rfc9279.original   rfc9279.txt 
Network Working Group M. Sivakumar Internet Engineering Task Force (IETF) M. Sivakumar
Internet-Draft Juniper Networks Request for Comments: 9279 Juniper Networks
Intended status: Standards Track S. Venaas Category: Standards Track S. Venaas
Expires: 5 December 2022 Cisco Systems, Inc. ISSN: 2070-1721 Cisco Systems, Inc.
Z. Zhang Z. Zhang
ZTE Corporation ZTE Corporation
H. Asaeda H. Asaeda
NICT NICT
3 June 2022 July 2022
Internet Group Management Protocol version 3 (IGMPv3) and Multicast Internet Group Management Protocol Version 3 (IGMPv3) and Multicast
Listener Discovery version 2 (MLDv2) Message Extension Listener Discovery Version 2 (MLDv2) Message Extension
draft-ietf-pim-igmp-mld-extension-08
Abstract Abstract
This document specifies a generic mechanism to extend IGMPv3 and This document specifies a generic mechanism to extend IGMPv3 and
MLDv2 by using a list of TLVs (Type, Length and Value). Multicast Listener Discovery Version 2 (MLDv2) by using a list of
TLVs (Type, Length, and Value).
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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 https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on 5 December 2022. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9279.
Copyright Notice Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Conventions used in this document . . . . . . . . . . . . . . 3 2. Conventions Used in This Document
3. Extension Format . . . . . . . . . . . . . . . . . . . . . . 3 3. Extension Format
3.1. Multicast Listener Query Extension . . . . . . . . . . . 4 3.1. Multicast Listener Query Extension
3.2. Version 2 Multicast Listener Report Extension . . . . . . 5 3.2. Version 2 Multicast Listener Report Extension
3.3. IGMP Membership Query Extension . . . . . . . . . . . . . 6 3.3. IGMP Membership Query Extension
3.4. IGMP Version 3 Membership Report Extension . . . . . . . 7 3.4. IGMP Version 3 Membership Report Extension
4. No-op TLV . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4. No-op TLV
5. Processing the extension . . . . . . . . . . . . . . . . . . 9 5. Processing the Extension
6. Applicability and backwards compatibility . . . . . . . . . . 10 6. Applicability and Backwards Compatibility
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 8. IANA Considerations
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11 9. References
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 9.1. Normative References
10.1. Normative References . . . . . . . . . . . . . . . . . . 11 9.2. Informative References
10.2. Informative References . . . . . . . . . . . . . . . . . 12 Acknowledgements
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses
1. Introduction 1. Introduction
This document defines a generic method to extend IGMPv3 [RFC3376] and This document defines a generic method to extend IGMPv3 [RFC3376] and
MLDv2 [RFC3810] messages to accommodate information other than what MLDv2 [RFC3810] messages to accommodate information other than what
is contained in the current message formats. This is done by 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 allowing a list of TLVs to be used in the Additional Data section of
Additional Data section of IGMPv3 and MLDv2 messages. This document IGMPv3 and MLDv2 messages. This document defines a registry for such
defines a registry for such TLVs, while other documents will define TLVs. Other documents will define their specific types, and their
the specific types and their values, and their semantics. The values and semantics. The extension would only be used when at least
extension would only be used when at least one TLV is to be added to one TLV is to be added to the message. This extension also applies
the message. This extension also applies to the lightweight versions to the lightweight versions of IGMPv3 and MLDv2 as defined in
of IGMPv3 and MLDv2 as defined in [RFC5790]. [RFC5790].
When this extension mechanism is used, it replaces the Additional When this extension mechanism is used, it replaces the Additional
Data section defined in IGMPv3/MLDv2 with TLVs. Data section defined in IGMPv3/MLDv2 with TLVs.
Additional Data is defined for Query messages in IGMPv3 [RFC3376] Additional Data is defined for Query messages in IGMPv3
Section 4.1.10 and MLDv2 [RFC3810] Section 5.1.12, and for Report (Section 4.1.10 of [RFC3376]) and MLDv2 (Section 5.1.12 of
messages in IGMPv3 [RFC3376] Section 4.2.11 and MLDv2 [RFC3810] [RFC3810]), and for Report messages in IGMPv3 (Section 4.2.11 of
Section 5.2.11. [RFC3376]) and MLDv2 (Section 5.2.11 of [RFC3810]).
2. Conventions used in this document 2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14 [RFC2119] [RFC8174] when, and only when, they appear in all BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
3. Extension Format 3. Extension Format
For each of the IGMPv3 and MLDv2 headers, a previously reserved bit For each of the IGMPv3 and MLDv2 headers, a previously reserved bit
is used to indicate the presence of this extension. When this is used to indicate the presence of this extension. When this
extension is used, the Additional Data of IGMPv3 and MLDv2 messages extension is used, the Additional Data of IGMPv3 and MLDv2 messages
is formatted as follows. Note that this format contains a variable is formatted as follows. Note that this format contains a variable
number of TLVs. It MUST contain at least one TLV. number of TLVs. It MUST contain at least one TLV.
0 1 2 3 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 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 Type 1 | Extension Length 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value 1 | | Extension Value 1 |
. . . . . .
. . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Type 2 | Extension Length 2 | | Extension Type 2 | Extension Length 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value 2 | | Extension Value 2 |
. . . . . .
. . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Type n | Extension Length n | | Extension Type n | Extension Length n |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension Value n | | Extension Value n |
. . . . . .
. . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Figure 1: Extension Format Figure 1: Extension Format
Extension Type: 2 octets. This identifies a particular Extension Extension Type: 2 octets. This identifies a particular Extension
Type as defined in the IGMP/MLD Extension Type Registry. If this Type as defined in the "IGMP/MLD Extension Types" registry. If
is not the first TLV, it will follow immediately after the end of this is not the first TLV, it will follow immediately after the
the previous one. There is no alignment or padding. end of the previous one. There is no alignment or padding.
Extension Length: 2 octets. This specifies the length in octets Extension Length: 2 octets. This specifies the length in octets of
of the following Extension Value field. The length may be zero if the following Extension Value field. The length may be zero if no
no value is needed. value is needed.
Extension Value: This field contains the value. The length and Extension Value: This field contains the value. The specification
the contents of this field is according to the specification of defining the Extension Type describes the length and contents of
the Extension Type. this field.
IGMPv3 and MLDv2 messages are defined so that they can fit within the IGMPv3 and MLDv2 messages are defined so they can fit within the
network MTU, in order to avoid fragmentation. An IGMPv3/MLDv2 report network MTU in order to avoid fragmentation. An IGMPv3/MLDv2 Report
message contains a number of records. The records are called Group message contains a number of records. The records are called Group
Records for IGMPv3, and Address Records for MLDv2. When this Records for IGMPv3 and Address Records for MLDv2. When this
extension mechanism is used, the number of records in each Report extension mechanism is used, the number of records in each Report
message SHOULD be kept small enough that the entire message, message SHOULD be kept small enough so that the entire message,
including any extension TLVs can fit within the network MTU. including any extension TLVs, can fit within the network MTU.
3.1. Multicast Listener Query Extension 3.1. Multicast Listener Query Extension
The MLDv2 Query Message format [RFC3810] with extension is shown 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 below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0. present. Otherwise, it MUST be 0.
0 1 2 3 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 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 | | Type = 130 | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Response Code | Reserved | | Maximum Response Code | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 5, line 32 skipping to change at line 206
| | | |
* Source Address [N] * * Source Address [N] *
| | | |
* * * *
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | | Extension |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Figure 2: MLD Query Extension Figure 2: MLD Query Extension
3.2. Version 2 Multicast Listener Report Extension 3.2. Version 2 Multicast Listener Report Extension
The MLDv2 Report Message format [RFC3810] with extension is shown 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 below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0. present. Otherwise, it MUST be 0.
0 1 2 3 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 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 | | Type = 143 | Reserved | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Reserved |Nr of Mcast Address Records (M)| |E| Reserved |Nr of Mcast Address Records (M)|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 6, line 38 skipping to change at line 247
| | | |
. . . .
. Multicast Address Record [M] . . Multicast Address Record [M] .
. . . .
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | | Extension |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Figure 3: MLD Report Extension Figure 3: MLD Report Extension
3.3. IGMP Membership Query Extension 3.3. IGMP Membership Query Extension
The IGMPv3 Query Message format [RFC3376] with the extension is shown 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 below. The E-bit MUST be set to 1 to indicate that the extension is
present. Otherwise, it MUST be 0. present. Otherwise, it MUST be 0.
0 1 2 3 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 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 | | Type = 0x11 | Max Resp Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Group Address | | Group Address |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 7, line 27 skipping to change at line 277
+- . -+ +- . -+
. . . . . .
. . . . . .
+- -+ +- -+
| Source Address [N] | | Source Address [N] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | | Extension |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Figure 4: IGMP Query Extension Figure 4: IGMP Query Extension
3.4. IGMP Version 3 Membership Report Extension 3.4. IGMP Version 3 Membership Report Extension
The IGMPv3 Report Message format [RFC3376] with the extension is The IGMPv3 Report message format [RFC3376] with the extension is
shown below. The E-bit MUST be set to 1 to indicate that the shown below. The E-bit MUST be set to 1 to indicate that the
extension is present. Otherwise, it MUST be 0. extension is present. Otherwise, it MUST be 0.
0 1 2 3 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 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 | | Type = 0x22 | Reserved | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|E| Reserved | Number of Group Records (M) | |E| Reserved | Number of Group Records (M) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 8, line 38 skipping to change at line 318
| | | |
. . . .
. Group Record [M] . . Group Record [M] .
. . . .
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extension | | Extension |
~ ~ ~ ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Figure 5: IGMP Report Extension Figure 5: IGMP Report Extension
4. No-op TLV 4. No-op TLV
The no-op TLV is a No-Operation TLV that MUST be ignored during The No-op TLV is a No-Operation TLV that MUST be ignored during
processing. This TLV may be useful for verifying that processing. This TLV may be used to verify that the extension
implementations correctly implement this extension mechanism. Note mechanism has been implemented correctly. Note that there is no
that there is no alignment requirement, so there is no need to use alignment requirement, so there is no need to use this Extension Type
this Extension Type to provide alignment. to provide alignment.
0 1 2 3 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 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 | | No-op Type = 0 | No-op Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value | | Value |
. . . . . .
. . . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Figure 6: No-op TLV Format Figure 6: No-op TLV Format
No-op Type: 2 octets. The type of the No-op TLV extension is the No-op Type: 2 octets. The type of the No-op TLV extension is 0.
value 0.
Extension Length: 2 octets. This specifies the length in octets Extension Length: 2 octets. This specifies the length in octets of
of the following Value field. The length may be zero if no value the following Value field. The length may be zero if no value is
is needed. needed.
Value: This field contains the value. As this Extension Type is Value: This field contains the value. As this Extension Type is
always ignored, the value can be arbitrary data. The number of always ignored, the value can be arbitrary data. The number of
octets used MUST match the specified length. contents of this octets used MUST match the specified length.
field is according to the specification of the Extension Type.
5. Processing the extension 5. Processing the Extension
The procedure specified in this document applies only when the E-bit The procedure specified in this document only applies when the E-bit
is set. is set.
If the validation of the TLVs fails, the entire Additional Data field If the validation of the TLVs fails, the entire Additional Data field
MUST be ignored as specified in IGMPv3 [RFC3376] and MLDv2 [RFC3810]. MUST be ignored as specified in IGMPv3 [RFC3376] and MLDv2 [RFC3810].
The following checks must pass for the validation of the TLVs not to The following checks must pass for the validation of the TLVs not to
fail: fail:
At least one TLV MUST be present. * At least one TLV MUST be present.
There MUST NOT be any data in the IP payload after the last TLV. * 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 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 until there are less than four octets left in the IP payload. If
there are any octets left, validation fails. there are any octets left, validation fails.
The total length of the Extension MUST NOT exceed the remainder of * The total length of the Extension MUST NOT exceed the remainder of
the IP payload length. For this validation, one only examines the the IP payload length. For this validation, only the content of
content of the Extension Length fields. the Extension Length fields is examined.
Future documents defining a new Extension Type MUST specify any Future documents defining a new Extension Type MUST specify any
additional processing and validation. These rules, if any, will be additional processing and validation. These rules, if any, will be
examined only after the general validation (above) succeeds. examined only after the general validation succeeds.
TLVs with unsupported Extension Types MUST be ignored. TLVs with unsupported Extension Types MUST be ignored.
6. Applicability and backwards compatibility 6. Applicability and Backwards Compatibility
IGMP and MLD implementations, particularly implementations on hosts, IGMP and MLD implementations, particularly implementations on hosts,
rarely change, and the adoption process of this extension mechanism rarely change. The adoption process of this extension mechanism is
is expected to be slow. Also, as new extension TLVs are defined, it expected to be slow. As new extension TLVs are defined, it may take
may take a long time before they are supported. Due to this, a long time for them to be supported. Due to this, defining new
defining new extension TLVs should not be taken lightly, and it is extension TLVs should not be taken lightly, and it is crucial to
crucial to consider backwards compatibility. consider backwards compatibility.
Implementations that do not support this extension mechanism will Implementations that do not support this extension mechanism will
ignore it, as specified in [RFC3376] and [RFC3810]. Also, as ignore it, as specified in [RFC3376] and [RFC3810]. As mentioned in
mentioned in the previous section, unsupported extension TLVs are the previous section, unsupported extension TLVs are ignored.
ignored.
It is possible that a new extension TLV only applies to queries, or It is possible that a new extension TLV will only apply to queries or
only to reports, or there may be other specific conditions for when only to reports, or that there may be other specific conditions for
it is to be used. A document defining a new Extension Type MUST 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, specify the conditions under which the new Extension Type should be
including for which message types. It MUST also be specified what used, including which message types. It MUST also be specified what
the behavior should be if a message is not used in the defined 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 manner, e.g., if it is present in a Query message, when it was only
expected to be used in reports. expected to be used in reports.
When defining new Extension Types, care should be taken to consider When defining new Extension Types, the effect of partial support for
the effect of partial support for the new TLV, by either the hosts or the new TLV, by either the hosts or routers, on the same link should
routers, on the same link. Further, it must be considered whether be carefully considered. Further, whether there are any dependencies
there are any dependencies or restrictions on combinations between or restrictions on combinations between the new Extension Types and
the new Extension Types and any pre-existing Extension Types. any preexisting Extension Types must be considered.
This document defines an extension mechanism only for IGMPv3 and This document defines an extension mechanism only for IGMPv3 and
MLDv2. Hence, this mechanism does not apply if hosts or routers send MLDv2. Hence, this mechanism does not apply if hosts or routers send
older version messages. older version messages.
7. Security Considerations 7. Security Considerations
The Security Considerations of [RFC3376] and [RFC3810] also apply The Security Considerations of [RFC3376] and [RFC3810] also apply
here. here.
This document extends the IGMP and MLD message formats, allowing for This document extends the IGMP and MLD message formats, allowing for
a variable number of TLVs. Implementations must take care when a variable number of TLVs. Implementations must take care not to
parsing the TLVs to not exceed the packet boundary, an attacker could exceed the packet boundary when parsing the TLVs, because an attacker
intentionally specify a TLV with a length exceeding the boundary. could intentionally specify a TLV with a length exceeding the
boundary.
An implementation could add a large number of minimal TLVs in a An implementation could add a large number of minimal TLVs in a
message to increase the cost of processing the message to magnify a message to increase the cost of processing the message. This would
Denial of Service attack. magnify a denial-of-service attack.
8. IANA Considerations 8. IANA Considerations
IANA is asked to create a new registry called "IGMP/MLD Extension IANA has created a new registry called "IGMP/MLD Extension Types" in
Types" in the "Internet Group Management Protocol (IGMP) Type the "Internet Group Management Protocol (IGMP) Type Numbers" section
Numbers" section, with registration procedure "IETF Review" and lists this document as the reference. The registration procedure
[RFC8126], and with this document as a reference. The registry is is "IETF Review" [RFC8126]. The registry is common for IGMP and MLD.
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. Two Extension Types (65534 and 65535) 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].
Extension Type Length Name Reference IANA has initially populated the registry as shown in Table 1
--------------------------------------------------------------
0 variable No-op [this document]
1-65533 Unassigned
65534 variable Experimental use
65535 variable Experimental use
9. Acknowledgements +================+==========+==================+===========+
| Extension Type | Length | Name | Reference |
+================+==========+==================+===========+
| 0 | variable | No-op | RFC 9279 |
+----------------+----------+------------------+-----------+
| 1-65533 | | Unassigned | |
+----------------+----------+------------------+-----------+
| 65534-65535 | variable | Reserved for | |
| | | Experimental Use | |
+----------------+----------+------------------+-----------+
The authors thank Ron Bonica, Ian Duncan, Wesley Eddy, Leonard Table 1: IGMP/MLD Extension Types
Giuliano, Jake Holland, Tommy Pauly, Pete Resnick, Alvaro Retana and
Zhaohui Zhang for reviewing the document and providing valuable
feedback.
10. References 9. References
10.1. Normative References 9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A. [RFC3376] Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
Thyagarajan, "Internet Group Management Protocol, Version Thyagarajan, "Internet Group Management Protocol, Version
3", RFC 3376, DOI 10.17487/RFC3376, October 2002, 3", RFC 3376, DOI 10.17487/RFC3376, October 2002,
<https://www.rfc-editor.org/info/rfc3376>. <https://www.rfc-editor.org/info/rfc3376>.
skipping to change at page 12, line 14 skipping to change at line 479
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
10.2. Informative References 9.2. Informative References
[RFC3692] Narten, T., "Assigning Experimental and Testing Numbers [RFC3692] Narten, T., "Assigning Experimental and Testing Numbers
Considered Useful", BCP 82, RFC 3692, Considered Useful", BCP 82, RFC 3692,
DOI 10.17487/RFC3692, January 2004, DOI 10.17487/RFC3692, January 2004,
<https://www.rfc-editor.org/info/rfc3692>. <https://www.rfc-editor.org/info/rfc3692>.
[RFC5790] Liu, H., Cao, W., and H. Asaeda, "Lightweight Internet [RFC5790] Liu, H., Cao, W., and H. Asaeda, "Lightweight Internet
Group Management Protocol Version 3 (IGMPv3) and Multicast Group Management Protocol Version 3 (IGMPv3) and Multicast
Listener Discovery Version 2 (MLDv2) Protocols", RFC 5790, Listener Discovery Version 2 (MLDv2) Protocols", RFC 5790,
DOI 10.17487/RFC5790, February 2010, DOI 10.17487/RFC5790, February 2010,
<https://www.rfc-editor.org/info/rfc5790>. <https://www.rfc-editor.org/info/rfc5790>.
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.
Authors' Addresses Authors' Addresses
Mahesh Sivakumar Mahesh Sivakumar
Juniper Networks Juniper Networks
64 Butler St 64 Butler St
Milpitas, CA 95035 Milpitas, CA 95035
United States of America United States of America
Email: sivakumar.mahesh@gmail.com Email: sivakumar.mahesh@gmail.com
Stig Venaas Stig Venaas
Cisco Systems, Inc. Cisco Systems, Inc.
Tasman Drive Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
United States of America United States of America
Email: stig@cisco.com Email: stig@cisco.com
Zheng(Sandy) Zhang Zheng(Sandy) Zhang
ZTE Corporation ZTE Corporation
No. 50 Software Ave, Yuhuatai District No. 50 Software Ave, Yuhuatai District
Nanjing Nanjing
210000 210000
China China
Email: zhang.zheng@zte.com.cn Email: zhang.zheng@zte.com.cn
skipping to change at page 13, line 4 skipping to change at line 522
United States of America United States of America
Email: stig@cisco.com Email: stig@cisco.com
Zheng(Sandy) Zhang Zheng(Sandy) Zhang
ZTE Corporation ZTE Corporation
No. 50 Software Ave, Yuhuatai District No. 50 Software Ave, Yuhuatai District
Nanjing Nanjing
210000 210000
China China
Email: zhang.zheng@zte.com.cn Email: zhang.zheng@zte.com.cn
Hitoshi Asaeda Hitoshi Asaeda
National Institute of Information and Communications Technology National Institute of Information and Communications Technology
4-2-1 Nukui-Kitamachi, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo
184-8795 184-8795
Japan Japan
Email: asaeda@nict.go.jp Email: asaeda@nict.go.jp
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