IDR Working Group
Internet Engineering Task Force (IETF) C. Loibl, Ed.
Internet-Draft
Request for Comments: 8956 next layer Telekom GmbH
Updates: I-D.ietf-idr-rfc5575bis (if 8955 R. Raszuk, Ed.
approved) Bloomberg LP
Intended status:
Category: Standards Track NTT Network Innovations
ISSN: 2070-1721 S. Hares, Ed.
Expires: June 17, 2021
Huawei
December 14, 2020
Dissemination of Flow Specification Rules for IPv6
draft-ietf-idr-flow-spec-v6-22
Abstract
Dissemination
"Dissemination of Flow Specification Rules I-D.ietf-idr-rfc5575bis Rules" (RFC 8955) provides a
Border Gateway Protocol (BGP) extension for the propagation of
traffic flow information for the purpose of rate limiting or
filtering IPv4 protocol data packets.
This document extends I-D.ietf-idr-rfc5575bis RFC 8955 with IPv6 functionality. It also
updates I-D.ietf-idr-rfc5575bis RFC 8955 by changing the IANA Flow Spec Component Types
registry.
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 an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list It represents the consensus of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid the IETF community. It has
received public review and has been approved for a maximum publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of six months RFC 7841.
Information about the current status of this document, any errata,
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 17, 2021.
https://www.rfc-editor.org/info/rfc8956.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Definitions of Terms Used in This Memo . . . . . . . . . 3
2. IPv6 Flow Specification encoding Encoding in BGP . . . . . . . . . . . 3
3. IPv6 Flow Specification components . . . . . . . . . . . . . 3 Components
3.1. Type 1 - Destination IPv6 Prefix . . . . . . . . . . . . 4
3.2. Type 2 - Source IPv6 Prefix . . . . . . . . . . . . . . . 4
3.3. Type 3 - Upper-Layer Protocol . . . . . . . . . . . . . . 5
3.4. Type 7 - ICMPv6 Type . . . . . . . . . . . . . . . . . . 5
3.5. Type 8 - ICMPv6 Code . . . . . . . . . . . . . . . . . . 5
3.6. Type 12 - Fragment . . . . . . . . . . . . . . . . . . . 6
3.7. Type 13 - Flow Label (new) . . . . . . . . . . . . . . . 7
3.8. Encoding Example . . . . . . . . . . . . . . . . . . . . 7 Examples
4. Ordering of Flow Specifications . . . . . . . . . . . . . . . 9
5. Validation Procedure . . . . . . . . . . . . . . . . . . . . 10
6. IPv6 Traffic Filtering Action changes . . . . . . . . . . . . 10 Changes
6.1. Redirect IPv6 (rt-redirect-ipv6) Type TBD . . . . . . . . 10 0x000d
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11
8.1. Flow Spec IPv6 Component Types . . . . . . . . . . . . . 11
8.1.1. Registry Template . . . . . . . . . . . . . . . . . . 11
8.1.2. Registry Contents . . . . . . . . . . . . . . . . . . 11
8.2. IPv6-Address-Specific Extended Community Flow Spec IPv6
Actions . . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . 14
11.2. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Appendix A. Example python code: Python Code: flow_rule_cmp_v6 . . . . . . . 16
Acknowledgments
Contributors
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 19
1. Introduction
The growing amount of IPv6 traffic in private and public networks
requires the extension of tools used in IPv4-only networks to also
support IPv6 data packets.
This document analyzes the differences between describing IPv6
[RFC8200] flows and those of IPv4 packets. It specifies new Border
Gateway Protocol [RFC4271] encoding formats to enable Dissemination "Dissemination
of Flow Specification Rules [I-D.ietf-idr-rfc5575bis] Rules" [RFC8955] for IPv6.
This specification is an extension of the base
[I-D.ietf-idr-rfc5575bis]. established in
[RFC8955]. It only defines the delta changes required to support IPv6
IPv6, while all other definitions and operation mechanisms of Dissemination
"Dissemination of Flow Specification Rules Rules" will remain in the main
specification and will not be repeated here.
1.1. Definitions of Terms Used in This Memo
AFI -
AFI: Address Family Identifier.
AS - Identifier
AS: Autonomous System.
NLRI - System
NLRI: Network Layer Reachability Information.
SAFI - Information
SAFI: Subsequent Address Family Identifier.
VRF - Identifier
VRF: Virtual Routing and Forwarding instance.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. IPv6 Flow Specification encoding Encoding in BGP
[I-D.ietf-idr-rfc5575bis]
[RFC8955] defines SAFIs 133 (Dissemination of Flow
Specification) Specification
rules) and 134 (L3VPN Dissemination of Flow Specification) Specification rules) in
order to carry the corresponding Flow Specification.
Implementations wishing to exchange IPv6 Flow Specifications MUST use
BGP's Capability Advertisement facility to exchange the Multiprotocol
Extension Capability Code (Code 1) 1), as defined in [RFC4760]. The
(AFI, SAFI) pair carried in the Multiprotocol Extension Capability
MUST be: be (AFI=2, SAFI=133) for IPv6 Flow Specification, Specification rules and
(AFI=2, SAFI=134) for VPNv6 L3VPN Dissemination of Flow Specification. Specification
rules.
3. IPv6 Flow Specification components Components
The encoding of each of the components begins with a type Type field (1
octet) followed by a variable length parameter. The following
sections define component types and parameter encodings for IPv6.
Types 4 (Port), 5 (Destination Port), 6 (Source Port), 9 (TCP flags), Flags),
10 (Packet length) Length), and 11 (DSCP), as defined in
[I-D.ietf-idr-rfc5575bis], [RFC8955], also
apply to IPv6. Note that IANA is
requested to update has updated the "Flow Spec Component
Types" registry in order to contain both IPv4 and IPv6 Flow
Specification component type numbers in a single registry
(Section 8).
3.1. Type 1 - Destination IPv6 Prefix
Encoding: <type (1 octet), length (1 octet), offset (1 octet),
pattern (variable), padding(variable) padding (variable) >
Defines
This defines the destination prefix to match. The offset has been
defined to allow for flexible matching to portions of an IPv6 address
where one is required to skip over the first N bits of the address (these address.
(These bits skipped are often indicated as "don't care" bits). bits.) This
can be especially useful where part of the IPv6 address consists of
an embedded IPv4 address address, and matching needs to happen only on the
embedded IPv4 address. The encoded pattern contains enough octets
for the bits used in matching (length minus offset bits).
length - The length field
length: This indicates the N-th most significant bit in the
address where bitwise pattern matching stops.
offset - The offset field
offset: This indicates the number of most significant address bits
to skip before bitwise pattern matching starts.
pattern - Contains
pattern: This contains the matching pattern. The length of the
pattern is defined by the number of bits needed for
pattern matching (length minus offset).
padding - The
padding: This contains the minimum number of bits required to pad
the component to an octet boundary. Padding bits MUST be
0 on encoding and MUST be ignored on decoding.
If length = 0 and offset = 0 0, this component matches every address, otherwise address;
otherwise, length MUST be in the range offset < length < 129 or the
component is malformed.
Note: This Flow Specification component can be represented by the
notation ipv6address/length if offset is 0, 0 or ipv6address/offset-
length. The ipv6address in this notation is the textual IPv6
representation of the pattern shifted to the right by the number of
offset bits. See also Section 3.8.
3.2. Type 2 - Source IPv6 Prefix
Encoding: <type (1 octet), length (1 octet), offset (1 octet),
pattern (variable), padding(variable) padding (variable) >
Defines
This defines the source prefix to match. The length, offset, pattern
pattern, and padding are the same as in Section 3.1.
3.3. Type 3 - Upper-Layer Protocol
Encoding: <type (1 octet), [numeric_op, value]+>
Contains
This contains a list of {numeric_op, value} pairs that are used to
match the first Next Header value octet in IPv6 packets that is not
an extension header and thus indicates that the next item in the
packet is the corresponding upper-layer header (see [RFC8200] Section 4). 4 of
[RFC8200]).
This component uses the Numeric Operator (numeric_op) described in
[I-D.ietf-idr-rfc5575bis]
Section 4.2.1.1. 4.2.1.1 of [RFC8955]. Type 3 component values SHOULD be
encoded as a single octet (numeric_op len=00).
Note: While IPv6 allows for more than one Next Header field in the
packet, the main goal of the Type 3 Flow Specification component is
to match on the first upper-layer IP protocol value. Therefore Therefore, the
definition is limited to match only on this specific Next Header
field in the packet.
3.4. Type 7 - ICMPv6 Type
Encoding: <type (1 octet), [numeric_op, value]+>
Defines
This defines a list of {numeric_op, value} pairs used to match the type
Type field of an ICMPv6 packet (see also [RFC4443] Section 2.1). 2.1 of [RFC4443]).
This component uses the Numeric Operator (numeric_op) described in
[I-D.ietf-idr-rfc5575bis]
Section 4.2.1.1. 4.2.1.1 of [RFC8955]. Type 7 component values SHOULD be
encoded as a single octet (numeric_op len=00).
In case of the presence of the ICMPv6 Type component type component, only ICMPv6
packets can match the entire Flow Specification. The ICMPv6 Type type
component, if present, never matches when the packet's upper-layer IP
protocol value is not 58 (ICMPv6), if the packet is fragmented and
this is not the first fragment, or if the system is unable to locate
the transport header. Different implementations may or may not be
able to decode the transport header.
3.5. Type 8 - ICMPv6 Code
Encoding: <type (1 octet), [numeric_op, value]+>
Defines
This defines a list of {numeric_op, value} pairs used to match the
code field of an ICMPv6 packet (see also [RFC4443] Section 2.1). 2.1 of [RFC4443]).
This component uses the Numeric Operator (numeric_op) described in
[I-D.ietf-idr-rfc5575bis]
Section 4.2.1.1. 4.2.1.1 of [RFC8955]. Type 8 component values SHOULD be
encoded as a single octet (numeric_op len=00).
In case of the presence of the ICMPv6 Code component code component, only ICMPv6
packets can match the entire Flow Specification. The ICMPv6 code
component, if present, never matches when the packet's upper-layer IP
protocol value is not 58 (ICMPv6), if the packet is fragmented and
this is not the first fragment, or if the system is unable to locate
the transport header. Different implementations may or may not be
able to decode the transport header.
3.6. Type 12 - Fragment
Encoding: <type (1 octet), [bitmask_op, bitmask]+>
Defines
This defines a list of {bitmask_op, bitmask} pairs used to match
specific IP fragments.
This component uses the Bitmask Operator (bitmask_op) described in
[I-D.ietf-idr-rfc5575bis]
Section 4.2.1.2. 4.2.1.2 of [RFC8955]. The Type 12 component bitmask MUST be
encoded as a single octet bitmask (bitmask_op len=00).
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| 0 | 0 | 0 | 0 |LF |FF |IsF| 0 |
+---+---+---+---+---+---+---+---+
Figure 1: Fragment Bitmask Operand
Bitmask values:
IsF -
IsF: Is a fragment other than the first - -- match if IPv6 Fragment
Header ([RFC8200] Section 4.5) (Section 4.5 of [RFC8200]) Fragment Offset is not 0
FF -
FF: First fragment - -- match if IPv6 Fragment Header ([RFC8200]
Section 4.5) (Section 4.5 of
[RFC8200]) Fragment Offset is 0 AND M flag is 1
LF -
LF: Last fragment - -- match if IPv6 Fragment Header ([RFC8200]
Section 4.5) (Section 4.5 of
[RFC8200]) Fragment Offset is not 0 AND M flag is 0
0 -
0: MUST be set to 0 on NLRI encoding, encoding and MUST be ignored during
decoding
3.7. Type 13 - Flow Label (new)
Encoding: <type (1 octet), [numeric_op, value]+>
Contains
This contains a list of {numeric_op, value} pairs that are used to
match the 20-bit Flow Label IPv6 header field ([RFC8200] Section 3). (Section 3 of
[RFC8200]).
This component uses the Numeric Operator (numeric_op) described in
[I-D.ietf-idr-rfc5575bis]
Section 4.2.1.1. 4.2.1.1 of [RFC8955]. Type 13 component values SHOULD be
encoded as 4-octet quantities (numeric_op len=10).
3.8. Encoding Example Examples
3.8.1. Example 1
The following example demonstrates the prefix encoding for: "packets for packets
from ::1234:5678:9a00:0/64-104 to 2001:db8::/32 and upper-layer- upper-layer
protocol tcp".
+--------+----------------------+-------------------------+----------+ tcp.
+======+======================+=========================+==========+
| length len | destination | source | ul-proto |
+--------+----------------------+-------------------------+----------+
+======+======================+=========================+==========+
| 0x12 | 01 20 00 20 01 0D B8 | 02 68 40 12 34 56 78 9A | 03 81 06 |
+--------+----------------------+-------------------------+----------+
+------+----------------------+-------------------------+----------+
Table 1
Decoded:
+-------+------------+-------------------------------+
+=======+============+=================================+
| Value | | |
+-------+------------+-------------------------------+
+=======+============+=================================+
| 0x12 | length | 18 octets (len<240 1-octet) (if len<240, 1 octet) |
+-------+------------+---------------------------------+
| 0x01 | type | Type 1 - Dest. IPv6 Prefix |
+-------+------------+---------------------------------+
| 0x20 | length | 32 bit bits |
+-------+------------+---------------------------------+
| 0x00 | offset | 0 bit bits |
+-------+------------+---------------------------------+
| 0x20 | pattern | |
+-------+------------+---------------------------------+
| 0x01 | pattern | |
+-------+------------+---------------------------------+
| 0x0D | pattern | |
+-------+------------+---------------------------------+
| 0xB8 | pattern | (no padding needed) |
+-------+------------+---------------------------------+
| 0x02 | type | Type 2 - Source IPv6 Prefix |
+-------+------------+---------------------------------+
| 0x68 | length | 104 bit bits |
+-------+------------+---------------------------------+
| 0x40 | offset | 64 bit bits |
+-------+------------+---------------------------------+
| 0x12 | pattern | |
+-------+------------+---------------------------------+
| 0x34 | pattern | |
+-------+------------+---------------------------------+
| 0x56 | pattern | |
+-------+------------+---------------------------------+
| 0x78 | pattern | |
+-------+------------+---------------------------------+
| 0x9A | pattern | (no padding needed) |
+-------+------------+---------------------------------+
| 0x03 | type | Type 3 - upper-layer-proto Upper-Layer Protocol |
+-------+------------+---------------------------------+
| 0x81 | numeric_op | end-of-list, value size=1, == |
+-------+------------+---------------------------------+
| 0x06 | value | 06 |
+-------+------------+-------------------------------+
+-------+------------+---------------------------------+
Table 2
This constitutes a an NLRI with a an NLRI length of 18 octets.
Padding is not needed either for the destination prefix pattern
(length - offset = 32 bit) bits) or for the source prefix pattern (length
- offset = 40 bit), bits), as both patterns end on an octet boundary.
3.8.2. Example 2
The following example demonstrates the prefix encoding for: "all for all
packets from ::1234:5678:9a00:0/65-104 to 2001:db8::/32".
+--------+----------------------+-------------------------+ 2001:db8::/32.
+========+======================+=========================+
| length | destination | source |
+--------+----------------------+-------------------------+
+========+======================+=========================+
| 0x0f | 01 20 00 20 01 0D B8 | 02 68 41 24 68 ac f1 34 |
+--------+----------------------+-------------------------+
Table 3
Decoded:
+-------+-------------+-------------------------------+
+=======+=============+=================================+
| Value | | |
+-------+-------------+-------------------------------+
+=======+=============+=================================+
| 0x0f | length | 15 octets (len<240 1-octet) (if len<240, 1 octet) |
+-------+-------------+---------------------------------+
| 0x01 | type | Type 1 - Dest. IPv6 Prefix |
+-------+-------------+---------------------------------+
| 0x20 | length | 32 bit bits |
+-------+-------------+---------------------------------+
| 0x00 | offset | 0 bit bits |
+-------+-------------+---------------------------------+
| 0x20 | pattern | |
+-------+-------------+---------------------------------+
| 0x01 | pattern | |
+-------+-------------+---------------------------------+
| 0x0D | pattern | |
+-------+-------------+---------------------------------+
| 0xB8 | pattern | (no padding needed) |
+-------+-------------+---------------------------------+
| 0x02 | type | Type 2 - Source IPv6 Prefix |
+-------+-------------+---------------------------------+
| 0x68 | length | 104 bit bits |
+-------+-------------+---------------------------------+
| 0x41 | offset | 65 bit bits |
+-------+-------------+---------------------------------+
| 0x24 | pattern | |
+-------+-------------+---------------------------------+
| 0x68 | pattern | |
+-------+-------------+---------------------------------+
| 0xac | pattern | |
+-------+-------------+---------------------------------+
| 0xf1 | pattern | |
+-------+-------------+---------------------------------+
| 0x34 | pattern/pad | (contains 1 bit of padding) |
+-------+-------------+-------------------------------+
+-------+-------------+---------------------------------+
Table 4
This constitutes a an NLRI with a an NLRI length of 15 octets.
The source prefix pattern is 104 - 65 = 39 bits in length. After the
pattern
pattern, one bit of padding needs to be added so that the component
ends on a an octet boundary. However, only the first 39 bits are
actually used for bitwise pattern matching matching, starting with a 65 bit 65-bit
offset from the topmost bit of the address.
4. Ordering of Flow Specifications
The definition for the order of traffic filtering rules from
[I-D.ietf-idr-rfc5575bis]
Section 5.1 of [RFC8955] is reused with new consideration for the
IPv6 prefix offset. As long as the offsets are equal, the comparison
is the same, retaining longest-prefix-match semantics. If the
offsets are not equal, the lowest offset has precedence, as this Flow
Specification matches the most significant bit.
The code in Appendix A shows a Python3 implementation of the
resulting comparison algorithm. The full code was tested with Python
3.7.2 and can be obtained at https://github.com/stoffi92/draft-ietf-
idr-flow-spec-v6/tree/master/flowspec-cmp [1]. <https://github.com/stoffi92/draft-ietf-
idr-flow-spec-v6/tree/master/flowspec-cmp>.
5. Validation Procedure
The validation procedure is the same as specified in
[I-D.ietf-idr-rfc5575bis] Section 6 of
[RFC8955] with the exception that item a) of the validation procedure
should now read as follows:
| a) A destination prefix component with offset=0 is embedded in
| the Flow Specification
6. IPv6 Traffic Filtering Action changes Changes
Traffic Filtering Actions from [I-D.ietf-idr-rfc5575bis] Section 7 of [RFC8955] can also be
applied to IPv6 Flow Specifications. To allow an IPv6-
Address-Specific IPv6-Address-
Specific Route-Target, a new Traffic Filtering Action IPv6-
Address-Specific IPv6-Address-
Specific Extended Community [RFC5701] is specified in Section 6.1 below.
6.1. Redirect IPv6 (rt-redirect-ipv6) Type TBD 0x000d
The redirect IPv6-Address-Specific Extended Community allows the
traffic to be redirected to a VRF routing instance that lists the
specified IPv6-Address-Specific Route-Target in its import policy.
If several local instances match this criteria, the choice between
them is a local matter (for example, the instance with the lowest
Route Distinguisher value can be elected).
This IPv6-Address-Specific Extended Community uses the same encoding
as the IPv6-Address-Specific Route-Target Extended Community
[RFC5701] Section
(Section 2 of [RFC5701]) with the Type value always TBD. 0x000d.
The Local Administrator sub-field subfield contains a number from a numbering
space that is administered by the organization to which the IP
address carried in the Global Administrator sub-field subfield has been
assigned by an appropriate authority.
Interferes with: All BGP Flow Specification redirect Traffic
Filtering Actions (with itself and those specified in
[I-D.ietf-idr-rfc5575bis] Section 7.4). 7.4 of
[RFC8955]).
7. Security Considerations
This document extends the functionality in [I-D.ietf-idr-rfc5575bis] [RFC8955] to be applicable
to IPv6 data packets. The same Security
Considerations security considerations from [I-D.ietf-idr-rfc5575bis]
[RFC8955] now also apply to IPv6 networks.
[RFC7112] describes the impact of oversized IPv6 header chains when
trying to match on the transport header; [RFC8200] Section 4.5 of [RFC8200]
also requires that the first fragment must include the upper-layer header
header, but there could be wrongly formatted packets not respecting
[RFC8200]. IPv6 Flow Specification component type Type 3 (Section 3.3)
will not be enforced for those illegal packets. Moreover, there are
hardware limitations in several routers ([RFC8883] Section 1) (Section 1 of [RFC8883]) that
may make it impossible to enforce a policy signaled by a type Type 3 Flow
Specification component or Flow Specification components that match
on upper-layer properties of the packet.
8. IANA Considerations
This section complies with [RFC7153].
8.1. Flow Spec IPv6 Component Types
IANA has created and maintains a registry entitled "Flow Spec
Component Types". IANA is requested to add [this document] to the has added this document as a reference for this
that registry. Furthermore Furthermore, the registry should be
rewritten has been updated to also
contain the IPv6 Flow Specification Component Types as described
below. The registration procedure should remain remains unchanged.
8.1.1. Registry Template
Type Value:
Contains contains the assigned Flow Specification component type value.
value
IPv4 Name:
Contains contains the associated IPv4 Flow Specification
component name as specified in [I-D.ietf-idr-rfc5575bis]. [RFC8955]
IPv6 Name:
Contains contains the associated IPv6 Flow Specification
component name as specified in this document. document
Reference:
Contains referenced contains references to the specifications. specifications
8.1.2. Registry Contents
+
Type Value: 0
+
IPv4 Name: Reserved
+
IPv6 Name: Reserved
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 1
+
IPv4 Name: Destination Prefix
+
IPv6 Name: Destination IPv6 Prefix
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 2
+
IPv4 Name: Source Prefix
+
IPv6 Name: Source IPv6 Prefix
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 3
+
IPv4 Name: IP Protocol
+
IPv6 Name: Upper-Layer Protocol
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 4
+
IPv4 Name: Port
+
IPv6 Name: Port
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 5
+
IPv4 Name: Destination Port
+
IPv6 Name: Destination Port
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 6
+
IPv4 Name: Source Port
+
IPv6 Name: Source Port
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 7
+
IPv4 Name: ICMP Type
+
IPv6 Name: ICMPv6 Type
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 8
+
IPv4 Name: ICMP Code
+
IPv6 Name: ICMPv6 Code
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 9
+
IPv4 Name: TCP Flags
+
IPv6 Name: TCP Flags
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 10
+
IPv4 Name: Packet Length
+
IPv6 Name: Packet Length
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 11
+
IPv4 Name: DSCP
+
IPv6 Name: DSCP
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 12
+
IPv4 Name: Fragment
+
IPv6 Name: Fragment
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document]
+ [RFC8955], RFC 8956
Type Value: 13
+
IPv4 Name: Unassigned
+
IPv6 Name: Flow Label
+
Reference: [this document]
+ RFC 8956
Type Value: 14-254
+
IPv4 Name: Unassigned
+
IPv6 Name: Unassigned
+ Reference:
+
Type Value: 255
+
IPv4 Name: Reserved
+
IPv6 Name: Reserved
+
Reference: [I-D.ietf-idr-rfc5575bis] [this document] [RFC8955], RFC 8956
8.2. IPv6-Address-Specific Extended Community Flow Spec IPv6 Actions
IANA maintains a registry entitled "Transitive IPv6-Address-Specific
Extended Community Types". For the purpose of this work, IANA is
requested to assign has
assigned a new value:
+------------+-----------------------------------+-----------------+
+============+===================================+===========+
| Type Value | Name | Reference |
+------------+-----------------------------------+-----------------+
+============+===================================+===========+
| TBD 0x000d | Flow spec rt-redirect-ipv6 format | [this document] RFC 8956 |
+------------+-----------------------------------+-----------------+
+------------+-----------------------------------+-----------+
Table 1: Registry: 5: Transitive IPv6-Address-Specific Extended
Community Types Registry
9. Acknowledgements
Authors would like to thank Pedro Marques, Hannes Gredler, Bruno
Rijsman, Brian Carpenter, and Thomas Mangin for their valuable input.
10. Contributors
Danny McPherson
Verisign, Inc.
Email: dmcpherson@verisign.com
Burjiz Pithawala
Individual
Email: burjizp@gmail.com
Andy Karch
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
USA
Email: akarch@cisco.com
11. References
11.1. Normative References
[I-D.ietf-idr-rfc5575bis]
Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
Bacher, "Dissemination of Flow Specification Rules",
draft-ietf-idr-rfc5575bis-27 (work in progress), October
2020.
[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>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<https://www.rfc-editor.org/info/rfc4271>.
[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>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
[RFC5701] Rekhter, Y., "IPv6 Address Specific BGP Extended Community
Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009,
<https://www.rfc-editor.org/info/rfc5701>.
[RFC7112] Gont, F., Manral, V., and R. Bonica, "Implications of
Oversized IPv6 Header Chains", RFC 7112,
DOI 10.17487/RFC7112, January 2014,
<https://www.rfc-editor.org/info/rfc7112>.
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <https://www.rfc-editor.org/info/rfc7153>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[RFC8883] Herbert, T., "ICMPv6 Errors for Discarding Packets Due to
Processing Limits", RFC 8883, DOI 10.17487/RFC8883,
September 2020, <https://www.rfc-editor.org/info/rfc8883>.
11.2. URIs
[1] https://github.com/stoffi92/draft-ietf-idr-flow-spec-
v6/tree/master/flowspec-cmp
[RFC8955] Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
Bacher, "Dissemination of Flow Specification Rules",
RFC 8955, DOI 10.17487/RFC8955, December 2020,
<https://www.rfc-editor.org/info/rfc8955>.
Appendix A. Example python code: Python Code: flow_rule_cmp_v6
<CODE BEGINS>
"""
Copyright (c) 2020 IETF Trust and the persons identified as authors
of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license
terms contained in, the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
"""
import itertools
import collections
import ipaddress
EQUAL = 0
A_HAS_PRECEDENCE = 1
B_HAS_PRECEDENCE = 2
IP_DESTINATION = 1
IP_SOURCE = 2
FS_component = collections.namedtuple('FS_component',
'component_type value')
class FS_IPv6_prefix_component:
def __init__(self, prefix, offset=0,
component_type=IP_DESTINATION):
self.offset = offset
self.component_type = component_type
# make sure if offset != 0 that none of the
# first offset bits are set in the prefix
self.value = prefix
if offset != 0:
i = ipaddress.IPv6Interface(
(self.value.network_address, offset))
if i.network.network_address != \
ipaddress.ip_address('0::0'):
raise ValueError('Bits set in the offset')
class FS_nlri(object):
"""
FS_nlri class implementation that allows sorting.
By calling .sort() on an array of FS_nlri objects these
will be sorted according to the flow_rule_cmp algorithm.
Example:
nlri = [ FS_nlri(components=[
FS_component(component_type=4,
value=bytearray([0,1,2,3,4,5,6])),
]),
FS_nlri(components=[
FS_component(component_type=5,
value=bytearray([0,1,2,3,4,5,6])),
FS_component(component_type=6,
value=bytearray([0,1,2,3,4,5,6])),
]),
]
nlri.sort() # sorts the array according to the algorithm
"""
def __init__(self, components = None):
"""
components: list of type FS_component
"""
self.components = components
def __lt__(self, other):
# use the below algorithm for sorting
result = flow_rule_cmp_v6(self, other)
if result == B_HAS_PRECEDENCE:
return True
else:
return False
def flow_rule_cmp_v6(a, b):
"""
Implementation of the flowspec sorting algorithm in
draft-ietf-idr-flow-spec-v6.
RFC 8956.
"""
for comp_a, comp_b in itertools.zip_longest(a.components,
b.components):
# If a component type does not exist in one rule
# this rule has lower precedence
if not comp_a:
return B_HAS_PRECEDENCE
if not comp_b:
return A_HAS_PRECEDENCE
# Higher precedence for lower component type
if comp_a.component_type < comp_b.component_type:
return A_HAS_PRECEDENCE
if comp_a.component_type > comp_b.component_type:
return B_HAS_PRECEDENCE
# component types are equal -> type specific type-specific comparison
if comp_a.component_type in (IP_DESTINATION, IP_SOURCE):
if comp_a.offset < comp_b.offset:
return A_HAS_PRECEDENCE
if comp_a.offset > comp_b.offset:
return B_HAS_PRECEDENCE
# both components have the same offset
# assuming comp_a.value, comp_b.value of type
# ipaddress.IPv6Network
# and the offset bits are reset to 0 (since they are
# not represented in the NLRI)
if comp_a.value.overlaps(comp_b.value):
# longest prefixlen has precedence
if comp_a.value.prefixlen > \
comp_b.value.prefixlen:
return A_HAS_PRECEDENCE
if comp_a.value.prefixlen < \
comp_b.value.prefixlen:
return B_HAS_PRECEDENCE
# components equal -> continue with next
# component
elif comp_a.value > comp_b.value:
return B_HAS_PRECEDENCE
elif comp_a.value < comp_b.value:
return A_HAS_PRECEDENCE
else:
# assuming comp_a.value, comp_b.value of type
# bytearray
if len(comp_a.value) == len(comp_b.value):
if comp_a.value > comp_b.value:
return B_HAS_PRECEDENCE
if comp_a.value < comp_b.value:
return A_HAS_PRECEDENCE
# components equal -> continue with next
# component
else:
common = min(len(comp_a.value),
len(comp_b.value))
if comp_a.value[:common] > \
comp_b.value[:common]:
return B_HAS_PRECEDENCE
elif comp_a.value[:common] < \
comp_b.value[:common]:
return A_HAS_PRECEDENCE
# the first common bytes match
elif len(comp_a.value) > len(comp_b.value):
return A_HAS_PRECEDENCE
else:
return B_HAS_PRECEDENCE
return EQUAL
<CODE ENDS>
Acknowledgments
The authors would like to thank Pedro Marques, Hannes Gredler, Bruno
Rijsman, Brian Carpenter, and Thomas Mangin for their valuable input.
Contributors
Danny McPherson
Verisign, Inc.
Email: dmcpherson@verisign.com
Burjiz Pithawala
Individual
Email: burjizp@gmail.com
Andy Karch
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
United States of America
Email: akarch@cisco.com
Authors' Addresses
Christoph Loibl (editor)
next layer Telekom GmbH
Mariahilfer Guertel 37/7
Vienna
1150
AT Vienna
Austria
Phone: +43 664 1176414
Email: cl@tix.at
Robert Raszuk (editor)
Bloomberg LP
731 Lexington Ave
New York City, NY 10022
USA
NTT Network Innovations
940 Stewart Dr
Sunnyvale, CA 94085
United States of America
Email: robert@raszuk.net
Susan Hares (editor)
Huawei
7453 Hickory Hill
Saline, MI 48176
USA
United States of America
Email: shares@ndzh.com