Extending ICMP for IP-related Information Validation
draft-liu-6man-icmp-verification-02
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| Author | Yao Liu | ||
| Last updated | 2023-02-28 | ||
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draft-liu-6man-icmp-verification-02
6MAN Y. Liu
Internet-Draft ZTE
Intended status: Standards Track 28 February 2023
Expires: 1 September 2023
Extending ICMP for IP-related Information Validation
draft-liu-6man-icmp-verification-02
Abstract
This document introduces the mechanism to verify the data plane
against the control plane in IPv6/SRv6 networks by extending ICMP
messages.
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
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
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 1 September 2023.
Copyright Notice
Copyright (c) 2023 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 carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. ICMPv6 Validation Request . . . . . . . . . . . . . . . . . . 3
2.1. Validation Information Object . . . . . . . . . . . . . . 4
2.1.1. SRv6 Endpoint Behavior . . . . . . . . . . . . . . . 5
2.1.2. IPv6 Prefix IGP Algorithm . . . . . . . . . . . . . . 5
2.1.3. SRv6 IGP-Adjacency Segment . . . . . . . . . . . . . 6
2.1.4. VPN IPv4 Prefix . . . . . . . . . . . . . . . . . . . 8
2.1.5. VPN IPv6 Prefix . . . . . . . . . . . . . . . . . . . 8
3. ICMPv6 Validation Reply . . . . . . . . . . . . . . . . . . . 9
4. ICMP Validation Message Processing . . . . . . . . . . . . . 10
4.1. Sending a Validation Request . . . . . . . . . . . . . . 10
4.2. Receiving a Validation Request . . . . . . . . . . . . . 10
4.3. Sending a Validation Reply . . . . . . . . . . . . . . . 11
4.3.1. Return Code . . . . . . . . . . . . . . . . . . . . . 12
4.4. Receiving a Validation Reply . . . . . . . . . . . . . . 12
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1. Normative References . . . . . . . . . . . . . . . . . . 14
7.2. Informative References . . . . . . . . . . . . . . . . . 15
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 16
1. Introduction
An MPLS label can be related with various FEC information, e.g, VPN
IP prefix [RFC4365], LDP IP prefix[RFC5036], flex algorithms[RFC9350]
and etc. Most of these information can be advertised via control
plane protocols(e.g, IGP, BGP, etc).
Procedures for simple and efficient mechanisms to verify the data
plane against the control plane using LSP Ping in MPLS network are
well defined in [RFC8029]. Normally, when a new feature is
introduced and the MPLS label is associated with new information, the
LSP Ping mechanism is still applicable by defining new FEC sub-TLV
with the new information encoded in it.
On the other hand, IP addresses, especially the IPv6 addresses/SRv6
SIDs, can be related with extra information/functions besides basic
forwarding/routing semantics.
Below is a non-exhaustive list of the information that can be related
with IP addresses/SRv6 SIDs and propagated to the control plane.
* VPN/EVPN Services [RFC9252]
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* SRv6 Endpoint Behaviors for Network Programming [RFC8986]
* Flex Algorithms [RFC9350] [I-D.ietf-lsr-ip-flexalgo]
* Service Functions [I-D.ietf-spring-sr-service-programming]
In IP networks, there're requirements to check the consistency
between the control plane and the data plane to localize faults.
Take IPv4 VPN as an example, in MPLS, an MPLS label is allocated for
the VPN prefix, the label is advertised together with the VPN prefix
via BGP [RFC4365]. To verify this information, VPN IPv4 Prefix FEC
sub-TLV is defined which carries the VPN prefix to be verified via
LSP ping[RFC8029]. Similarly, in SRv6, an SRv6 SID is associated
with a VPN prefix, and they are advertised together via BGP[RFC9252].
One may want to verify the SID-related VPN prefix just like what is
done in MPLS-VPN.
This document introduces the mechanism to verify the data plane
against the control plane in IP networks by extending ICMP messages.
Currently this document focuses on the extensions of ICMPv6 and the
related processing procedures, considering that the requirements are
stronger for IPv6/SRv6 networks.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. ICMPv6 Validation Request
The Validation Request message is defined for ICMPv6[RFC4443]. Like
any ICMPv6 message, the ICMPv6 Validation Request message is
encapsulated in an IPv6 header.
The structure of ICMP Validation Request is shown in Figure 1, where:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |Sequence Number| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ICMP Extension Structure
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Figure 1: Validation Request
* Type: The value is TBD1.
* Code: MUST be set to 0 and MUST be ignored upon receipt.
* Checksum: For ICMPv6, see [RFC4443].
* Identifier: An Identifier to aid in matching Validation Replies to
Validation Requests. May be zero.
* Sequence Number: A Sequence Number to aid in matching Validation
Replies to Validation Requests. May be zero.
* Reserved: This field MUST be set to 0 and ignored upon receipt.
* ICMP Extension Structure: The ICMP Extension Structure carries the
information that needs to be verified. Section 7 of [RFC4884]
defines the ICMP Extension Structure. As per [RFC4884], the
Extension Structure contains one Extension Header followed by one
or more objects. When applied to the ICMP Validation Request
message, the ICMP Extension Structure MUST only contain one or
more instance of the Validation Information Objects as defined in
section 2.1.
2.1. Validation Information Object
The Validation Information Object is shown in Figure 2, where:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Class-Num | C-Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| // (Object payload) // |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Validation Information Object
* Length: Length of the object, measured in octets, including the
Object Header and Object Payload.
* Class-Num: Validation Information Object. The value is TBD2.
* Object payload: Variable-length field. C-Type-specific data.
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* C-Type: For this object, the C-Type is used to indicate the type
of the information that needs to be verified. The values of
C-Type and the corresponding object payload are given below:
C-Type Object Payload
-------- -----------
1 Endpoint Behavior
2 IPv6 Prefix IGP Algorithm
3 SRv6 IGP-Adjacency Segment
4 VPN IPv4 Prefix
5 VPN IPv6 Prefix
Other C-Type values and the corresponding information carried in
object payload will be defined as needed.
2.1.1. SRv6 Endpoint Behavior
When the endpoint behavior[RFC8986] of an SRv6 SID needs to be
verified, the following format of object payload is used.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Endpoint Behavior | Must Be Zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Endpoint Behavior: 2 octets. The codepoints for the Endpoint
behaviors are defined in the "SRv6 Endpoint Behaviors" registry
defined in [RFC8986].
2.1.2. IPv6 Prefix IGP Algorithm
IGP Flex-Algorithm can be used with both Segment Routing data
planes(i.e, SR-MPLS and SRv6) [RFC9350] and for regular IPv4 and IPv6
prefixes [I-D.ietf-lsr-ip-flexalgo] .
When the algorithm of an SRv6 SID or IPv6 prefix needs to be
verified, the following format of object payload is used.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Protocol
Set to 1 if the responder MUST perform validation using OSPF
as the IGP protocol. Set to 2 if the responder MUST perform
validation using IS-IS as the IGP protocol. Set to 0 if the
responder can use any IGP protocol for validation.
Algorithm
Set to 0 if the default algorithm is used. Set to 1 if
Strict Shortest Path First (Strict-SPF) algorithm is used.
For Flex-Algo, the Algorithm field MUST be set with the
algorithm value (values can be 128-255).
SRv6 End SIDs inherit the algorithm from the parent locator.
Reserved
MUST be 0 when originated and MUST be ignored when received.
2.1.3. SRv6 IGP-Adjacency Segment
This object payload is applicable for SRv6 IGP-Adjacency defined in
[RFC8402]. The format is as specified below:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Adj. Type | Protocol | Algorithm | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| Local Interface ID (4 or 16 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| Remote Interface ID (4 or 16 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| Advertising Node Identifier (4 or 6 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ ~
| Receiving Node Identifier (4 or 6 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Adj. Type (Adjacency Type)
Set to 1 when the Adjacency Segment is a Parallel Adjacency
as defined in [RFC8402]. Set to 4 when the Adjacency Segment
is IPv4 based and is not a Parallel Adjacency. Set to 6 when
the Adjacency Segment is IPv6 based and is not a Parallel
Adjacency. Set to 0 when the Adjacency Segment is over an
unnumbered interface.
Protocol
Set to 1 if the responder MUST perform validation using OSPF
as the IGP protocol. Set to 2 if the responder MUST perform
validation using IS-IS as the IGP protocol. Set to 0 if the
responder can use any IGP protocol for validation.
Algorithm
Set to 0 if the default algorithm is used. Set to 1 if
Strict Shortest Path First (Strict-SPF) algorithm is used.
For Flex-Algo, the Algorithm field MUST be set with the
algorithm value (values can be 128-255).
The algorithm is specified in the individual SRv6 Adjacency
SID.
Local Interface ID
An identifier that is assigned by the local node for a link
to which the Adjacency Segment ID is bound. This field is
set to a local link address (IPv4 or IPv6). For IPv4, this
field is 4 octets; for IPv6, this field is 16 octets. If
unnumbered, this field is 4 octets and includes a 32-bit link
identifier as defined in [RFC4203] and [RFC5307]. If the
Adjacency Segment ID represents Parallel Adjacencies, this
field is 4 octets and MUST be set to 4 octets of zeroes.
Remote Interface ID
An identifier that is assigned by the remote node for a link
on which the Adjacency Segment ID is bound. This field is
set to the remote (downstream neighbor) link address (IPv4 or
IPv6). For IPv4, this field is 4 octets; for IPv6, this
field is 16 octets. If unnumbered, this field is 4 octets
and includes a 32-bit link identifier as defined in [RFC4203]
and [RFC5307]. If the Adjacency Segment ID represents
Parallel Adjacencies, this field is 4 octets and MUST be set
to 4 octets of zeroes.
Advertising Node Identifier
This specifies the Advertising Node Identifier. When the
Protocol field is set to 1, then this field is 4 octets and
carries the 32-bit OSPF Router ID. If the Protocol field is
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set to 2, then this field is 6 octets and carries the 48-bit
IS-IS System ID. If the Protocol field is set to 0, then
this field is 4 octets and MUST be set to zero.
Receiving Node Identifier
This specifies the downstream node identifier. When the
Protocol field is set to 1, then this field is 4 octets and
carries the 32-bit OSPF Router ID. If the Protocol field is
set to 2, then this field is 6 octets and carries the 48-bit
IS-IS System ID. If the Protocol field is set to 0, then
this field is 4 octets and MUST be set to zero.
2.1.4. VPN IPv4 Prefix
IPv4 VPN Over SRv6 Core is introduced in [RFC9252], where an SRv6
service SID is associated with a VPN IPv4 prefix at the egress PE.
When the related VPN IPv4 prefix of an SRv6 service SID needs to be
verified, the following format of object payload is used. The Value
field consists of the RD advertised with the VPN IPv4 prefix, the
IPv4 prefix (with trailing 0 bits to make 32 bits in all), and a
prefix length, as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Distinguisher |
| (8 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 prefix |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length | Must Be Zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The RD is an 8-octet identifier, it does not contain any inherent
information. The purpose of the RD is solely to allow one to create
distinct routes to a common IPv4 address prefix. The encoding of the
RD is not important here. When matching this field to the local
information, it is treated as an opaque value.
2.1.5. VPN IPv6 Prefix
IPv6 VPN Over SRv6 Core is introduced in [RFC9252], where an SRv6
service SID is associated with a VPN IPv6 prefix at the egress PE.
When the related VPN IPv6 prefix of an SRv6 service SID needs to be
verified, the following format of object payload is used.
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The object payload field consists of the RD advertised with the VPN
IPv6 prefix, the IPv6 prefix (with trailing 0 bits to make 128 bits
in all), and a prefix length, as follows:
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Route Distinguisher |
| (8 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv6 prefix |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Prefix Length | Must Be Zero |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The RD is an 8-octet identifier, it does not contain any inherent
information. The purpose of the RD is solely to allow one to create
distinct routes to a common IPv4 address prefix. The encoding of the
RD is not important here. When matching this field to the local
information, it is treated as an opaque value.
3. ICMPv6 Validation Reply
The Validation Reply message is defined for ICMPv6. Like any ICMPv6
message, the ICMP Extended Echo Reply message is encapsulated in an
IPv6 header. Figure 3 describes the ICMPv6 Validation Reply message.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identifier |Sequence Number| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Validation Reply
ICMP fields:
* Type: Validation Reply. The value is TBD3.
* Code: Values are
(0) Validation passed
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(1) Malformed request received
(2) One or more of the objects were not understood
(3) Information mismatch
* Checksum: For ICMPv6, see [RFC4443].
* Identifier: Copied from the Identifier field of the invoking
Validation Request packet.
* Sequence Number: Copied from the Sequence Number field of the
invoking Validation Request packet.
4. ICMP Validation Message Processing
4.1. Sending a Validation Request
A node that originates an ICMP validation request message SHOULD
first determine which IP address needs to be verified with what
information. How the sender node get the information is out of scope
of the document.
An ICMPv6 validation request contains one or more Validation
Information objects, depending on how the user wants to do the
validation. For example, an SRv6 service SID is related with an
endpoint behavior and an IPv4 VPN prefix, if one wants to verify both
information of the SID via one request message, an ICMPv6 validation
request is sent with two validation information objects in it. Or
one may choose to send two individual ICMPv6 validation requests,
each carries one validation information object to verify these two
information separately.
The target IP is the IP address/SRv6 SID to be verified and MUST be a
unicast address. The ICMPv6 validation request is sent with the
target IP address/SRv6 SID set as the destination address of the IP
header field without SRH, or set as the last segment with SRH. The
Source Address of the ICMPv6 packet MUST be a unicast address
belonging to the node.
The Hop Limit SHOULD be set to 255 to prevent transit nodes from
processing the validation request.
4.2. Receiving a Validation Request
All transit nodes process the validation request message like any
other IPv6 data packets and hence do not require any change.
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As specified in [RFC4443], if a router receives a packet with a Hop
Limit of zero, or if a router decrements a packet's Hop Limit to
zero, it MUST discard the packet and originate an ICMPv6 Time
Exceeded message with Code 0 to the source of the packet. The source
address SHOULD be set as a local address of the router.
The target node is a node receiving an validation request where the
target IP of that message is locally configured as a segment or local
interface.
When the validation request packet arrives at the target node, and
any of the following conditions apply, the node MUST silently discard
the incoming message:
* The node does not recognize ICMP Validation Request messages.
* The node has not explicitly enabled ICMP Validation functionality.
* The incoming ICMP Validation Request carries a Source Address that
is not explicitly authorized for the incoming ICMP Validation
Request type.
* The Source Address of the incoming message is not a unicast
address.
* The Destination Address of the incoming message is not a unicast
address.
Otherwise, if the packet is well formed, the target node verifies the
information encoded in the Validation Information Object against the
corresponding local information.
4.3. Sending a Validation Reply
When a node receives an ICMPv6 Validation Request, it MUST format an
ICMPv6 Validation Reply as follows:
* Copy the Source Address from the Validation Request message to the
Destination Address of the Validation Reply.
* Copy the Destination Address from the Validation Request message
to the Source Address of the Validation Reply.
* Set the Hop Limit to 255
* Set the Next Header to ICMPv6.
* Set the DiffServ codepoint to CS0 [RFC4594].
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* Set the ICMP Type to Validation Reply.
* Copy the Identifier from the Validation Request message to the
Validation Reply.
* Copy the Sequence Number from the Validation Request message to
the Validation Reply.
* Set the Code field as described in Section 4.3.1
* Set the Checksum appropriately.
* Forward the ICMP Validation Reply to its destination.
4.3.1. Return Code
The Code field MUST be set to 0 if all the the information encoded in
the Validation Information Object is consistent with the the
corresponding local information on the target node.
The Code field MUST be set to 1 if any of the following conditions
apply:
* The ICMP Request does not include an ICMP Extension Structure.
* The ICMP Extension Structure does not only include the Validation
Information Object(s).
* The query is otherwise malformed.
The Code field MUST be set to 2 if one or more of the objects are not
understood by the node.
The Code field MUST be set to 3 if the information in the Validation
Information Object(s) is not consistent with the local information
and validation is not passed.
4.4. Receiving a Validation Reply
A node should only receive a validation reply in response to a
validation request that it sent. Thus, on receipt of a validation
reply, the node should parse the packet to ensure that it is well-
formed, then attempt to match up the validation reply with a
validation request that it had previously sent, using the Identifier
and Sequence Number. If no match is found, the node ignores the echo
reply.
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5. IANA Considerations
This document requests the following actions from IANA:
* Add an entry to the "ICMPv6 "type" Numbers" registry, representing
the Validation Request. This entry has one code 0.
* Add an entry to the "ICMPv6 "type" Numbers" registry, representing
the Validation Reply. This entry has the following codes:
(0) Validation passed
(1) Malformed request received
(2) One or more of the objects were not understood
(3) Information mismatch
* Add an entry to the "Validation Information Object Classes and
Class Sub-types" registry, representing the Validation Information
Object with C-types:
(1) Endpoint Behavior
(2) IPv6 Prefix IGP Algorithm
(3) SRv6 IGP-Adjacency Segment
(4) VPN IPv4 Prefix
(5) VPN IPv6 Prefix
C-Type values are assignable on a first-come-first-serve (FCFS)
basis with a range of 0-255.
All codes mentioned above are assigned on a First Come First Serve
(FCFS) basis with a range of 0-255.
6. Security Considerations
Security considerations discussed in [RFC4443] and[RFC4884] apply to
this document.
To protect against unauthorized sources using validation request
messages to obtain network information, it is RECOMMENDED that
implementations provide a means of checking the source addresses of
validation request messages against an access list before accepting
the message.
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The validation mechanism SHOULD be only used in the limited domain.
The validation request contains the control plane information,
policies should be implemented on the edge devices of the domain to
prevent the information from being leaked into other domains.
In order to protect local resources, implementations SHOULD rate-
limit incoming ICMP Request messages.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005,
<https://www.rfc-editor.org/info/rfc4203>.
[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification", STD 89,
RFC 4443, DOI 10.17487/RFC4443, March 2006,
<https://www.rfc-editor.org/info/rfc4443>.
[RFC4594] Babiarz, J., Chan, K., and F. Baker, "Configuration
Guidelines for DiffServ Service Classes", RFC 4594,
DOI 10.17487/RFC4594, August 2006,
<https://www.rfc-editor.org/info/rfc4594>.
[RFC4884] Bonica, R., Gan, D., Tappan, D., and C. Pignataro,
"Extended ICMP to Support Multi-Part Messages", RFC 4884,
DOI 10.17487/RFC4884, April 2007,
<https://www.rfc-editor.org/info/rfc4884>.
[RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions
in Support of Generalized Multi-Protocol Label Switching
(GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008,
<https://www.rfc-editor.org/info/rfc5307>.
[RFC8402] Filsfils, C., Ed., Previdi, S., Ed., Ginsberg, L.,
Decraene, B., Litkowski, S., and R. Shakir, "Segment
Routing Architecture", RFC 8402, DOI 10.17487/RFC8402,
July 2018, <https://www.rfc-editor.org/info/rfc8402>.
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[RFC8986] Filsfils, C., Ed., Camarillo, P., Ed., Leddy, J., Voyer,
D., Matsushima, S., and Z. Li, "Segment Routing over IPv6
(SRv6) Network Programming", RFC 8986,
DOI 10.17487/RFC8986, February 2021,
<https://www.rfc-editor.org/info/rfc8986>.
7.2. Informative References
[I-D.ietf-lsr-ip-flexalgo]
Britto, W., Hegde, S., Kaneriya, P., Shetty, R., Bonica,
R., and P. Psenak, "IGP Flexible Algorithms (Flex-
Algorithm) In IP Networks", Work in Progress, Internet-
Draft, draft-ietf-lsr-ip-flexalgo-08, 19 December 2022,
<https://datatracker.ietf.org/doc/html/draft-ietf-lsr-ip-
flexalgo-08>.
[I-D.ietf-spring-sr-service-programming]
Clad, F., Xu, X., Filsfils, C., Bernier, D., Li, C.,
Decraene, B., Ma, S., Yadlapalli, C., Henderickx, W., and
S. Salsano, "Service Programming with Segment Routing",
Work in Progress, Internet-Draft, draft-ietf-spring-sr-
service-programming-07, 15 February 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-spring-
sr-service-programming-07>.
[RFC4365] Rosen, E., "Applicability Statement for BGP/MPLS IP
Virtual Private Networks (VPNs)", RFC 4365,
DOI 10.17487/RFC4365, February 2006,
<https://www.rfc-editor.org/info/rfc4365>.
[RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed.,
"LDP Specification", RFC 5036, DOI 10.17487/RFC5036,
October 2007, <https://www.rfc-editor.org/info/rfc5036>.
[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,
<https://www.rfc-editor.org/info/rfc8029>.
[RFC9252] Dawra, G., Ed., Talaulikar, K., Ed., Raszuk, R., Decraene,
B., Zhuang, S., and J. Rabadan, "BGP Overlay Services
Based on Segment Routing over IPv6 (SRv6)", RFC 9252,
DOI 10.17487/RFC9252, July 2022,
<https://www.rfc-editor.org/info/rfc9252>.
Liu Expires 1 September 2023 [Page 15]
Internet-Draft ICMP for Validation February 2023
[RFC9350] Psenak, P., Ed., Hegde, S., Filsfils, C., Talaulikar, K.,
and A. Gulko, "IGP Flexible Algorithm", RFC 9350,
DOI 10.17487/RFC9350, February 2023,
<https://www.rfc-editor.org/info/rfc9350>.
Author's Address
Yao Liu
ZTE
Nanjing
China
Email: liu.yao71@zte.com.cn
Liu Expires 1 September 2023 [Page 16]