MPLS Working Group L. Andersson
Internet-Draft Bronze Dragon Consulting
Updates: 8029, 8611 (if approved) M. Chen
Intended status: Standards Track Huawei Techologies
Expires: February 18, 2021 C. Pignataro
Cisco Systems
T. Saad
Juniper Networks
August 17, 2020
Updating the IANA MPLS LSP Ping Parameters
draft-ietf-mpls-lsp-ping-registries-update-03
Abstract
This document updates RFC 8029 and RFC 8611 that both define IANA
registries for MPLS LSP Ping. It also updates the description of the
procedures for the responses sent when an unknown or erroneous code
point is found. The updates are to clarify and align this name space
with recent developments.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on February 18, 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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
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carefully, as they describe your rights and restrictions with respect
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirement Language . . . . . . . . . . . . . . . . . . 3
2. Updating the Message Types, Reply Mode and Return Codes
Registries . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Updating the TLV and sub-TLV registries . . . . . . . . . . . 4
3.1. General principles the LSP Ping TLV and sub-TLV
registries . . . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. Unrecognized Experimental Use TLVs and sub-TLVs . . . 5
3.2. Changes to the LSP Ping Registries . . . . . . . . . . . 5
3.2.1. Common Changes to the TLV and sub-TLV Registries . . 5
4. Updates to Related RFCs . . . . . . . . . . . . . . . . . . . 6
4.1. Updates to RFC 8029 . . . . . . . . . . . . . . . . . . . 6
4.2. Updates to RFC 8611 . . . . . . . . . . . . . . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6.1. Updates of Message Type, Reply Mode and Return Codes
Registries . . . . . . . . . . . . . . . . . . . . . . . 9
6.2. Common Registration Procedures for TLVs and sub-TLVs . . 9
6.3. IANA Assignments for TLVs and sub-TLVs . . . . . . . . . 10
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 11
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction
When RFC 8029 [RFC8029] was published it contained updates to the
"Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs)
Ping Parameters" IANA name space [IANA-LSP-PING].
RFC 8611 [RFC8611] updated the LSP Ping IANA registries to match RFC
8029. This document further clarifies the entries in those
registries and makes the definitions more precise.
This document updates RFC 8029 [[RFC8029] and RFC 8611 [RFC8611] by
updating two groups of registries as follows:
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First the registries for Message Types [IANA-MT], Reply Modes
[IANA-RM] and Return Codes [IANA-RC] are updated. The changes to
these registries are minor.
Second, this document updates the TLV and sub-TLV registries.
o TLVs [IANA-TLV-reg]
o Sub-TLVs for TLVs 1, 16 and 21 [IANA-Sub-1-16-21]
o Sub-TLVs for TLV 6 [IANA-Sub-6]
o Sub-TLVs for TLV 11 [IANA-Sub-11]
o Sub-TLVs for TLV 20 [IANA-Sub-20]
o Sub-TLVs for TLV 23 [IANA-Sub-23]
o Sub-TLVs for TLV 27 [IANA-Sub-27]
The registry for sub-TLVs for TLV 9 [IANA-Sub-9] is not updated.
Third, some code points (TLVs and sub-TLVs) are "mandatory" or
"optional". Contrary to how other RFCs use these words, indicating
that it is mandatory or optional to include the code points in a
message, RFC 8029 use the words to indicate that an action might or
might not be necessary. This document drops the words "mandatory and
"optional" and the text is changed to focus on what should be done.
1.1. Requirement Language
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.
2. Updating the Message Types, Reply Mode and Return Codes Registries
The following changes are made to the Message Types, Reply Modes and
Return Codes [IANA-MT] registries.
o in the listing of assiged code points the term "Vendor Private
Use" is changed to "Private Use".
o the registration procedure "Specification Required" is changed to
"RFC Required" and the note "Experimental RFC needed" is removed
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o a small set of code points (4 code points) for Experimental Use is
added by reducing the range for "RFC Required" range.
o the registration procedures "Private Use" and "Experimental Use"
are added to the table of registration procedures
o A note "Not to be assigned" is added for the registration
procedures "Private Use" and "Experimental Use"
o In the lists that capture the assignment status, the fields that
are reserved, i.e. 0 (zero), Private Use and Experimental Use are
clearly marked as such.
* In the Return Codes [IANA-RC] [IANA-RC] registry the code point
"0" has already been assigned. This assignment is not changed
and in this registry the code point "0" continues to be
assigned as "No Return Code".
The new Registration Procedures, the registry layouts and the new
assignments for these registries will be found in Section 6.1.
3. Updating the TLV and sub-TLV registries
3.1. General principles the LSP Ping TLV and sub-TLV registries
The following principles are valid for all the LSP Ping TLV and sub-
TLV IANA registries
o all TLVs and sub-TLVs with a type in the range 0-32767 require a
response if they are not recognized
o all TLVs and sub-TLVs in the range 32768-65535 may be silently
dropped if they are not recognized
The range of each TLV and sub-TLV registry is divided into two
blocks, one with a range from 0 to 32767 for TLVs and sub-TLVs that
require a response if not recognized. The other block in the range
from 32768 to 65535 for TLVs and sub-TLVs that may be silently
dropped, possibly stepped over, if not recognized.
Each of the blocks has code point spaces with the following
registration procedures:
o Standards Action
o RFC Required
o Experimental Use
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o First come, first served (FCFS)
The exact defintions of these procedures are found in [RFC8126]
3.1.1. Unrecognized Experimental Use TLVs and sub-TLVs
Unrecognized TLVs and sub-TLVs in the Experimetal Use, and FCFS
ranges are handled as any other unrecognized TLV or sub-TLV.
o If the unrecognized TLV or sub-TLV is from the Experimental Use
range (37140-37143) or from the FCFS range (31744-32767) a the
Return Code of 2 ("One or more of the TLVs was not understood")
will be sent in the echo response.
o If the unrecognized TLV or sub-TLV is from the Experimental Use
range (64508-64511) or from the Private Use range (64512-65535)
the TLVs SHOULD be silently ignored and possibly be stepped over.
IETF does not prescribe how recognized or unrecognized Experimental
Use and Private Use TLVs and sub-TLVs are handled in experimental or
private networks, that is up to the agency running the experiment or
the private network. The statement above describes how standards
compliant implementations will treat the unrecognized TLVs and sub-
TLVs from these ranges.
3.2. Changes to the LSP Ping Registries
This section lists the changes to each MPLS LSP Ping TLV and sub-TLV
Registry. Section 6.1, Section 6.2 and Section 6.3 outline how the
new versions of the IANA registries should look, together with the
registration procedures for each registry.
3.2.1. Common Changes to the TLV and sub-TLV Registries
The following changes are made to the TLV and sub-TLV registries.
o the registration procedures "First Come Frst Served (FCFS)" and
"Experimental Use" are added to the table of registration
procedures
o two small sets of code points (4 code points each) for
Experiemental Use are created. The first set are for the range
that requires a response if the TLV or sub-TLV is not recognised;
the sedond set are for the range there the TLV or sub-TLV that MAY
be silently dropped if not recognized. The code points for
experimental use are actually taken from the two ranges now called
"RFC Required".
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o the registration procedure "Specification Required" is changed to
"RFC Required" and the note "Experimental RFC needed" is removed
o In the listing of assignments the term "Vendor Private Use" is
changed to "First Come First Served (FCFS)"
o In the listing of assignments the range for "Experimental Use" is
added
o A note saying "Not to be assigned" is added for the registration
procedures "Experimental Use"
o In the list that capture assignment status, the fields that are
reserved, i.e. 0 (zero) and Experimental Use are clearly marked.
The new Registration Procedures description and the new assignments
for these registries are shown in Section 6.2 and Section 6.3.
4. Updates to Related RFCs
Some referenced RFCs are using the concept "mandatory TLVs" and
"mandatory sub-TLVs" to indicate that, if a TLV or sub-TLV of the
range 0-16383 or 16384-31743 in a message is not understood, an error
message needs to be sent in response.
The same RFCs use "optional TLVs" and "optional sub-TLVs" to mean
TLVs or sub-TLVs that can be silently ignored if not recognized.
Since other RFCs use "mandatory TLVs" and "mandatory sub-TLVs" to
indicate TLVs and sub-TLVs that must be present in a message, we want
to discontinue the use of "mandatory" to indicate TLVs and sub-TLVs
that requires an error message in response if not understood. The
changes to the RFCs below are intended to align with this practice.
4.1. Updates to RFC 8029
Mandatory and optional is used to indicate whether are response ir
needed or if at TLV or sub-TLV is not understoond page 14 and 15 in
Section 3 of RFC 8029.
The text in those two paragraphs are now updated to the following:
TLV and sub-TLV Types less than 32768 (i.e., with the high-order
bit equal to 0) are TLVs and sub-TLVs that MUST either be
supported by an implementation or result in the Return Code of 2
("One or more of the TLVs was not understood") being sent in the
echo response.
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An implementation that does not understand or support a received
TLV or sub-TLV with Type greater than or equal to 32768 (i.e.,
with the high-order bit equal to 1) SHOULD ignore and step over
the TLV or sub-TLV, however an implementation MAY send an echo
response with Return Code 2 ("One or more of the TLVs was not
understood") as it would have done if the high order bit had been
clear.
In Section 3.8 of RFC 8029 "mandatory" is used in the same way. The
first two paragraphs of this section are now updated to read as
follows:
The following TLV is a TLV that MAY be included in an echo reply
to inform the sender of an echo request that includes TLVs or sub-
TLVs Types greater than or equal to 32768 (i.e., with the high-
order bit equal to 1) are either not supported by the
implementation or parsed and found to be in error.
The Value field contains the TLVs, including sub-TLVs, that were
not understood, encoded as sub-TLVs.
4.2. Updates to RFC 8611
The "Sub-TLVs for TLV Type 6" registry is now updated to align with
changes defined in this document.
The registration procedures for the "Sub-TLVs for TLV Type 6"
registry will now be as follows:
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+-------------+-------------------+---------------------------------+
| Range | Registration | Note |
| | Procedures | |
+-------------+-------------------+---------------------------------+
| 0-16383 | Standards Action | This range is for sub-TLVs that |
| | | require an error message if not |
| | | recognized. |
| 16384-31739 | RFC Required | This range is for sub-TLVs that |
| | | require an error message if not |
| | | recognized. |
| 31740-31743 | Experimental Use | Reserved not to be assigned |
| 31744-32767 | FCFS | This range is for sub-TLVs that |
| | | require an error message if not |
| | | recognized. |
| 32768-49161 | Standards Action | This range is for sub-TLVs that |
| | | can be silently dropped if not |
| | | recognized. |
| 49162-64507 | RFC Required | This range is for sub-TLVs that |
| | | can be silently dropped if not |
| | | recognized. |
| 64508-64511 | Experimental Use | Reserved not to be assigned |
| 64512-65535 | FCFS | This range is for sub-TLVs that |
| | | can be silently dropped if not |
| | | recognized. |
+-------------+-------------------+---------------------------------+
Sub-TLVs for TLV Type 6 Registration Procedures
5. Security Considerations
This document updates IANA registries. It also updates terminology
used to define, and clarifies the terminology related to the code
points in the registries. The document does not change how the code-
points in the registries are used. This should not create any new
threats.
However, the updated terminology and the clarifications improve
security because it makes it more likely that implementations will be
consistent and harder to attack.
6. IANA Considerations
IANA is requested to update the LSP Ping name space as described in
this document.
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6.1. Updates of Message Type, Reply Mode and Return Codes Registries
This section details the updated registration procedures and
allocations for Message Type, Reply Mode and Return Codes registries.
+---------+--------------------+------------------------------------+
| Range | Registration | Note |
| | Procedures | |
+---------+--------------------+------------------------------------+
| 0-191 | Standards Action | |
| 192-247 | RFC Required | |
| 248-251 | Experimental Use | Not to be assigned |
| 252-255 | Private Use | Not to be assigned |
+---------+--------------------+------------------------------------+
New common registration procedures
+---------+---------------------------------+-----------------------+
| Value | Meaning | Reference |
+---------+---------------------------------+-----------------------+
| 0 | Reserved | This document |
| 1-247 | No changes to the existing | |
| | assignments | |
| 248-251 | Reserved for Experimental Use | This document |
| 252-255 | Reserved for Private Use | [RFC8029] |
+---------+---------------------------------+-----------------------+
Common Assignments for the Message Types, Reply Mode and Return Code
registries
Note that for the Return Code registry an assignment for code point
zero has been previously msde, it is not changed but remains:
+-------+----------------------------------+------------------------+
| Value | Meaning | Reference |
+-------+----------------------------------+------------------------+
| 0 | No return code | [RFC8029] |
+-------+----------------------------------+------------------------+
Assignment for code point 0 in the Return Code registry
6.2. Common Registration Procedures for TLVs and sub-TLVs
This section describes the new registration procedures for the TLV
and sub-TLV registries. The registry for sub-TLV 9 ([IANA-Sub-9] is
not changed.
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+-------------+-------------------+---------------------------------+
| Range | Registration | Note |
| | Procedures | |
+-------------+-------------------+---------------------------------+
| 0-16383 | Standards Action | This range is for TLVs anf sub- |
| | | TLVs that require an error |
| | | message if not recognized. |
| 16384-31739 | RFC Required | This range is for TLVs anf sub- |
| | | TLVs that require an error |
| | | message if not recognized. |
| 37140-37144 | Experimental Use | Rserved, not to be assigned |
| 31748-32767 | FCFS | This range is for TLVs anf sub- |
| | | TLVs that require an error |
| | | message if not recognized. |
| 32768-49161 | Standards Action | This range is for TLVs and sub- |
| | | TLVs that can be silently |
| | | dropped if not recognized. |
| 49162-64507 | RFC Required | This range is for TLVs and sub- |
| | | TLVs that can be silently |
| | | dropped if not recognized. |
| 64508-64511 | Experimental Use | Rserved, not to be assigned |
| 64512-65535 | FCFS | This range is for TLVs and sub- |
| | | TLVs that can be silently |
| | | dropped if not recognized. |
+-------------+-------------------+---------------------------------+
TLV and sub-TLV Registration Procedures
6.3. IANA Assignments for TLVs and sub-TLVs
The two tables in this section describes the updated IANA assignments
for the TLV and sub-TLV registries. The registry for sub-TLV 9
([IANA-Sub-9] is not changed.
Updated TLV assignments are as follows:
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+--------------+------------------+------------------+--------------+
| Type | TLV name | Reference | sub-TLV |
| | | | registry |
+--------------+------------------+------------------+--------------+
| 0 | Reserved | This document | |
| 1-31739 | [any] | No changes to | [any] |
| | | the current | |
| | | registry | |
| 37140-37143 | Reserved for | This document | NA |
| | Experimental Use | | |
| 31744-32767 | FCFS | This document | NA |
| 32768-64507 | [any] | No changes to | [any] |
| | | the current | |
| | | registry. | |
| 64508-64511 | Reserved for | This document | NA |
| | Experimental Use | | |
| 645152-65535 | FCFS | This document | NA |
+--------------+------------------+------------------+--------------+
TLV Assignments
Updated Sub-TLV assignments are as follows:
+-------------+-------------------------------+---------------------+
| Type | TLV name | Reference |
+-------------+-------------------------------+---------------------+
| 0 | Reserved | This document |
| 1-31739 | [any] | No changes to the |
| | | current registry |
| 37140-37143 | Reserved for Experimental Use | This document |
| 31744-32767 | FCFS | This document |
| 32768-64507 | [any] | No changes to the |
| | | current registry. |
| 64508-64511 | Reserved for Experimental Use | This document |
| 64512-65535 | FSFC | This document |
+-------------+-------------------------------+---------------------+
Sub-TLV Assignments
7. Acknowledgements
The authors wish to thank Adrian Farrel, who both made very useful
comments and agreed to serve as the document shepherd.
The authors also wish to thank Micelle Cotton who very patiently
worked with us to determine how our registries could and should be
updated.
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The authors thanks Donald Eatlake for a careful and detailed review.
8. References
8.1. Normative References
[IANA-LSP-PING]
"Multiprotocol Label Switching (MPLS) Label Switched Paths
(LSPs) Ping Parameters",
.
[IANA-MT] "Message Types", .
[IANA-RC] "Return Codes", .
[IANA-RM] "Reply Modes", .
[IANA-Sub-1-16-21]
"Sub-TLVs for TLV Types 1, 16, and 21",
.
[IANA-Sub-11]
"Sub-TLVs for TLV Type 11",
.
[IANA-Sub-20]
"Sub-TLVs for TLV Type 20",
.
[IANA-Sub-23]
"Sub-TLVs for TLV Type 23",
.
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[IANA-Sub-27]
"Sub-TLVs for TLV Type 27",
.
[IANA-Sub-6]
"Sub-TLVs for TLV Type 6",
.
[IANA-TLV-reg]
"TLVs", .
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
Switched (MPLS) Data-Plane Failures", RFC 8029,
DOI 10.17487/RFC8029, March 2017,
.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, .
[RFC8611] Akiya, N., Swallow, G., Litkowski, S., Decraene, B.,
Drake, J., and M. Chen, "Label Switched Path (LSP) Ping
and Traceroute Multipath Support for Link Aggregation
Group (LAG) Interfaces", RFC 8611, DOI 10.17487/RFC8611,
June 2019, .
8.2. Informative References
[IANA-Sub-9]
"Sub-TLVs for TLV Type 9",
.
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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,
.
Authors' Addresses
Loa Andersson
Bronze Dragon Consulting
Email: loa@pi.nu
Mach Chen
Huawei Techologies
Email: mach.chen@huawei.com
Carlos Pignataro
Cisco Systems
Email: cpignata@cisco.com
Tarek Saad
Juniper Networks
Email: tsaad@juniper.net
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