs to walk through each of the TLVs
until there are less than four octets left in the IP payload. If
there are any octets left, validation fails.
The total length of the Extension MUST NOT exceed the remainder of
the IP payload length. For this validation, one only examines the
content of the Extension Length fields.
Future documents defining a new Extension Type MUST specify any
additional processing and validation. These rules, if any, will be
examined only after the general validation (above) succeeds.
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TLVs with unsupported Extension Types MUST be ignored.
6. Applicability and backwards compatibility
IGMP and MLD implementations, particularly implementations on hosts,
rarely change, and the adoption process of this extension mechanism
is expected to be slow. Also, as new extension TLVs are defined, it
may take a long time before they are supported. Due to this,
defining new extension TLVs should not be taken lightly, and it is
crucial to consider backwards compatibility.
Implementations that do not support this extension mechanism will
ignore it, as specified in [RFC3376] and [RFC3810]. Also, as
mentioned in the previous section, unsupported extension TLVs are
ignored.
It is possible that a new extension TLV only applies to queries, or
only to reports, or there may be other specific conditions for when
it is to be used. A document defining a new Extension Type MUST
specify under what conditions the new Extension Type should be used,
including for which message types. It MUST also be specified what
the behavior should be if a message is not used in the defined
manner, e.g., if it is present in a query message, when it was only
expected to be used in reports.
When defining new Extension Types, care should be taken to consider
the effect of partial support for the new TLV, by either the hosts or
routers, on the same link. Further, it must be considered whether
there are any dependencies or restrictions on combinations between
the new Extension Types and any pre-existing Extension Types.
This document defines an extension mechanism only for IGMPv3 and
MLDv2. Hence, this mechanism does not apply if hosts or routers send
older version messages.
7. Security Considerations
The Security Considerations of [RFC3376] and [RFC3810] also apply
here.
This document extends the IGMP and MLD message formats, allowing for
a variable number of TLVs. Implementations must take care when
parsing the TLVs to not exceed the packet boundary, an attacker could
intentionally specify a TLV with a length exceeding the boundary.
An implementation could add a large number of minimal TLVs in a
message to increase the cost of processing the message to magnify a
Denial of Service attack.
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8. IANA Considerations
IANA is asked to create a new registry called "IGMP/MLD Extension
Types" in the "Internet Group Management Protocol (IGMP) Type
Numbers" section, with registration procedure "IETF Review"
[RFC8126], and with this document as a reference. The registry is
common for IGMP and MLD.
Two Extension Types are provided for "Experimental Use" [RFC8126].
Any experiments should be confined to closed environments where it is
unlikely that they may conflict with other experiments, see
[RFC3692].
The initial content of the registry should be as below.
Extension Type Length Name Reference
--------------------------------------------------------------
0 variable No-op [this document]
1-65533 Unassigned
65534 variable Experimental use
65535 variable Experimental use
9. Acknowledgements
The authors thank Ron Bonica, Ian Duncan, Wesley Eddy, Leonard
Giuliano, Jake Holland, Tommy Pauly, Pete Resnick, Alvaro Retana and
Zhaohui Zhang for reviewing the document and providing valuable
feedback.
10. References
10.1. Normative References
[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/info/rfc2119>.
[RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
Thyagarajan, "Internet Group Management Protocol, Version
3", RFC 3376, DOI 10.17487/RFC3376, October 2002,
<https://www.rfc-editor.org/info/rfc3376>.
[RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener
Discovery Version 2 (MLDv2) for IPv6", RFC 3810,
DOI 10.17487/RFC3810, June 2004,
<https://www.rfc-editor.org/info/rfc3810>.
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[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[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/info/rfc8174>.
10.2. Informative References
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692,
DOI 10.17487/RFC3692, January 2004,
<https://www.rfc-editor.org/info/rfc3692>.
[RFC5790] Liu, H., Cao, W., and H. Asaeda, "Lightweight Internet
Group Management Protocol Version 3 (IGMPv3) and Multicast
Listener Discovery Version 2 (MLDv2) Protocols", RFC 5790,
DOI 10.17487/RFC5790, February 2010,
<https://www.rfc-editor.org/info/rfc5790>.
Authors' Addresses
Mahesh Sivakumar
Juniper Networks
64 Butler St
Milpitas, CA 95035
United States of America
Email: sivakumar.mahesh@gmail.com
Stig Venaas
Cisco Systems, Inc.
Tasman Drive
San Jose, CA 95134
United States of America
Email: stig@cisco.com
Zheng(Sandy) Zhang
ZTE Corporation
No. 50 Software Ave, Yuhuatai District
Nanjing
210000
China
Email: zhang.zheng@zte.com.cn
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Hitoshi Asaeda
National Institute of Information and Communications Technology
4-2-1 Nukui-Kitamachi,
184-8795
Japan
Email: asaeda@nict.go.jp
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