draft-ietf-idr-rfc5575bis-19.txt   draft-ietf-idr-rfc5575bis-20.txt 
IDR Working Group C. Loibl IDR Working Group C. Loibl
Internet-Draft Next Layer Communications Internet-Draft Next Layer Communications
Obsoletes: 5575,7674 (if approved) S. Hares Obsoletes: 5575,7674 (if approved) S. Hares
Intended status: Standards Track Huawei Intended status: Standards Track Huawei
Expires: July 20, 2020 R. Raszuk Expires: September 11, 2020 R. Raszuk
Bloomberg LP Bloomberg LP
D. McPherson D. McPherson
Verisign Verisign
M. Bacher M. Bacher
T-Mobile Austria T-Mobile Austria
January 17, 2020 March 10, 2020
Dissemination of Flow Specification Rules Dissemination of Flow Specification Rules
draft-ietf-idr-rfc5575bis-19 draft-ietf-idr-rfc5575bis-20
Abstract Abstract
This document defines a Border Gateway Protocol Network Layer This document defines a Border Gateway Protocol Network Layer
Reachability Information (BGP NLRI) encoding format that can be used Reachability Information (BGP NLRI) encoding format that can be used
to distribute traffic Flow Specifications. This allows the routing to distribute traffic Flow Specifications. This allows the routing
system to propagate information regarding more specific components of system to propagate information regarding more specific components of
the traffic aggregate defined by an IP destination prefix. the traffic aggregate defined by an IP destination prefix.
It also specifies BGP Extended Community encoding formats, that can It also specifies BGP Extended Community encoding formats, that can
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 20, 2020. This Internet-Draft will expire on September 11, 2020.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Definitions of Terms Used in This Memo . . . . . . . . . . . 5 2. Definitions of Terms Used in This Memo . . . . . . . . . . . 5
3. Flow Specifications . . . . . . . . . . . . . . . . . . . . . 5 3. Flow Specifications . . . . . . . . . . . . . . . . . . . . . 5
4. Dissemination of IPv4 Flow Specification Information . . . . 6 4. Dissemination of IPv4 Flow Specification Information . . . . 6
4.1. Length Encoding . . . . . . . . . . . . . . . . . . . . . 7 4.1. Length Encoding . . . . . . . . . . . . . . . . . . . . . 6
4.2. NLRI Value Encoding . . . . . . . . . . . . . . . . . . . 7 4.2. NLRI Value Encoding . . . . . . . . . . . . . . . . . . . 7
4.2.1. Operators . . . . . . . . . . . . . . . . . . . . . . 8 4.2.1. Operators . . . . . . . . . . . . . . . . . . . . . . 7
4.2.2. Components . . . . . . . . . . . . . . . . . . . . . 9 4.2.2. Components . . . . . . . . . . . . . . . . . . . . . 9
4.3. Examples of Encodings . . . . . . . . . . . . . . . . . . 14 4.3. Examples of Encodings . . . . . . . . . . . . . . . . . . 13
5. Traffic Filtering . . . . . . . . . . . . . . . . . . . . . . 16 5. Traffic Filtering . . . . . . . . . . . . . . . . . . . . . . 16
5.1. Ordering of Flow Specifications . . . . . . . . . . . . . 17 5.1. Ordering of Flow Specifications . . . . . . . . . . . . . 17
6. Validation Procedure . . . . . . . . . . . . . . . . . . . . 18 6. Validation Procedure . . . . . . . . . . . . . . . . . . . . 18
7. Traffic Filtering Actions . . . . . . . . . . . . . . . . . . 19 7. Traffic Filtering Actions . . . . . . . . . . . . . . . . . . 19
7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 20 7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 20
7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type 7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type
TBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 TBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.3. Traffic-action (traffic-action) sub-type 0x07 . . . . . . 21 7.3. Traffic-action (traffic-action) sub-type 0x07 . . . . . . 21
7.4. RT Redirect (rt-redirect) sub-type 0x08 . . . . . . . . . 22 7.4. RT Redirect (rt-redirect) sub-type 0x08 . . . . . . . . . 22
7.5. Traffic Marking (traffic-marking) sub-type 0x09 . . . . . 22 7.5. Traffic Marking (traffic-marking) sub-type 0x09 . . . . . 22
7.6. Interaction with other Filtering Mechanisms in Routers . 23 7.6. Interaction with other Filtering Mechanisms in Routers . 23
7.7. Considerations on Traffic Filtering Action Interference . 23 7.7. Considerations on Traffic Filtering Action Interference . 23
8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks . 24 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks . 24
9. Traffic Monitoring . . . . . . . . . . . . . . . . . . . . . 25 9. Traffic Monitoring . . . . . . . . . . . . . . . . . . . . . 25
10. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 25 10. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 25
11. Future NLRI Extensions . . . . . . . . . . . . . . . . . . . 25 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 26 11.1. AFI/SAFI Definitions . . . . . . . . . . . . . . . . . . 25
12.1. AFI/SAFI Definitions . . . . . . . . . . . . . . . . . . 26 11.2. Flow Component Definitions . . . . . . . . . . . . . . . 26
12.2. Flow Component Definitions . . . . . . . . . . . . . . . 26 11.3. Extended Community Flow Specification Actions . . . . . 27
12.3. Extended Community Flow Specification Actions . . . . . 27 12. Security Considerations . . . . . . . . . . . . . . . . . . . 29
13. Security Considerations . . . . . . . . . . . . . . . . . . . 30 13. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 31
14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 32 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 31
15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 32 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 31
16. References . . . . . . . . . . . . . . . . . . . . . . . . . 32 15.1. Normative References . . . . . . . . . . . . . . . . . . 31
16.1. Normative References . . . . . . . . . . . . . . . . . . 32 15.2. Informative References . . . . . . . . . . . . . . . . . 33
16.2. Informative References . . . . . . . . . . . . . . . . . 34 15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 34
16.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Appendix A. Python code: flow_rule_cmp . . . . . . . . . . . . . 34
Appendix A. Python code: flow_rule_cmp . . . . . . . . . . . . . 35 Appendix B. Comparison with RFC 5575 . . . . . . . . . . . . . . 35
Appendix B. Comparison with RFC 5575 . . . . . . . . . . . . . . 36 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 36
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 37
1. Introduction 1. Introduction
This document obsoletes both This document obsoletes both
"Dissemination of Flow Specification Rules" [RFC5575] and "Dissemination of Flow Specification Rules" [RFC5575] and
"Clarification of the Flowspec Redirect Extended Community"[RFC7674]. "Clarification of the Flowspec Redirect Extended Community"[RFC7674].
Modern IP routers contain both the capability to forward traffic Modern IP routers contain both the capability to forward traffic
according to IP prefixes as well as to classify, shape, rate limit, according to IP prefixes as well as to classify, shape, rate limit,
filter, or redirect packets based on administratively defined filter, or redirect packets based on administratively defined
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While it is certainly possible to address this problem using other While it is certainly possible to address this problem using other
mechanisms, this solution has been utilized in deployments because of mechanisms, this solution has been utilized in deployments because of
the substantial advantage of being an incremental addition to already the substantial advantage of being an incremental addition to already
deployed mechanisms. deployed mechanisms.
In current deployments, the information distributed by this extension In current deployments, the information distributed by this extension
is originated both manually as well as automatically. The latter by is originated both manually as well as automatically. The latter by
systems that are able to detect malicious traffic flows. When systems that are able to detect malicious traffic flows. When
automated systems are used, care should be taken to ensure their automated systems are used, care should be taken to ensure their
correctness as well as the limitations of the systems that receive correctness as well as the limitations of the systems that receive
and process the advertised Flow Specifications (see also Section 13). and process the advertised Flow Specifications (see also Section 12).
This specification defines required protocol extensions to address This specification defines required protocol extensions to address
most common applications of IPv4 unicast and VPNv4 unicast filtering. most common applications of IPv4 unicast and VPNv4 unicast filtering.
The same mechanism can be reused and new match criteria added to The same mechanism can be reused and new match criteria added to
address similar filtering needs for other BGP address families such address similar filtering needs for other BGP address families such
as IPv6 families [I-D.ietf-idr-flow-spec-v6]. as IPv6 families [I-D.ietf-idr-flow-spec-v6].
2. Definitions of Terms Used in This Memo 2. Definitions of Terms Used in This Memo
AFI - Address Family Identifier. AFI - Address Family Identifier.
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Figure 1: Flow Specification NLRI for IPv4 Figure 1: Flow Specification NLRI for IPv4
Implementations wishing to exchange Flow Specification MUST use BGP's Implementations wishing to exchange Flow Specification MUST use BGP's
Capability Advertisement facility to exchange the Multiprotocol Capability Advertisement facility to exchange the Multiprotocol
Extension Capability Code (Code 1) as defined in [RFC4760]. The Extension Capability Code (Code 1) as defined in [RFC4760]. The
(AFI, SAFI) pair carried in the Multiprotocol Extension Capability (AFI, SAFI) pair carried in the Multiprotocol Extension Capability
MUST be (AFI=1, SAFI=133) for IPv4 Flow Specification, and (AFI=1, MUST be (AFI=1, SAFI=133) for IPv4 Flow Specification, and (AFI=1,
SAFI=134) for VPNv4 Flow Specification. SAFI=134) for VPNv4 Flow Specification.
The Flow Specification NLRI is considered a Typed NLRI in the sense
of Section 5.4 of [RFC7606]. See also Section 4.2 on unknown
component type handling.
4.1. Length Encoding 4.1. Length Encoding
o If the NLRI length is smaller than 240 (0xf0 hex) octets, the o If the NLRI length is smaller than 240 (0xf0 hex) octets, the
length field can be encoded as a single octet. length field can be encoded as a single octet.
o Otherwise, it is encoded as an extended-length 2-octet value in o Otherwise, it is encoded as an extended-length 2-octet value in
which the most significant nibble of the first byte is all ones. which the most significant nibble of the first octet is all ones.
In Figure 1 above, values less-than 240 are encoded using two hex In Figure 1 above, values less-than 240 are encoded using two hex
digits (0xnn). Values above 239 are encoded using 3 hex digits digits (0xnn). Values above 239 are encoded using 3 hex digits
(0xfnnn). The highest value that can be represented with this (0xfnnn). The highest value that can be represented with this
encoding is 4095. For example the length value of 239 is encoded as encoding is 4095. For example the length value of 239 is encoded as
0xef (single octet) while 240 is encoded as 0xf0f0 (2-octet). 0xef (single octet) while 240 is encoded as 0xf0f0 (2-octet).
4.2. NLRI Value Encoding 4.2. NLRI Value Encoding
The Flow Specification NLRI value consists of a list of optional The Flow Specification NLRI value consists of a list of optional
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Components MUST follow strict type ordering by increasing numerical Components MUST follow strict type ordering by increasing numerical
order. A given component type may (exactly once) or may not be order. A given component type may (exactly once) or may not be
present in the Flow Specification. If present, it MUST precede any present in the Flow Specification. If present, it MUST precede any
component of higher numeric type value. component of higher numeric type value.
All combinations of components within a single Flow Specification are All combinations of components within a single Flow Specification are
allowed. However, some combinations cannot match any packets (e.g. allowed. However, some combinations cannot match any packets (e.g.
"ICMP Type AND Port" will never match any packets), and thus SHOULD "ICMP Type AND Port" will never match any packets), and thus SHOULD
NOT be propagated by BGP. NOT be propagated by BGP.
An advertisement containing an unknown Flow Specification component A NLRI value not encoded as specified in Section 4.2 is considered
type should be discarded as specified in Section 5.4 of [RFC7606]. malformed and error handling according to Section 10 is performed.
It needs to be pointed out that the encoding of the NLRI as a 2-tuple
<length, NLRI value> allows to skip over a NLRI value (the NLRI that
value should be discarded).
Except for an unknown component type (see above), a NLRI value not
encoded as specified in Section 4.2 is considered malformed and error
handling according to Section 10 is performed.
4.2.1. Operators 4.2.1. Operators
Most of the components described below make use of comparison Most of the components described below make use of comparison
operators. Which of the two operators is used is defined by the operators. Which of the two operators is used is defined by the
components in Section 4.2.2. The operators are encoded as a single components in Section 4.2.2. The operators are encoded as a single
octet. octet.
4.2.1.1. Numeric Operator (numeric_op) 4.2.1.1. Numeric Operator (numeric_op)
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+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| e | a | len | 0 |lt |gt |eq | | e | a | len | 0 |lt |gt |eq |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 2: Numeric Operator (numeric_op) Figure 2: Numeric Operator (numeric_op)
e - end-of-list bit: Set in the last {op, value} pair in the list. e - end-of-list bit: Set in the last {op, value} pair in the list.
a - AND bit: If unset, the previous term is logically ORed with the a - AND bit: If unset, the previous term is logically ORed with the
current one. If set, the operation is a logical AND. In the current one. If set, the operation is a logical AND. In the
first operator byte of a sequence it SHOULD be encoded as unset first operator octet of a sequence it SHOULD be encoded as unset
and and MUST be treated as always unset on decoding. The AND and and MUST be treated as always unset on decoding. The AND
operator has higher priority than OR for the purposes of operator has higher priority than OR for the purposes of
evaluating logical expressions. evaluating logical expressions.
len - length: The length of the value field for this operator given len - length: The length of the value field for this operator given
as (1 << len). This encodes 1 (len=00), 2 (len=01), 4 (len=10), 8 as (1 << len). This encodes 1 (len=00), 2 (len=01), 4 (len=10), 8
(len=11) bytes. (len=11) octets.
0 - SHOULD be set to 0 on NLRI encoding, and MUST be ignored during 0 - SHOULD be set to 0 on NLRI encoding, and MUST be ignored during
decoding decoding
lt - less than comparison between data and value. lt - less than comparison between data and value.
gt - greater than comparison between data and value. gt - greater than comparison between data and value.
eq - equality between data and value. eq - equality between data and value.
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Encoding: <type (1 octet), length (1 octet), prefix (variable)> Encoding: <type (1 octet), length (1 octet), prefix (variable)>
Defines the source prefix to match. The length and prefix fields are Defines the source prefix to match. The length and prefix fields are
encoded as in BGP UPDATE messages [RFC4271] encoded as in BGP UPDATE messages [RFC4271]
4.2.2.3. Type 3 - IP Protocol 4.2.2.3. Type 3 - IP Protocol
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Contains a list of {numeric_op, value} pairs that are used to match Contains a list of {numeric_op, value} pairs that are used to match
the IP protocol value byte in IP packet header (see [RFC0791] the IP protocol value octet in IP packet header (see [RFC0791]
Section 3.1). Section 3.1).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 3 component values SHOULD be encoded as single Section 4.2.1.1. Type 3 component values SHOULD be encoded as single
byte (numeric_op len=00). octet (numeric_op len=00).
4.2.2.4. Type 4 - Port 4.2.2.4. Type 4 - Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs that matches source OR Defines a list of {numeric_op, value} pairs that matches source OR
destination TCP/UDP ports (see [RFC0793] Section 3.1 and [RFC0768] destination TCP/UDP ports (see [RFC0793] Section 3.1 and [RFC0768]
Section "Format"). This component matches if either the destination Section "Format"). This component matches if either the destination
port OR the source port of a IP packet matches the value. port OR the source port of a IP packet matches the value.
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 4 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 4 component values SHOULD be encoded as 1- or
2-byte quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
In case of the presence of the port (destination-port, source-port) In case of the presence of the port (destination-port, source-port)
component only TCP or UDP packets can match the entire Flow component only TCP or UDP packets can match the entire Flow
Specification. The port component, if present, never matches when Specification. The port component, if present, never matches when
the packet's IP protocol value is not 6 (TCP) or 17 (UDP), if the the packet's IP protocol value is not 6 (TCP) or 17 (UDP), if the
packet is fragmented and this is not the first fragment, or if the packet is fragmented and this is not the first fragment, or if the
system is unable to locate the transport header. Different system is unable to locate the transport header. Different
implementations may or may not be able to decode the transport header implementations may or may not be able to decode the transport header
in the presence of IP options or Encapsulating Security Payload (ESP) in the presence of IP options or Encapsulating Security Payload (ESP)
NULL [RFC4303] encryption. NULL [RFC4303] encryption.
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4.2.2.5. Type 5 - Destination Port 4.2.2.5. Type 5 - Destination Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the Defines a list of {numeric_op, value} pairs used to match the
destination port of a TCP or UDP packet (see also [RFC0793] destination port of a TCP or UDP packet (see also [RFC0793]
Section 3.1 and [RFC0768] Section "Format"). Section 3.1 and [RFC0768] Section "Format").
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 5 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 5 component values SHOULD be encoded as 1- or
2-byte quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
The last paragraph of Section 4.2.2.4 also applies to this component. The last paragraph of Section 4.2.2.4 also applies to this component.
4.2.2.6. Type 6 - Source Port 4.2.2.6. Type 6 - Source Port
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the source Defines a list of {numeric_op, value} pairs used to match the source
port of a TCP or UDP packet (see also [RFC0793] Section 3.1 and port of a TCP or UDP packet (see also [RFC0793] Section 3.1 and
[RFC0768] Section "Format"). [RFC0768] Section "Format").
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 6 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 6 component values SHOULD be encoded as 1- or
2-byte quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
The last paragraph of Section 4.2.2.4 also applies to this component. The last paragraph of Section 4.2.2.4 also applies to this component.
4.2.2.7. Type 7 - ICMP type 4.2.2.7. Type 7 - ICMP type
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the type Defines a list of {numeric_op, value} pairs used to match the type
field of an ICMP packet (see also [RFC0792] Section "Message field of an ICMP packet (see also [RFC0792] Section "Message
Formats"). Formats").
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 7 component values SHOULD be encoded as single Section 4.2.1.1. Type 7 component values SHOULD be encoded as single
byte (numeric_op len=00). octet (numeric_op len=00).
In case of the presence of the ICMP type (code) component only ICMP In case of the presence of the ICMP type (code) component only ICMP
packets can match the entire Flow Specification. The ICMP type packets can match the entire Flow Specification. The ICMP type
(code) component, if present, never matches when the packet's IP (code) component, if present, never matches when the packet's IP
protocol value is not 1 (ICMP), if the packet is fragmented and this protocol value is not 1 (ICMP), if the packet is fragmented and this
is not the first fragment, or if the system is unable to locate the is not the first fragment, or if the system is unable to locate the
transport header. Different implementations may or may not be able transport header. Different implementations may or may not be able
to decode the transport header in the presence of IP options or to decode the transport header in the presence of IP options or
Encapsulating Security Payload (ESP) NULL [RFC4303] encryption. Encapsulating Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.8. Type 8 - ICMP code 4.2.2.8. Type 8 - ICMP code
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the code Defines a list of {numeric_op, value} pairs used to match the code
field of an ICMP packet (see also [RFC0792] Section "Message field of an ICMP packet (see also [RFC0792] Section "Message
Formats"). Formats").
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 8 component values SHOULD be encoded as single Section 4.2.1.1. Type 8 component values SHOULD be encoded as single
byte (numeric_op len=00). octet (numeric_op len=00).
The last paragraph of Section 4.2.2.7 also applies to this component. The last paragraph of Section 4.2.2.7 also applies to this component.
4.2.2.9. Type 9 - TCP flags 4.2.2.9. Type 9 - TCP flags
Encoding: <type (1 octet), [bitmask_op, bitmask]+> Encoding: <type (1 octet), [bitmask_op, bitmask]+>
Defines a list of {bitmask_op, bitmask} pairs used to match TCP Defines a list of {bitmask_op, bitmask} pairs used to match TCP
Control Bits (see also [RFC0793] Section 3.1). Control Bits (see also [RFC0793] Section 3.1).
This component uses the Bitmask Operator (bitmask_op) described in This component uses the Bitmask Operator (bitmask_op) described in
Section 4.2.1.2. Type 9 component bitmasks MUST be encoded as 1- or Section 4.2.1.2. Type 9 component bitmasks MUST be encoded as 1- or
2-byte bitmask (bitmask_op len=00 or len=01). 2-octet bitmask (bitmask_op len=00 or len=01).
When a single byte (bitmask_op len=00) is specified, it matches byte When a single octet (bitmask_op len=00) is specified, it matches
14 of the TCP header (see also [RFC0793] Section 3.1), which contains octet 14 of the TCP header (see also [RFC0793] Section 3.1), which
the TCP Control Bits. When a 2-byte (bitmask_op len=01) encoding is contains the TCP Control Bits. When a 2-octet (bitmask_op len=01)
used, it matches bytes 13 and 14 of the TCP header with the data encoding is used, it matches octets 13 and 14 of the TCP header with
offset (leftmost 4 bits) always treated as 0. the data offset (leftmost 4 bits) always treated as 0.
In case of the presence of the TCP flags component only TCP packets In case of the presence of the TCP flags component only TCP packets
can match the entire Flow Specification. The TCP flags component, if can match the entire Flow Specification. The TCP flags component, if
present, never matches when the packet's IP protocol value is not 6 present, never matches when the packet's IP protocol value is not 6
(TCP), if the packet is fragmented and this is not the first (TCP), if the packet is fragmented and this is not the first
fragment, or if the system is unable to locate the transport header. fragment, or if the system is unable to locate the transport header.
Different implementations may or may not be able to decode the Different implementations may or may not be able to decode the
transport header in the presence of IP options or Encapsulating transport header in the presence of IP options or Encapsulating
Security Payload (ESP) NULL [RFC4303] encryption. Security Payload (ESP) NULL [RFC4303] encryption.
4.2.2.10. Type 10 - Packet length 4.2.2.10. Type 10 - Packet length
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match on the Defines a list of {numeric_op, value} pairs used to match on the
total IP packet length (excluding Layer 2 but including IP header). total IP packet length (excluding Layer 2 but including IP header).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 10 component values SHOULD be encoded as 1- or Section 4.2.1.1. Type 10 component values SHOULD be encoded as 1- or
2-byte quantities (numeric_op len=00 or len=01). 2-octet quantities (numeric_op len=00 or len=01).
4.2.2.11. Type 11 - DSCP (Diffserv Code Point) 4.2.2.11. Type 11 - DSCP (Diffserv Code Point)
Encoding: <type (1 octet), [numeric_op, value]+> Encoding: <type (1 octet), [numeric_op, value]+>
Defines a list of {numeric_op, value} pairs used to match the 6-bit Defines a list of {numeric_op, value} pairs used to match the 6-bit
DSCP field (see also [RFC2474]). DSCP field (see also [RFC2474]).
This component uses the Numeric Operator (numeric_op) described in This component uses the Numeric Operator (numeric_op) described in
Section 4.2.1.1. Type 11 component values MUST be encoded as single Section 4.2.1.1. Type 11 component values MUST be encoded as single
byte (numeric_op len=00). octet (numeric_op len=00).
The six least significant bits contain the DSCP value. All other The six least significant bits contain the DSCP value. All other
bits SHOULD be treated as 0. bits SHOULD be treated as 0.
4.2.2.12. Type 12 - Fragment 4.2.2.12. Type 12 - Fragment
Encoding: <type (1 octet), [bitmask_op, bitmask]+> Encoding: <type (1 octet), [bitmask_op, bitmask]+>
Defines a list of {bitmask_op, bitmask} pairs used to match specific Defines a list of {bitmask_op, bitmask} pairs used to match specific
IP fragments. IP fragments.
This component uses the Bitmask Operator (bitmask_op) described in This component uses the Bitmask Operator (bitmask_op) described in
Section 4.2.1.2. The Type 12 component bitmask MUST be encoded as Section 4.2.1.2. The Type 12 component bitmask MUST be encoded as
single byte bitmask (bitmask_op len=00). single octet bitmask (bitmask_op len=00).
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
| 0 | 0 | 0 | 0 |LF |FF |IsF|DF | | 0 | 0 | 0 | 0 |LF |FF |IsF|DF |
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
Figure 4: Fragment Bitmask Operand Figure 4: Fragment Bitmask Operand
Bitmask values: Bitmask values:
skipping to change at page 20, line 7 skipping to change at page 20, line 7
The default action for a matching Flow Specification is to accept the The default action for a matching Flow Specification is to accept the
packet (treat the packet according to the normal forwarding behaviour packet (treat the packet according to the normal forwarding behaviour
of the system). of the system).
This document defines the following extended communities values shown This document defines the following extended communities values shown
in Table 2 in the form 0xttss where tt indicates the type and ss in Table 2 in the form 0xttss where tt indicates the type and ss
indicates the sub-type of the extended community. Encodings for indicates the sub-type of the extended community. Encodings for
these extended communities are described below. these extended communities are described below.
+--------------+--------------------------+-------------------------+ +-------------+---------------------------+-------------------------+
| community | action | encoding | | community | action | encoding |
| 0xttss | | | | 0xttss | | |
+--------------+--------------------------+-------------------------+ +-------------+---------------------------+-------------------------+
| 0x8006 | traffic-rate-bytes | 2-byte ASN, 4-byte | | 0x8006 | traffic-rate-bytes | 2-octet ASN, 4-octet |
| | (Section 7.1) | float | | | (Section 7.1) | float |
| TBD | traffic-rate-packets | 2-byte ASN, 4-byte | | TBD | traffic-rate-packets | 2-octet ASN, 4-octet |
| | (Section 7.1) | float | | | (Section 7.1) | float |
| 0x8007 | traffic-action (Section | bitmask | | 0x8007 | traffic-action | bitmask |
| | 7.3) | | | | (Section 7.3) | |
| 0x8008 | rt-redirect AS-2byte | 2-octet AS, 4-octet | | 0x8008 | rt-redirect AS-2octet | 2-octet AS, 4-octet |
| | (Section 7.4) | value | | | (Section 7.4) | value |
| 0x8108 | rt-redirect IPv4 | 4-octet IPv4 address, | | 0x8108 | rt-redirect IPv4 | 4-octet IPv4 address, |
| | (Section 7.4) | 2-octet value | | | (Section 7.4) | 2-octet value |
| 0x8208 | rt-redirect AS-4byte | 4-octet AS, 2-octet | | 0x8208 | rt-redirect AS-4octet | 4-octet AS, 2-octet |
| | (Section 7.4) | value | | | (Section 7.4) | value |
| 0x8009 | traffic-marking (Section | DSCP value | | 0x8009 | traffic-marking | DSCP value |
| | 7.5) | | | | (Section 7.5) | |
+--------------+--------------------------+-------------------------+ +-------------+---------------------------+-------------------------+
Table 2: Traffic Filtering Action Extended Communities Table 2: Traffic Filtering Action Extended Communities
Multiple Traffic Filtering Actions defined in this document may be Multiple Traffic Filtering Actions defined in this document may be
present for a single Flow Specification and SHOULD be applied to the present for a single Flow Specification and SHOULD be applied to the
traffic flow (for example traffic-rate-bytes and rt-redirect can be traffic flow (for example traffic-rate-bytes and rt-redirect can be
applied to packets at the same time). If not all of the Traffic applied to packets at the same time). If not all of the Traffic
Filtering Actions can be applied to a traffic flow they should be Filtering Actions can be applied to a traffic flow they should be
treated as interfering Traffic filtering actions (see below). treated as interfering Traffic filtering actions (see below).
skipping to change at page 21, line 6 skipping to change at page 21, line 6
All Traffic Filtering Actions are specified as transitive BGP All Traffic Filtering Actions are specified as transitive BGP
Extended Communities. Extended Communities.
7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06
The traffic-rate-bytes extended community uses the following extended The traffic-rate-bytes extended community uses the following extended
community encoding: community encoding:
The first two octets carry the 2-octet id, which can be assigned from The first two octets carry the 2-octet id, which can be assigned from
a 2-byte AS number. When a 4-byte AS number is locally present, the a 2-octet AS number. When a 4-octet AS number is locally present,
2 least significant bytes of such an AS number can be used. This the 2 least significant octets of such an AS number can be used.
value is purely informational and SHOULD NOT be interpreted by the This value is purely informational and SHOULD NOT be interpreted by
implementation. the implementation.
The remaining 4 octets carry the maximum rate information in IEEE The remaining 4 octets carry the maximum rate information in IEEE
floating point [IEEE.754.1985] format, units being bytes per second. floating point [IEEE.754.1985] format, units being bytes per second.
A traffic-rate of 0 should result on all traffic for the particular A traffic-rate of 0 should result on all traffic for the particular
flow to be discarded. On encoding the traffic-rate MUST NOT be flow to be discarded. On encoding the traffic-rate MUST NOT be
negative. On decoding negative values MUST be treated as zero negative. On decoding negative values MUST be treated as zero
(discard all traffic). (discard all traffic).
Interferes with: No other BGP Flow Specification Traffic Filtering Interferes with: No other BGP Flow Specification Traffic Filtering
Action in this document. Action in this document.
skipping to change at page 21, line 36 skipping to change at page 21, line 36
rate-packets of 0 should result in all traffic for the particular rate-packets of 0 should result in all traffic for the particular
flow to be discarded. On encoding the traffic-rate-packets MUST NOT flow to be discarded. On encoding the traffic-rate-packets MUST NOT
be negative. On decoding negative values MUST be treated as zero be negative. On decoding negative values MUST be treated as zero
(discard all traffic). (discard all traffic).
Interferes with: No other BGP Flow Specification Traffic Filtering Interferes with: No other BGP Flow Specification Traffic Filtering
Action in this document. Action in this document.
7.3. Traffic-action (traffic-action) sub-type 0x07 7.3. Traffic-action (traffic-action) sub-type 0x07
The traffic-action extended community consists of 6 bytes of which The traffic-action extended community consists of 6 octets of which
only the 2 least significant bits of the 6th byte (from left to only the 2 least significant bits of the 6th octet (from left to
right) are defined by this document as shown in Figure 5. right) are defined by this document as shown in Figure 5.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Traffic Action Field | | Traffic Action Field |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tr. Action Field (cont.) |S|T| | Tr. Action Field (cont.) |S|T|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 22, line 14 skipping to change at page 22, line 14
o T: Terminal Action (bit 47): When this bit is set, the traffic o T: Terminal Action (bit 47): When this bit is set, the traffic
filtering engine will evaluate any subsequent Flow Specifications filtering engine will evaluate any subsequent Flow Specifications
(as defined by the ordering procedure Section 5.1). If not set, (as defined by the ordering procedure Section 5.1). If not set,
the evaluation of the traffic filters stops when this Flow the evaluation of the traffic filters stops when this Flow
Specification is evaluated. Specification is evaluated.
o S: Sample (bit 46): Enables traffic sampling and logging for this o S: Sample (bit 46): Enables traffic sampling and logging for this
Flow Specification (only effective when set). Flow Specification (only effective when set).
o Traffic Action Field: Other Traffic Action Field (see Section 12) o Traffic Action Field: Other Traffic Action Field (see Section 11)
bits unused in this specification. These bits SHOULD be set to 0 bits unused in this specification. These bits SHOULD be set to 0
on encoding, and MUST be ignored during decoding. on encoding, and MUST be ignored during decoding.
The use of the Terminal Action (bit 47) may result in more than one The use of the Terminal Action (bit 47) may result in more than one
Flow Specification matching a particular traffic flow. All the Flow Specification matching a particular traffic flow. All the
Traffic Filtering Actions from these Flow Specifications shall be Traffic Filtering Actions from these Flow Specifications shall be
collected and applied. In case of interfering Traffic Filtering collected and applied. In case of interfering Traffic Filtering
Actions it is an implementation decision which Traffic Filtering Actions it is an implementation decision which Traffic Filtering
Actions are selected. See also Section 7.7. Actions are selected. See also Section 7.7.
skipping to change at page 24, line 10 skipping to change at page 24, line 10
If a Flow Specification associated with interfering Traffic Filtering If a Flow Specification associated with interfering Traffic Filtering
Actions is selected for packet forwarding, it is an implementation Actions is selected for packet forwarding, it is an implementation
decision which of the interfering Traffic Filtering Actions are decision which of the interfering Traffic Filtering Actions are
selected. Implementors of this specification SHOULD document the selected. Implementors of this specification SHOULD document the
behaviour of their implementation in such cases. behaviour of their implementation in such cases.
Operators are encouraged to make use of the BGP policy framework Operators are encouraged to make use of the BGP policy framework
supported by their implementation in order to achieve a predictable supported by their implementation in order to achieve a predictable
behaviour (ie. match - replace - delete communities on administrative behaviour (ie. match - replace - delete communities on administrative
boundaries). See also Section 13. boundaries). See also Section 12.
8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks
Provider-based Layer 3 VPN networks, such as the ones using a BGP/ Provider-based Layer 3 VPN networks, such as the ones using a BGP/
MPLS IP VPN [RFC4364] control plane, may have different traffic MPLS IP VPN [RFC4364] control plane, may have different traffic
filtering requirements than Internet service providers. But also filtering requirements than Internet service providers. But also
Internet service providers may use those VPNs for scenarios like Internet service providers may use those VPNs for scenarios like
having the Internet routing table in a VRF, resulting in the same having the Internet routing table in a VRF, resulting in the same
traffic filtering requirements as defined for the global routing traffic filtering requirements as defined for the global routing
table environment within this document. This document defines an table environment within this document. This document defines an
additional BGP NLRI type (AFI=1, SAFI=134) value, which can be used additional BGP NLRI type (AFI=1, SAFI=134) value, which can be used
to propagate Flow Specification in a BGP/MPLS VPN environment. to propagate Flow Specification in a BGP/MPLS VPN environment.
The NLRI format for this address family consists of a fixed-length The NLRI format for this address family consists of a fixed-length
Route Distinguisher field (8 bytes) followed by the Flow Route Distinguisher field (8 octets) followed by the Flow
Specification NLRI value (Section 4.2). The NLRI length field shall Specification NLRI value (Section 4.2). The NLRI length field shall
include both the 8 bytes of the Route Distinguisher as well as the include both the 8 octets of the Route Distinguisher as well as the
subsequent Flow Specification NLRI value. The resulting encoding is subsequent Flow Specification NLRI value. The resulting encoding is
shown in Figure 7. shown in Figure 7.
+------------------------------+ +--------------------------------+
| length (0xnn or 0xfn nn) | | length (0xnn or 0xfn nn) |
+------------------------------+ +--------------------------------+
| Route Distinguisher (8 bytes)| | Route Distinguisher (8 octets) |
+------------------------------+ +--------------------------------+
| NLRI value (variable) | | NLRI value (variable) |
+------------------------------+ +--------------------------------+
Figure 7: Flow Specification NLRI for MPLS Figure 7: Flow Specification NLRI for MPLS
Propagation of this NLRI is controlled by matching Route Target Propagation of this NLRI is controlled by matching Route Target
extended communities associated with the BGP path advertisement with extended communities associated with the BGP path advertisement with
the VRF import policy, using the same mechanism as described in BGP/ the VRF import policy, using the same mechanism as described in BGP/
MPLS IP VPNs [RFC4364]. MPLS IP VPNs [RFC4364].
Flow Specifications received via this NLRI apply only to traffic that Flow Specifications received via this NLRI apply only to traffic that
belongs to the VRF(s) in which it is imported. By default, traffic belongs to the VRF(s) in which it is imported. By default, traffic
skipping to change at page 25, line 33 skipping to change at page 25, line 33
10. Error Handling 10. Error Handling
Error handling according to [RFC7606] and [RFC4760] applies to this Error handling according to [RFC7606] and [RFC4760] applies to this
specification. specification.
This document introduces Traffic Filtering Action Extended This document introduces Traffic Filtering Action Extended
Communities. Malformed Traffic Filtering Action Extended Communities Communities. Malformed Traffic Filtering Action Extended Communities
in the sense of [RFC7606] Section 7.14. are Extended Community values in the sense of [RFC7606] Section 7.14. are Extended Community values
that cannot be decoded according to Section 7 of this document. that cannot be decoded according to Section 7 of this document.
11. Future NLRI Extensions 11. IANA Considerations
Future Flow Specification extensions may introduce new Flow
Specification components. If a receiving BGP speaker decodes an
unknown Flow Specification component type it is unable to continue
decoding the following Flow Specification components in the same NLRI
value and MUST discard this NLRI value and all its components as
described in Section 4.2 for further processing. Since the NLRI
field encoding (Section 4) is defined in the form of a 2-tuple
<length, NLRI value> message decoding can skip over the NLRI value
and continue with subsequent NLRI and message decoding.
The specification of a new Flow Specification Component Type MUST
clearly identify what the criteria used to match packets forwarded by
the router is. This criteria should be meaningful across router hops
and not depend on values that change hop-by-hop such as TTL or Layer
2 encapsulation.
Such extensions SHOULD also specify a way to encode an "always-match"
match condition within the newly introduced components (this is a
match condition, encoded with the newly introduced components: If
present on its own, matches all flows). This match condition can be
used to propagate (and apply) certain Flow Specifications only if a
specific extension is known to the implementation.
12. IANA Considerations
This section complies with [RFC7153]. This section complies with [RFC7153].
12.1. AFI/SAFI Definitions 11.1. AFI/SAFI Definitions
IANA maintains a registry entitled "SAFI Values". For the purpose of IANA maintains a registry entitled "SAFI Values". For the purpose of
this work, IANA is requested to update the following SAFIs to read this work, IANA is requested to update the following SAFIs to read
according to the table below (Note: This document obsoletes both according to the table below (Note: This document obsoletes both
RFC7674 and RFC5575 and all references to those documents should be RFC7674 and RFC5575 and all references to those documents should be
deleted from the registry below): deleted from the registry below):
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
| Value | Name | Reference | | Value | Name | Reference |
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
| 133 | Dissemination of Flow Specification | [this | | 133 | Dissemination of Flow Specification | [this |
| | rules | document] | | | rules | document] |
| 134 | L3VPN Dissemination of Flow | [this | | 134 | L3VPN Dissemination of Flow | [this |
| | Specification rules | document] | | | Specification rules | document] |
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
Table 3: Registry: SAFI Values Table 3: Registry: SAFI Values
12.2. Flow Component Definitions 11.2. Flow Component Definitions
A Flow Specification consists of a sequence of flow components, which A Flow Specification consists of a sequence of flow components, which
are identified by a an 8-bit component type. IANA has created and are identified by a an 8-bit component type. IANA has created and
maintains a registry entitled "Flow Spec Component Types". IANA is maintains a registry entitled "Flow Spec Component Types". IANA is
requested to update the reference for this registry to [this requested to update the reference for this registry to [this
document]. Furthermore the references to the values should be document]. Furthermore the references to the values should be
updated according to the table below (Note: This document obsoletes updated according to the table below (Note: This document obsoletes
both RFC7674 and RFC5575 and all references to those documents should both RFC7674 and RFC5575 and all references to those documents should
be deleted from the registry below). be deleted from the registry below).
skipping to change at page 27, line 38 skipping to change at page 27, line 16
| Type Values | Policy | | Type Values | Policy |
+--------------+-------------------------------+ +--------------+-------------------------------+
| 0 | Reserved | | 0 | Reserved |
| [1 .. 12] | Defined by this specification | | [1 .. 12] | Defined by this specification |
| [13 .. 127] | Specification required | | [13 .. 127] | Specification required |
| [128 .. 255] | First Come First Served | | [128 .. 255] | First Come First Served |
+--------------+-------------------------------+ +--------------+-------------------------------+
Table 5: Flow Spec Component Types Policies Table 5: Flow Spec Component Types Policies
12.3. Extended Community Flow Specification Actions 11.3. Extended Community Flow Specification Actions
The Extended Community Flow Specification Action types defined in The Extended Community Flow Specification Action types defined in
this document consist of two parts: this document consist of two parts:
Type (BGP Transitive Extended Community Type) Type (BGP Transitive Extended Community Type)
Sub-Type Sub-Type
For the type-part, IANA maintains a registry entitled "BGP Transitive For the type-part, IANA maintains a registry entitled "BGP Transitive
Extended Community Types". For the purpose of this work (Section 7), Extended Community Types". For the purpose of this work (Section 7),
skipping to change at page 28, line 43 skipping to change at page 28, line 21
| Sub-Type | Name | Reference | | Sub-Type | Name | Reference |
| Value | | | | Value | | |
+----------+--------------------------------------------+-----------+ +----------+--------------------------------------------+-----------+
| 0x06 | Flow spec traffic-rate-bytes | [this | | 0x06 | Flow spec traffic-rate-bytes | [this |
| | | document] | | | | document] |
| TBD | Flow spec traffic-rate-packets | [this | | TBD | Flow spec traffic-rate-packets | [this |
| | | document] | | | | document] |
| 0x07 | Flow spec traffic-action (Use | [this | | 0x07 | Flow spec traffic-action (Use | [this |
| | of the "Value" field is defined in the | document] | | | of the "Value" field is defined in the | document] |
| | "Traffic Action Fields" registry) | | | | "Traffic Action Fields" registry) | |
| 0x08 | Flow spec rt-redirect AS-2byte | [this | | 0x08 | Flow spec rt-redirect | [this |
| | format | document] | | | AS-2octet format | document] |
| 0x09 | Flow spec traffic-remarking | [this | | 0x09 | Flow spec traffic-remarking | [this |
| | | document] | | | | document] |
+----------+--------------------------------------------+-----------+ +----------+--------------------------------------------+-----------+
Table 7: Registry: Generic Transitive Experimental Use Extended Table 7: Registry: Generic Transitive Experimental Use Extended
Community Sub-Types Community Sub-Types
+------------+----------------------------------------+-------------+ +------------+----------------------------------------+-------------+
| Sub-Type | Name | Reference | | Sub-Type | Name | Reference |
| Value | | | | Value | | |
+------------+----------------------------------------+-------------+ +------------+----------------------------------------+-------------+
| 0x08 | Flow spec rt-redirect IPv4 | [this | | 0x08 | Flow spec rt-redirect IPv4 | [this |
| | format | document] | | | format | document] |
+------------+----------------------------------------+-------------+ +------------+----------------------------------------+-------------+
Table 8: Registry: Generic Transitive Experimental Use Extended Table 8: Registry: Generic Transitive Experimental Use Extended
Community Part 2 Sub-Types Community Part 2 Sub-Types
+------------+----------------------------------------+-------------+ +------------+-----------------------------------------+------------+
| Sub-Type | Name | Reference | | Sub-Type | Name | Reference |
| Value | | | | Value | | |
+------------+----------------------------------------+-------------+ +------------+-----------------------------------------+------------+
| 0x08 | Flow spec rt-redirect AS- | [this | | 0x08 | Flow spec rt-redirect | [this |
| | 4byte format | document] | | | AS-4octet format | document] |
+------------+----------------------------------------+-------------+ +------------+-----------------------------------------+------------+
Table 9: Registry: Generic Transitive Experimental Use Extended Table 9: Registry: Generic Transitive Experimental Use Extended
Community Part 3 Sub-Types Community Part 3 Sub-Types
Furthermore IANA is requested to update the reference for the Furthermore IANA is requested to update the reference for the
registries "Generic Transitive Experimental Use Extended Community registries "Generic Transitive Experimental Use Extended Community
Part 2 Sub-Types" and "Generic Transitive Experimental Use Extended Part 2 Sub-Types" and "Generic Transitive Experimental Use Extended
Community Part 3 Sub-Types" to [this document]. Community Part 3 Sub-Types" to [this document].
The "traffic-action" extended community (Section 7.3) defined in this The "traffic-action" extended community (Section 7.3) defined in this
skipping to change at page 30, line 5 skipping to change at page 29, line 29
+-----+-----------------+-----------------+ +-----+-----------------+-----------------+
| Bit | Name | Reference | | Bit | Name | Reference |
+-----+-----------------+-----------------+ +-----+-----------------+-----------------+
| 47 | Terminal Action | [this document] | | 47 | Terminal Action | [this document] |
| 46 | Sample | [this document] | | 46 | Sample | [this document] |
+-----+-----------------+-----------------+ +-----+-----------------+-----------------+
Table 10: Registry: Traffic Action Fields Table 10: Registry: Traffic Action Fields
13. Security Considerations 12. Security Considerations
As long as Flow Specifications are restricted to match the As long as Flow Specifications are restricted to match the
corresponding unicast routing paths for the relevant prefixes corresponding unicast routing paths for the relevant prefixes
(Section 6), the security characteristics of this proposal are (Section 6), the security characteristics of this proposal are
equivalent to the existing security properties of BGP unicast equivalent to the existing security properties of BGP unicast
routing. Any relaxation of the validation procedure described in routing. Any relaxation of the validation procedure described in
Section 6 may allow unwanted Flow Specifications to be propagated and Section 6 may allow unwanted Flow Specifications to be propagated and
thus unwanted Traffic Filtering Actions may be applied to flows. thus unwanted Traffic Filtering Actions may be applied to flows.
Where the above mechanisms are not in place, this could open the door Where the above mechanisms are not in place, this could open the door
skipping to change at page 30, line 52 skipping to change at page 30, line 27
extend the AS_PATH. In such cases it is not possible to enforce the extend the AS_PATH. In such cases it is not possible to enforce the
left-most AS in the AS_PATH to be the neighbor AS (the AS of the left-most AS in the AS_PATH to be the neighbor AS (the AS of the
route server). Since the validation of Flow Specification route server). Since the validation of Flow Specification
(Section 6) depends on this, additional care must be taken. It is (Section 6) depends on this, additional care must be taken. It is
advised to use a strict inbound route policy in such scenarios. advised to use a strict inbound route policy in such scenarios.
Enabling firewall-like capabilities in routers without centralized Enabling firewall-like capabilities in routers without centralized
management could make certain failures harder to diagnose. For management could make certain failures harder to diagnose. For
example, it is possible to allow TCP packets to pass between a pair example, it is possible to allow TCP packets to pass between a pair
of addresses but not ICMP packets. It is also possible to permit of addresses but not ICMP packets. It is also possible to permit
packets smaller than 900 or greater than 1000 bytes to pass between a packets smaller than 900 or greater than 1000 octets to pass between
pair of addresses, but not packets whose length is in the range 900- a pair of addresses, but not packets whose length is in the range
1000. Such behavior may be confusing and these capabilities should 900- 1000. Such behavior may be confusing and these capabilities
be used with care whether manually configured or coordinated through should be used with care whether manually configured or coordinated
the protocol extensions described in this document. through the protocol extensions described in this document.
Flow Specification BGP speakers (e.g. automated DDoS controllers) not Flow Specification BGP speakers (e.g. automated DDoS controllers) not
properly programmed, algorithms that are not performing as expected, properly programmed, algorithms that are not performing as expected,
or simply rogue systems may announce unintended Flow Specifications, or simply rogue systems may announce unintended Flow Specifications,
send updates at a high rate or generate a high number of Flow send updates at a high rate or generate a high number of Flow
Specifications. This may stress the receiving systems, exceed their Specifications. This may stress the receiving systems, exceed their
maximum capacity or may lead to unwanted Traffic Filtering Actions maximum capacity or may lead to unwanted Traffic Filtering Actions
being applied to flows. being applied to flows.
When BGP decodes an unknown Flow Specification component type, as of
Section 4.2 it needs to discard the NLRI and skip over the remaining
undecoded octets to the following NLRI or to the end of the list.
Skipping over unknown octets of the to be discarded NLRI is the
specified behaviour for a Type NLRI in Section 5.4 [RFC7606]. While
this is not intrinsic to the Flow Specification NLRI in particular,
it needs to be pointed out that, carefully crafted wrong NLRI length
fields may lead to synchronisation issues between BGP senders and
receivers.
While the general verification of the Flow Specification NLRI is While the general verification of the Flow Specification NLRI is
specified in this document (Section 6) the Traffic Filtering Actions specified in this document (Section 6) the Traffic Filtering Actions
received by a third party may need custom verification or filtering. received by a third party may need custom verification or filtering.
In particular all non traffic-rate actions may allow a third party to In particular all non traffic-rate actions may allow a third party to
modify packet forwarding properties and potentially gain access to modify packet forwarding properties and potentially gain access to
other routing-tables/VPNs or undesired queues. This can be avoided other routing-tables/VPNs or undesired queues. This can be avoided
by proper filtering/screening of the Traffic Filtering Action by proper filtering/screening of the Traffic Filtering Action
communities at network borders and only exposing a predefined subset communities at network borders and only exposing a predefined subset
of Traffic Filtering Actions (see Section 7) to third parties. One of Traffic Filtering Actions (see Section 7) to third parties. One
way to achieve this is by mapping user-defined communities, that can way to achieve this is by mapping user-defined communities, that can
skipping to change at page 32, line 5 skipping to change at page 31, line 14
accepting Traffic Filtering Action extended communities from third accepting Traffic Filtering Action extended communities from third
parties. parties.
This extension adds additional information to Internet routers. This extension adds additional information to Internet routers.
These are limited in terms of the maximum number of data elements These are limited in terms of the maximum number of data elements
they can hold as well as the number of events they are able to they can hold as well as the number of events they are able to
process in a given unit of time. Service providers need to consider process in a given unit of time. Service providers need to consider
the maximum capacity of their devices and may need to limit the the maximum capacity of their devices and may need to limit the
number of Flow Specifications accepted and processed. number of Flow Specifications accepted and processed.
14. Contributors 13. Contributors
Barry Greene, Pedro Marques, Jared Mauch and Nischal Sheth were Barry Greene, Pedro Marques, Jared Mauch and Nischal Sheth were
authors on [RFC5575], and therefore are contributing authors on this authors on [RFC5575], and therefore are contributing authors on this
document. document.
15. Acknowledgements 14. Acknowledgements
The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris
Morrow, Charlie Kaufman, and David Smith for their comments for the Morrow, Charlie Kaufman, and David Smith for their comments for the
comments on the original [RFC5575]. Chaitanya Kodeboyina helped comments on the original [RFC5575]. Chaitanya Kodeboyina helped
design the flow validation procedure; and Steven Lin and Jim Washburn design the flow validation procedure; and Steven Lin and Jim Washburn
ironed out all the details necessary to produce a working ironed out all the details necessary to produce a working
implementation in the original [RFC5575]. implementation in the original [RFC5575].
A packet rate Traffic Filtering Action was also described in a Flow A packet rate Traffic Filtering Action was also described in a Flow
Specification extension draft and the authors like to thank Wesley Specification extension draft and the authors like to thank Wesley
Eddy, Justin Dailey and Gilbert Clark for their work. Eddy, Justin Dailey and Gilbert Clark for their work.
Additionally, the authors would like to thank Alexander Mayrhofer, Additionally, the authors would like to thank Alexander Mayrhofer,
Nicolas Fevrier, Job Snijders, Jeffrey Haas and Adam Chappell for Nicolas Fevrier, Job Snijders, Jeffrey Haas and Adam Chappell for
their comments and review. their comments and review.
16. References 15. References
16.1. Normative References 15.1. Normative References
[IEEE.754.1985] [IEEE.754.1985]
IEEE, "Standard for Binary Floating-Point Arithmetic", IEEE, "Standard for Binary Floating-Point Arithmetic",
IEEE 754-1985, August 1985. IEEE 754-1985, August 1985.
[ISO_IEC_9899] [ISO_IEC_9899]
ISO, "Information technology -- Programming languages -- ISO, "Information technology -- Programming languages --
C", ISO/IEC 9899:2018, June 2018. C", ISO/IEC 9899:2018, June 2018.
[RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768,
skipping to change at page 34, line 19 skipping to change at page 33, line 28
[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>.
16.2. Informative References 15.2. Informative References
[I-D.ietf-idr-flow-spec-v6] [I-D.ietf-idr-flow-spec-v6]
Loibl, C., Raszuk, R., and S. Hares, "Dissemination of Loibl, C., Raszuk, R., and S. Hares, "Dissemination of
Flow Specification Rules for IPv6", draft-ietf-idr-flow- Flow Specification Rules for IPv6", draft-ietf-idr-flow-
spec-v6-10 (work in progress), November 2019. spec-v6-10 (work in progress), November 2019.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005, RFC 4303, DOI 10.17487/RFC4303, December 2005,
<https://www.rfc-editor.org/info/rfc4303>. <https://www.rfc-editor.org/info/rfc4303>.
skipping to change at page 34, line 48 skipping to change at page 34, line 9
<https://www.rfc-editor.org/info/rfc6811>. <https://www.rfc-editor.org/info/rfc6811>.
[RFC7674] Haas, J., Ed., "Clarification of the Flowspec Redirect [RFC7674] Haas, J., Ed., "Clarification of the Flowspec Redirect
Extended Community", RFC 7674, DOI 10.17487/RFC7674, Extended Community", RFC 7674, DOI 10.17487/RFC7674,
October 2015, <https://www.rfc-editor.org/info/rfc7674>. October 2015, <https://www.rfc-editor.org/info/rfc7674>.
[RFC8205] Lepinski, M., Ed. and K. Sriram, Ed., "BGPsec Protocol [RFC8205] Lepinski, M., Ed. and K. Sriram, Ed., "BGPsec Protocol
Specification", RFC 8205, DOI 10.17487/RFC8205, September Specification", RFC 8205, DOI 10.17487/RFC8205, September
2017, <https://www.rfc-editor.org/info/rfc8205>. 2017, <https://www.rfc-editor.org/info/rfc8205>.
16.3. URIs 15.3. URIs
[1] https://github.com/stoffi92/flowspec-cmp [1] https://github.com/stoffi92/flowspec-cmp
Appendix A. Python code: flow_rule_cmp Appendix A. Python code: flow_rule_cmp
<CODE BEGINS> <CODE BEGINS>
""" """
Copyright (c) 2019 IETF Trust and the persons identified as authors of Copyright (c) 2019 IETF Trust and the persons identified as authors of
the code. All rights reserved. the code. All rights reserved.
skipping to change at page 36, line 35 skipping to change at page 35, line 44
This document includes numerous editorial changes to [RFC5575]. It This document includes numerous editorial changes to [RFC5575]. It
also completely incorporates the redirect action clarification also completely incorporates the redirect action clarification
document [RFC7674]. It is recommended to read the entire document. document [RFC7674]. It is recommended to read the entire document.
The authors, however want to point out the following technical The authors, however want to point out the following technical
changes to [RFC5575]: changes to [RFC5575]:
Section 1 introduces the Flow Specification NLRI. In [RFC5575] Section 1 introduces the Flow Specification NLRI. In [RFC5575]
this NLRI was defined as an opaque-key in BGPs database. This this NLRI was defined as an opaque-key in BGPs database. This
specification has removed all references to a opaque-key property. specification has removed all references to a opaque-key property.
BGP is able to understand the NLRI encoding. This change also BGP is able to understand the NLRI encoding.
resulted in a new section regarding error handling and
extensibility (Section 10 and Section 11).
Section 4.2.2.3 defines a numeric operator and comparison bit Section 4.2.1.1 defines a numeric operator and comparison bit
combinations. In [RFC5575] the meaning of those bit combination combinations. In [RFC5575] the meaning of those bit combination
was not explicitly defined and left open to the reader. was not explicitly defined and left open to the reader.
Section 4.2.2.3 - Section 4.2.2.8, Section 4.2.2.10, Section 4.2.2.3 - Section 4.2.2.8, Section 4.2.2.10,
Section 4.2.2.11 make use of the above numeric operator. The Section 4.2.2.11 make use of the above numeric operator. The
allowed length of the comparison value was not consistently allowed length of the comparison value was not consistently
defined in [RFC5575]. defined in [RFC5575].
Section 7 defines all Traffic Filtering Action Extended Section 7 defines all Traffic Filtering Action Extended
communities as transitive extended communities. [RFC5575] defined communities as transitive extended communities. [RFC5575] defined
skipping to change at page 37, line 23 skipping to change at page 36, line 29
route-target. This section also completely incorporates the route-target. This section also completely incorporates the
[RFC7674] clarifications of the Flowspec Redirect Extended [RFC7674] clarifications of the Flowspec Redirect Extended
Community. Community.
Section 7.7 contains general considerations on interfering traffic Section 7.7 contains general considerations on interfering traffic
actions. Section 7.3 also cross-references this section. actions. Section 7.3 also cross-references this section.
[RFC5575] did not mention this. [RFC5575] did not mention this.
Section 10 contains new error handling. Section 10 contains new error handling.
Section 11 describes graceful handling of unknown Flow
Specification components to allow future extensions.
Authors' Addresses Authors' Addresses
Christoph Loibl Christoph Loibl
Next Layer Communications Next Layer Communications
Mariahilfer Guertel 37/7 Mariahilfer Guertel 37/7
Vienna 1150 Vienna 1150
AT AT
Phone: +43 664 1176414 Phone: +43 664 1176414
Email: cl@tix.at Email: cl@tix.at
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