draft-ietf-mpls-lsp-ping-lag-multipath-05.txt   draft-ietf-mpls-lsp-ping-lag-multipath-06.txt 
Internet Engineering Task Force N. Akiya Internet Engineering Task Force N. Akiya
Internet-Draft Big Switch Networks Internet-Draft Big Switch Networks
Updates: 8029 (if approved) G. Swallow Updates: 8029 (if approved) G. Swallow
Intended status: Standards Track Cisco Systems Intended status: Standards Track Cisco Systems
Expires: April 26, 2019 S. Litkowski Expires: September 6, 2019 S. Litkowski
B. Decraene B. Decraene
Orange Orange
J. Drake J. Drake
Juniper Networks Juniper Networks
M. Chen M. Chen
Huawei Huawei
October 23, 2018 March 05, 2019
Label Switched Path (LSP) Ping/Trace Multipath Support for Label Switched Path (LSP) Ping/Trace Multipath Support for
Link Aggregation Group (LAG) Interfaces Link Aggregation Group (LAG) Interfaces
draft-ietf-mpls-lsp-ping-lag-multipath-05 draft-ietf-mpls-lsp-ping-lag-multipath-06
Abstract Abstract
This document defines extensions to the MPLS Label Switched Path This document defines extensions to the MPLS Label Switched Path
(LSP) Ping and Traceroute mechanisms as specified in RFC 8029. The (LSP) Ping and Traceroute mechanisms as specified in RFC 8029. The
extensions allow the MPLS LSP Ping and Traceroute mechanisms to extensions allow the MPLS LSP Ping and Traceroute mechanisms to
discover and exercise specific paths of Layer 2 (L2) Equal-Cost discover and exercise specific paths of Layer 2 (L2) Equal-Cost
Multipath (ECMP) over Link Aggregation Group (LAG) interfaces. Multipath (ECMP) over Link Aggregation Group (LAG) interfaces.
Additionally, a mechanism is defined to enable determination of the Additionally, a mechanism is defined to enable determination of the
capabilities of an LSR supported. capabilities of an LSR supported.
skipping to change at page 2, line 10 skipping to change at page 2, line 10
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This Internet-Draft will expire on April 26, 2019. This Internet-Draft will expire on September 6, 2019.
Copyright Notice Copyright Notice
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 3 1.2. Background . . . . . . . . . . . . . . . . . . . . . . . 4
2. Overview of Solution . . . . . . . . . . . . . . . . . . . . 4 2. Overview of Solution . . . . . . . . . . . . . . . . . . . . 4
3. LSR Capability Discovery . . . . . . . . . . . . . . . . . . 6 3. LSR Capability Discovery . . . . . . . . . . . . . . . . . . 6
3.1. Initiator LSR Procedures . . . . . . . . . . . . . . . . 7 3.1. Initiator LSR Procedures . . . . . . . . . . . . . . . . 7
3.2. Responder LSR Procedures . . . . . . . . . . . . . . . . 7 3.2. Responder LSR Procedures . . . . . . . . . . . . . . . . 7
4. Mechanism to Discover L2 ECMP Multipath . . . . . . . . . . . 7 4. Mechanism to Discover L2 ECMP Multipath . . . . . . . . . . . 8
4.1. Initiator LSR Procedures . . . . . . . . . . . . . . . . 7 4.1. Initiator LSR Procedures . . . . . . . . . . . . . . . . 8
4.2. Responder LSR Procedures . . . . . . . . . . . . . . . . 8 4.2. Responder LSR Procedures . . . . . . . . . . . . . . . . 8
4.3. Additional Initiator LSR Procedures . . . . . . . . . . . 10 4.3. Additional Initiator LSR Procedures . . . . . . . . . . . 10
5. Mechanism to Validate L2 ECMP Traversal . . . . . . . . . . . 11 5. Mechanism to Validate L2 ECMP Traversal . . . . . . . . . . . 11
5.1. Incoming LAG Member Links Verification . . . . . . . . . 11 5.1. Incoming LAG Member Links Verification . . . . . . . . . 11
5.1.1. Initiator LSR Procedures . . . . . . . . . . . . . . 11 5.1.1. Initiator LSR Procedures . . . . . . . . . . . . . . 11
5.1.2. Responder LSR Procedures . . . . . . . . . . . . . . 12 5.1.2. Responder LSR Procedures . . . . . . . . . . . . . . 12
5.1.3. Additional Initiator LSR Procedures . . . . . . . . . 12 5.1.3. Additional Initiator LSR Procedures . . . . . . . . . 12
5.2. Individual End-to-End Path Verification . . . . . . . . . 13 5.2. Individual End-to-End Path Verification . . . . . . . . . 13
6. LSR Capability TLV . . . . . . . . . . . . . . . . . . . . . 14 6. LSR Capability TLV . . . . . . . . . . . . . . . . . . . . . 14
7. LAG Description Indicator Flag: G . . . . . . . . . . . . . . 15 7. LAG Description Indicator Flag: G . . . . . . . . . . . . . . 15
8. Local Interface Index Sub-TLV . . . . . . . . . . . . . . . . 16 8. Local Interface Index Sub-TLV . . . . . . . . . . . . . . . . 16
9. Remote Interface Index Sub-TLV . . . . . . . . . . . . . . . 17 9. Remote Interface Index Sub-TLV . . . . . . . . . . . . . . . 17
10. Detailed Interface and Label Stack TLV . . . . . . . . . . . 17 10. Detailed Interface and Label Stack TLV . . . . . . . . . . . 17
10.1. Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . . . 19 10.1. Sub-TLVs . . . . . . . . . . . . . . . . . . . . . . . . 19
10.1.1. Incoming Label Stack Sub-TLV . . . . . . . . . . . . 19 10.1.1. Incoming Label Stack Sub-TLV . . . . . . . . . . . . 19
10.1.2. Incoming Interface Index Sub-TLV . . . . . . . . . . 20 10.1.2. Incoming Interface Index Sub-TLV . . . . . . . . . . 20
11. Security Considerations . . . . . . . . . . . . . . . . . . . 21 11. Rate Limiting On Echo Request/Reply Messages . . . . . . . . 21
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21 12. Security Considerations . . . . . . . . . . . . . . . . . . . 21
12.1. LSR Capability TLV . . . . . . . . . . . . . . . . . . . 21 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 21
12.1.1. LSR Capability Flags . . . . . . . . . . . . . . . . 21 13.1. LSR Capability TLV . . . . . . . . . . . . . . . . . . . 21
12.2. Local Interface Index Sub-TLV . . . . . . . . . . . . . 22 13.1.1. LSR Capability Flags . . . . . . . . . . . . . . . . 22
12.2.1. Interface Index Flags . . . . . . . . . . . . . . . 22 13.2. Local Interface Index Sub-TLV . . . . . . . . . . . . . 22
12.3. Remote Interface Index Sub-TLV . . . . . . . . . . . . . 22 13.2.1. Interface Index Flags . . . . . . . . . . . . . . . 22
12.4. Detailed Interface and Label Stack TLV . . . . . . . . . 23 13.3. Remote Interface Index Sub-TLV . . . . . . . . . . . . . 23
12.4.1. Sub-TLVs for TLV Type TBD4 . . . . . . . . . . . . . 23 13.4. Detailed Interface and Label Stack TLV . . . . . . . . . 23
12.5. DS Flags . . . . . . . . . . . . . . . . . . . . . . . . 23 13.4.1. Sub-TLVs for TLV Type TBD4 . . . . . . . . . . . . . 23
13. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 13.5. DS Flags . . . . . . . . . . . . . . . . . . . . . . . . 24
14. References . . . . . . . . . . . . . . . . . . . . . . . . . 24 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24
14.1. Normative References . . . . . . . . . . . . . . . . . . 24 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 24
14.2. Informative References . . . . . . . . . . . . . . . . . 24 15.1. Normative References . . . . . . . . . . . . . . . . . . 24
15.2. Informative References . . . . . . . . . . . . . . . . . 25
Appendix A. LAG with intermediate L2 Switch Issues . . . . . . . 25 Appendix A. LAG with intermediate L2 Switch Issues . . . . . . . 25
A.1. Equal Numbers of LAG Members . . . . . . . . . . . . . . 25 A.1. Equal Numbers of LAG Members . . . . . . . . . . . . . . 25
A.2. Deviating Numbers of LAG Members . . . . . . . . . . . . 25 A.2. Deviating Numbers of LAG Members . . . . . . . . . . . . 26
A.3. LAG Only on Right . . . . . . . . . . . . . . . . . . . . 26 A.3. LAG Only on Right . . . . . . . . . . . . . . . . . . . . 26
A.4. LAG Only on Left . . . . . . . . . . . . . . . . . . . . 26 A.4. LAG Only on Left . . . . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26
1. Introduction 1. Introduction
1.1. Terminology 1.1. Terminology
The following acronyms/terms are used in this document: The following acronyms/terms are used in this document:
o MPLS - Multiprotocol Label Switching. o MPLS - Multiprotocol Label Switching.
o LSP - Label Switched Path. o LSP - Label Switched Path.
o LSR - Label Switching Router. o LSR - Label Switching Router.
o ECMP - Equal-Cost Multipath. o ECMP - Equal-Cost Multipath.
o LAG - Link Aggregation Group. o LAG - Link Aggregation Group.
o Initiator LSR - LSR which sends MPLS echo request. o Initiator LSR - The LSR which sends the MPLS echo request message.
o Responder LSR - LSR which receives MPLS echo request and sends o Responder LSR - The LSR which receives the MPLS echo request
MPLS echo reply. message and sends the MPLS echo reply message.
1.2. Background 1.2. Background
The MPLS Label Switched Path (LSP) Ping and Traceroute mechanisms The MPLS Label Switched Path (LSP) Ping and Traceroute mechanisms
[RFC8029] are powerful tools designed to diagnose all available Layer [RFC8029] are powerful tools designed to diagnose all available Layer
3 (L3) paths of LSPs, including diagnostic coverage of L3 Equal-Cost 3 (L3) paths of LSPs, including diagnostic coverage of L3 Equal-Cost
Multipath (ECMP). In many MPLS networks, Link Aggregation Group Multipath (ECMP). In many MPLS networks, Link Aggregation Group
(LAG) as defined in [IEEE802.1AX], which provides Layer 2 (L2) ECMP, (LAG) as defined in [IEEE802.1AX], which provides Layer 2 (L2) ECMP,
is often used for various reasons. MPLS LSP Ping and Traceroute is often used for various reasons. MPLS LSP Ping and Traceroute
tools were not designed to discover and exercise specific paths of L2 tools were not designed to discover and exercise specific paths of L2
ECMP. This raises a limitation for the following scenario when an ECMP. This raises a limitation for the following scenario when an
LSP traverses over a LAG: LSP traverses over a LAG:
o Label switching over some member links of the LAG is successful, o Label switching over some member links of the LAG is successful,
but will be failed over other member links of the LAG. but will be failed over other member links of the LAG.
o MPLS echo request for the LSP over the LAG is load balanced on one o MPLS echo request for the LSP over the LAG is load balanced on one
of the member links which is label switching successfully. of the member links which is label switching successfully.
With the above scenarios, MPLS LSP Ping and Traceroute will not be With the above scenario, MPLS LSP Ping and Traceroute will not be
able to detect the label switching failure of the problematic member able to detect the label switching failure of the problematic member
link(s) of the LAG. In other words, lack of L2 ECMP diagnostic link(s) of the LAG. In other words, lack of L2 ECMP diagnostic
coverage can produce an outcome where MPLS LSP Ping and Traceroute coverage can produce an outcome where MPLS LSP Ping and Traceroute
can be blind to label switching failures over a problematic LAG can be blind to label switching failures over a problematic LAG
interface. It is, thus, desirable to extend the MPLS LSP Ping and interface. It is, thus, desirable to extend the MPLS LSP Ping and
Traceroute to have deterministic diagnostic coverage of LAG Traceroute to have deterministic diagnostic coverage of LAG
interfaces. interfaces.
The need for a solution of this problem was motivated by issues The need for a solution of this problem was motivated by issues
encountered in live networks. encountered in live networks.
2. Overview of Solution 2. Overview of Solution
This document defines an optional TLV to discover the capabilities of This document defines an optional TLV to discover the capabilities of
a responder LSR and extensions for use with the MPLS LSP Ping and a responder LSR and extensions for use with the MPLS LSP Ping and
Traceroute mechanisms to describe Multipath Information for Traceroute mechanisms to describe Multipath Information for
individual LAG member links, thus allowing MPLS LSP Ping and individual LAG member links, thus allowing MPLS LSP Ping and
Traceroute to discover and exercise specific paths of L2 ECMP over Traceroute to discover and exercise specific paths of L2 ECMP over
LAG interfaces. The reader is expected to be familiar with mechanics LAG interfaces. The reader is expected to be familiar with mechanics
of Downstream Mapping described in Section 3.3 of [RFC8029] and
Downstream Detailed Mapping TLV (DDMAP) described in Section 3.4 of Downstream Detailed Mapping TLV (DDMAP) described in Section 3.4 of
[RFC8029]. [RFC8029].
The solution consists of the MPLS echo request containing a DDMAP TLV The solution consists of the MPLS echo request containing a DDMAP TLV
and the optional LSR capability TLV to indicate that separate load and the optional LSR capability TLV to indicate that separate load
balancing information for each L2 nexthop over LAG is desired in the balancing information for each L2 nexthop over LAG is desired in the
MPLS echo reply. The Responder LSR places the same optional LSR MPLS echo reply. The Responder LSR places the same optional LSR
capability TLV in the MPLS echo reply to provide acknowledgement back capability TLV in the MPLS echo reply to provide acknowledgement back
to the initiator LSR. It also adds, for each downstream LAG member, to the initiator LSR. It also adds, for each downstream LAG member,
load balance information (i.e., multipath information and interface load balance information (i.e., multipath information and interface
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+ The responder LSR MUST add an Multipath Data Sub-TLV for + The responder LSR MUST add an Multipath Data Sub-TLV for
this LAG member link, if the received DDMAP TLV requested this LAG member link, if the received DDMAP TLV requested
multipath information. multipath information.
Based on the procedures described above, every LAG member link will Based on the procedures described above, every LAG member link will
have a Local Interface Index Sub-TLV and a Multipath Data Sub-TLV have a Local Interface Index Sub-TLV and a Multipath Data Sub-TLV
entries in the DDMAP TLV. The order of the Sub-TLVs in the DDMAP TLV entries in the DDMAP TLV. The order of the Sub-TLVs in the DDMAP TLV
for a LAG member link MUST be Local Interface Index Sub-TLV for a LAG member link MUST be Local Interface Index Sub-TLV
immediately followed by Multipath Data Sub-TLV. A LAG member link immediately followed by Multipath Data Sub-TLV. A LAG member link
may also have a corresponding Remote Interface Index Sub-TLV. When a MAY also have a corresponding Remote Interface Index Sub-TLV. When a
Local Interface Index Sub-TLV, a Remote Interface Index-Sub-TLV and a Local Interface Index Sub-TLV, a Remote Interface Index-Sub-TLV and a
Multipath Data Sub-TLV are placed in the DDMAP TLV to describe a LAG Multipath Data Sub-TLV are placed in the DDMAP TLV to describe a LAG
member link, they MUST be placed in the order of Local Interface member link, they MUST be placed in the order of Local Interface
Index Sub-TLV, Remote Interface Index-Sub-TLV and Multipath Data Sub- Index Sub-TLV, Remote Interface Index-Sub-TLV and Multipath Data Sub-
TLV. TLV.
A responder LSR possessing a LAG interface with two member links A responder LSR possessing a LAG interface with two member links
would send the following DDMAP for this LAG interface: would send the following DDMAP for this LAG interface:
0 1 2 3 0 1 2 3
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Multipath Data Sub-TLV LAG member link #1 | | Multipath Data Sub-TLV LAG member link #1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label Stack Sub-TLV | | Label Stack Sub-TLV |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Example of DDMAP in MPLS Echo Request Figure 3: Example of DDMAP in MPLS Echo Request
5. Mechanism to Validate L2 ECMP Traversal 5. Mechanism to Validate L2 ECMP Traversal
Section 4 defines the responder LSR procedures to constructs a DDMAP Section 4 defines the responder LSR procedures to construct a DDMAP
for a downstream LAG. The Remote Interface Index Sub-TLVs that for a downstream LAG. The Remote Interface Index Sub-TLVs that
describes the incoming LAG member links of the downstream LSR is describes the incoming LAG member links of the downstream LSR is
optional, because this information from the downstream LSR is often optional, because this information from the downstream LSR is often
not available on the responder LSR. In such case, the traversal of not available on the responder LSR. In such case, the traversal of
LAG member links can be validated with procedures described in LAG member links can be validated with procedures described in
Section 5.1. If LSRs can provide the Remote Interface Index Sub- Section 5.1. If LSRs can provide the Remote Interface Index Sub-
TLVs, then the validation procedures described in Section 5.2 can be TLVs, then the validation procedures described in Section 5.2 can be
used. used.
5.1. Incoming LAG Member Links Verification 5.1. Incoming LAG Member Links Verification
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o With specific entropy, the interface index of the incoming LAG o With specific entropy, the interface index of the incoming LAG
member link at TTL=n+1. member link at TTL=n+1.
Expectation is that there's a relationship between the interface Expectation is that there's a relationship between the interface
index of the outgoing LAG member link at TTL=n and the interface index of the outgoing LAG member link at TTL=n and the interface
index of the incoming LAG member link at TTL=n+1 for all discovered index of the incoming LAG member link at TTL=n+1 for all discovered
entropies. In other words, set of entropies that load balances to entropies. In other words, set of entropies that load balances to
outgoing LAG member link X at TTL=n should all reach the nexthop on outgoing LAG member link X at TTL=n should all reach the nexthop on
same incoming LAG member link Y at TTL=n+1. same incoming LAG member link Y at TTL=n+1.
With additional logics, the initiator LSR can perform the following With additional logic, the initiator LSR can perform the following
checks in a scenario where the initiator LSR knows that there is a checks in a scenario where the initiator LSR knows that there is a
LAG, with two LAG members, between TTL=n and TTL=n+1, and has the LAG, with two LAG members, between TTL=n and TTL=n+1, and has the
multipath information to traverse the two LAG member links. multipath information to traverse the two LAG member links.
The initiator LSR sends two MPLS echo request messages to traverse The initiator LSR sends two MPLS echo request messages to traverse
the two LAG member links at TTL=n+1: the two LAG member links at TTL=n+1:
o Success case: o Success case:
* One MPLS echo request message reaches TTL=n+1 on an LAG member * One MPLS echo request message reaches TTL=n+1 on an LAG member
skipping to change at page 14, line 50 skipping to change at page 14, line 50
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSR Capability Flags | | LSR Capability Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: LSR Capability TLV Figure 4: LSR Capability TLV
Where: Where:
The Type is 2 octets in length and the value is TBD1. The Type field is 2 octets in length and the value is TBD1.
The Length filed is 2 octets in length, and the value is 4. The Length field is 2 octets in length, and the value is 4.
The LSR Capability Flags is 4 octets in length, this document The "LSR Capability Flags" field is 4 octets in length, this
defines following flags: document defines the following flags:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Must Be Zero (Reserved) |U|D| | Must Be Zero (Reserved) |U|D|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
This document defines two flags. The remaining flags MUST be set This document defines two flags. The remaining flags MUST be set
to zero when sending and ignored on receipt. Both the U and the D to zero when sending and ignored on receipt. Both the U and the D
flag MUST be cleared in the MPLS echo request message when flag MUST be cleared in the MPLS echo request message when
skipping to change at page 15, line 41 skipping to change at page 15, line 41
D Downstream LAG Info Accommodation D Downstream LAG Info Accommodation
An LSR sets this flag when the LSR is capable of An LSR sets this flag when the LSR is capable of
describing LAG member links in the Local Interface describing LAG member links in the Local Interface
Index Sub-TLV and the Multipath Data Sub-TLV in the Index Sub-TLV and the Multipath Data Sub-TLV in the
Downstream Detailed Mapping TLV. Downstream Detailed Mapping TLV.
7. LAG Description Indicator Flag: G 7. LAG Description Indicator Flag: G
This document defines a flag, the "G" flag (LAG Description This document defines a new flag, the "G" flag (LAG Description
Indicator), in the DS Flags field of the DDMAP TLV. Indicator), in the DS Flags field of the DDMAP TLV.
The "G" flag in the MPLS echo request message indicates the request The "G" flag in the MPLS echo request message indicates the request
for detailed LAG information from the responder LSR. In the MPLS for detailed LAG information from the responder LSR. In the MPLS
echo reply message, the "G" flag MUST be set if the DDMAP TLV echo reply message, the "G" flag MUST be set if the DDMAP TLV
describes a LAG interface. It MUST be cleared otherwise. describes a LAG interface. It MUST be cleared otherwise.
The "G" flag is defined as below: The "G" flag is defined as below:
The Bit Number is TBD5. The Bit Number is TBD5.
skipping to change at page 21, line 5 skipping to change at page 21, line 5
M LAG Member Link Indicator M LAG Member Link Indicator
When this flag is set, interface index described in When this flag is set, interface index described in
this sub-TLV is a member of a LAG. this sub-TLV is a member of a LAG.
Incoming Interface Index Incoming Interface Index
An Index assigned by the LSR to this interface. An Index assigned by the LSR to this interface.
11. Security Considerations 11. Rate Limiting On Echo Request/Reply Messages
This document extends LSP Traceroute mechanism to discover and For an LSP path, it may be over several LAGs. Each LAG may have many
exercise L2 ECMP paths. As a result of supporting the code points member links. To exercise all the links, many Echo Request/Reply
and procedures described in this document, additional processing are messages will be sent in a short period. It's possible that those
required by initiator LSRs and responder LSRs, especially to compute messages may traverse a common path as a burst. Under some
and handle the additional multipath information. Due to additional circumstances this might cause congestion at the common path. To
processing, it is critical that proper security measures described in avoid potential congestion, it is RECOMMENDED that implementations to
[RFC8029] are followed. randomly delay the Echo Request and Reply messages at the Initiating
LSRs and Responder LSRs.
The LSP Traceroute allows an initiator LSR to discover the paths of 12. Security Considerations
tested LSPs, providing detailed knowledge of the MPLS network.
Exposing such information to a malicious user is considered
dangerous. To prevent leakage of vital information to untrusted
users, a responder LSR MUST only accept MPLS echo request messages
from trusted sources via filtering source IP address field of
received MPLS echo request messages.[RFC8029] provides additional
recommendations to avoid attacks and recommendations to follow if an
operator desires to prevent tracing.
12. IANA Considerations This document extends LSP Traceroute mechanism [RFC8029] to discover
and exercise L2 ECMP paths to determine problematic member link(s) of
a LAG. These on-demand diagnostic mechanisms are used by an operator
within an MPLS control domain.
12.1. LSR Capability TLV [RFC8029] reviews the possible attacks and approaches to mitigate
possible threats when using these mechanisms.
To prevent leakage of vital information to untrusted users, a
responder LSR MUST only accept MPLS echo request messages from
designated trusted sources via filtering source IP address field of
received MPLS echo request messages. As noted in [RFC8029], spoofing
attacks only have a small window of opportunity. If these messages
are indeed hijacked (non-delivery) by an intermediate node, the use
of these mechanisms will determine the data plane is not working (as
it should). Hijacking of a responder node such that it provides a
legitimate reply would involve compromising the node itself and the
MPLS control domain. [RFC5920] provides additional MPLS network-wide
operation recommendations to avoid attacks and recommendations to
follow.
13. IANA Considerations
13.1. LSR Capability TLV
The IANA is requested to assign new value TBD1 for LSR Capability TLV The IANA is requested to assign new value TBD1 for LSR Capability TLV
from the "Multiprotocol Label Switching Architecture (MPLS) Label from the "Multiprotocol Label Switching Architecture (MPLS) Label
Switched Paths (LSPs) Ping Parameters - TLVs" registry. Switched Paths (LSPs) Ping Parameters - TLVs" registry.
Value Meaning Reference Value Meaning Reference
----- ------- --------- ----- ------- ---------
TBD1 LSR Capability TLV this document TBD1 LSR Capability TLV this document
12.1.1. LSR Capability Flags 13.1.1. LSR Capability Flags
The IANA is requested to create and maintain a registry entitled "LSR The IANA is requested to create and maintain a registry entitled "LSR
Capability Flags" with following registration procedures: Capability Flags" with following registration procedures:
Registry Name: LAG Interface Info Flags Registry Name: LAG Interface Info Flags
Bit number Name Reference Bit number Name Reference
---------- ---------------------------------------- --------- ---------- ---------------------------------------- ---------
31 D: Downstream LAG Info Accommodation this document 31 D: Downstream LAG Info Accommodation this document
30 U: Upstream LAG Info Accommodation this document 30 U: Upstream LAG Info Accommodation this document
0-29 Unassigned 0-29 Unassigned
Assignments of LSR Capability Flags are via Standards Action Assignments of LSR Capability Flags are via Standards Action
[RFC8126]. [RFC8126].
12.2. Local Interface Index Sub-TLV 13.2. Local Interface Index Sub-TLV
The IANA is requested to assign new value TBD2 (from the range The IANA is requested to assign new value TBD2 (from the range
4-31743) for the Local Interface Index Sub-TLV from the 4-31743) for the Local Interface Index Sub-TLV from the
"Multiprotocol Label Switching Architecture (MPLS) Label Switched "Multiprotocol Label Switching Architecture (MPLS) Label Switched
Paths (LSPs) Ping Parameters - TLVs" registry, "Sub-TLVs for TLV Paths (LSPs) Ping Parameters - TLVs" registry, "Sub-TLVs for TLV
Types 20" sub-registry. Types 20" sub-registry.
Value Meaning Reference Value Meaning Reference
----- ------- --------- ----- ------- ---------
TBD2 Local Interface Index Sub-TLV this document TBD2 Local Interface Index Sub-TLV this document
12.2.1. Interface Index Flags 13.2.1. Interface Index Flags
The IANA is requested to create and maintain a registry entitled The IANA is requested to create and maintain a registry entitled
"Interface Index Flags" with following registration procedures: "Interface Index Flags" with following registration procedures:
Registry Name: Interface Index Flags Registry Name: Interface Index Flags
Bit number Name Reference Bit number Name Reference
---------- ---------------------------------------- --------- ---------- ---------------------------------------- ---------
15 M: LAG Member Link Indicator this document 15 M: LAG Member Link Indicator this document
0-14 Unassigned 0-14 Unassigned
skipping to change at page 22, line 44 skipping to change at page 23, line 11
o The Local Interface Index Sub-TLV which may be present in the o The Local Interface Index Sub-TLV which may be present in the
"Downstream Detailed Mapping" TLV. "Downstream Detailed Mapping" TLV.
o The Remote Interface Index Sub-TLV which may be present in the o The Remote Interface Index Sub-TLV which may be present in the
"Downstream Detailed Mapping" TLV. "Downstream Detailed Mapping" TLV.
o The Incoming Interface Index Sub-TLV which may be present in the o The Incoming Interface Index Sub-TLV which may be present in the
"Detailed Interface and Label Stack" TLV. "Detailed Interface and Label Stack" TLV.
12.3. Remote Interface Index Sub-TLV 13.3. Remote Interface Index Sub-TLV
The IANA is requested to assign new value TBD3 (from the range The IANA is requested to assign new value TBD3 (from the range
32768-49161) for the Remote Interface Index Sub-TLV from the 32768-49161) for the Remote Interface Index Sub-TLV from the
"Multiprotocol Label Switching Architecture (MPLS) Label Switched "Multiprotocol Label Switching Architecture (MPLS) Label Switched
Paths (LSPs) Ping Parameters - TLVs" registry, "Sub-TLVs for TLV Paths (LSPs) Ping Parameters - TLVs" registry, "Sub-TLVs for TLV
Types 20" sub-registry. Types 20" sub-registry.
Value Meaning Reference Value Meaning Reference
----- ------- --------- ----- ------- ---------
TBD3 Remote Interface Index Sub-TLV this document TBD3 Remote Interface Index Sub-TLV this document
12.4. Detailed Interface and Label Stack TLV 13.4. Detailed Interface and Label Stack TLV
The IANA is requested to assign new value TBD4 for Detailed Interface The IANA is requested to assign new value TBD4 for Detailed Interface
and Label Stack TLV from the "Multiprotocol Label Switching and Label Stack TLV from the "Multiprotocol Label Switching
Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters - Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters -
TLVs" registry ([IANA-MPLS-LSP-PING]). TLVs" registry ([IANA-MPLS-LSP-PING]).
Value Meaning Reference Value Meaning Reference
----- ------- --------- ----- ------- ---------
TBD4 Detailed Interface and Label Stack TLV this document TBD4 Detailed Interface and Label Stack TLV this document
12.4.1. Sub-TLVs for TLV Type TBD4 13.4.1. Sub-TLVs for TLV Type TBD4
The IANA is requested to create and maintain a sub-registry entitled The IANA is requested to create and maintain a sub-registry entitled
"Sub-TLVs for TLV Type TBD4" under "Multiprotocol Label Switching "Sub-TLVs for TLV Type TBD4" under "Multiprotocol Label Switching
Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters - Architecture (MPLS) Label Switched Paths (LSPs) Ping Parameters -
TLVs" registry. TLVs" registry.
Initial values for this sub-registry, "Sub-TLVs for TLV Types TBD4", Initial values for this sub-registry, "Sub-TLVs for TLV Types TBD4",
are described below. are described below.
Sub-Type Name Reference Sub-Type Name Reference
skipping to change at page 23, line 43 skipping to change at page 24, line 9
2 Incoming Interface Index this document 2 Incoming Interface Index this document
3-16383 Unassigned (mandatory TLVs) 3-16383 Unassigned (mandatory TLVs)
16384-31743 Experimental 16384-31743 Experimental
32768-49161 Unassigned (optional TLVs) 32768-49161 Unassigned (optional TLVs)
49162-64511 Experimental 49162-64511 Experimental
Assignments of Sub-Types in the mandatory and optional spaces are via Assignments of Sub-Types in the mandatory and optional spaces are via
Standards Action [RFC8126]. Assignments of Sub-Types in the Standards Action [RFC8126]. Assignments of Sub-Types in the
experimental space is via Specification Required [RFC8126]. experimental space is via Specification Required [RFC8126].
12.5. DS Flags 13.5. DS Flags
The IANA is requested to assign a new bit number from the "DS flags" The IANA is requested to assign a new bit number from the "DS flags"
sub-registry from the "Multi-Protocol Label Switching (MPLS) Label sub-registry from the "Multi-Protocol Label Switching (MPLS) Label
Switched Paths (LSPs) Ping Parameters - TLVs" registry Switched Paths (LSPs) Ping Parameters - TLVs" registry
([IANA-MPLS-LSP-PING]). ([IANA-MPLS-LSP-PING]).
Note: the "DS flags" sub-registry is created by [RFC8029]. Note: the "DS flags" sub-registry is created by [RFC8029].
Bit number Name Reference Bit number Name Reference
---------- ---------------------------------------- --------- ---------- ---------------------------------------- ---------
TBD5 G: LAG Description Indicator this document TBD5 G: LAG Description Indicator this document
13. Acknowledgements 14. Acknowledgements
The authors would like to thank Nagendra Kumar, Sam Aldrin, for The authors would like to thank Nagendra Kumar, Sam Aldrin, for
providing useful comments and suggestions. The authors would like to providing useful comments and suggestions. The authors would like to
thank Loa Andersson for performing a detailed review and providing thank Loa Andersson for performing a detailed review and providing
number of comments. number of comments.
The authors also would like to extend sincere thanks to the MPLS RT The authors also would like to extend sincere thanks to the MPLS RT
review members who took time to review and provide comments. The review members who took time to review and provide comments. The
members are Eric Osborne, Mach Chen and Yimin Shen. The suggestion members are Eric Osborne, Mach Chen and Yimin Shen. The suggestion
by Mach Chen to generalize and create the LSR Capability TLV was by Mach Chen to generalize and create the LSR Capability TLV was
tremendously helpful for this document and likely for future tremendously helpful for this document and likely for future
documents extending the MPLS LSP Ping and Traceroute mechanism. The documents extending the MPLS LSP Ping and Traceroute mechanism. The
suggestion by Yimin Shen to create two separate validation procedures suggestion by Yimin Shen to create two separate validation procedures
had a big impact to the contents of this document. had a big impact to the contents of this document.
14. References 15. References
14.1. Normative References 15.1. 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>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., [RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N.,
Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Aldrin, S., and M. Chen, "Detecting Multiprotocol Label
Switched (MPLS) Data-Plane Failures", RFC 8029, Switched (MPLS) Data-Plane Failures", RFC 8029,
DOI 10.17487/RFC8029, March 2017, DOI 10.17487/RFC8029, March 2017,
<https://www.rfc-editor.org/info/rfc8029>. <https://www.rfc-editor.org/info/rfc8029>.
[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>.
14.2. Informative References 15.2. Informative References
[IANA-MPLS-LSP-PING] [IANA-MPLS-LSP-PING]
IANA, "Multi-Protocol Label Switching (MPLS) Label IANA, "Multi-Protocol Label Switching (MPLS) Label
Switched Paths (LSPs) Ping Parameters", Switched Paths (LSPs) Ping Parameters",
<http://www.iana.org/assignments/mpls-lsp-ping-parameters/ <http://www.iana.org/assignments/mpls-lsp-ping-parameters/
mpls-lsp-ping-parameters.xhtml>. mpls-lsp-ping-parameters.xhtml>.
[IEEE802.1AX] [IEEE802.1AX]
IEEE Std. 802.1AX, "IEEE Standard for Local and IEEE Std. 802.1AX, "IEEE Standard for Local and
metropolitan area networks - Link Aggregation", November metropolitan area networks - Link Aggregation", November
2008. 2008.
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS
Networks", RFC 5920, DOI 10.17487/RFC5920, July 2010,
<https://www.rfc-editor.org/info/rfc5920>.
[RFC7439] George, W., Ed. and C. Pignataro, Ed., "Gap Analysis for [RFC7439] George, W., Ed. and C. Pignataro, Ed., "Gap Analysis for
Operating IPv6-Only MPLS Networks", RFC 7439, Operating IPv6-Only MPLS Networks", RFC 7439,
DOI 10.17487/RFC7439, January 2015, DOI 10.17487/RFC7439, January 2015,
<https://www.rfc-editor.org/info/rfc7439>. <https://www.rfc-editor.org/info/rfc7439>.
[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>.
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