Network Working Group H. Wang
Internet-Draft Huawei
Intended status: Standards Track A. Wang
Expires: May 7, 2020 China Telecom
S. Zhuang
Huawei
November 04, 2019
Destination-IP-Origin-AS Filter for BGP Flow Specification
draft-wang-idr-flowspec-dip-origin-as-filter-00
Abstract
This document specifies a new BGP-FS component type to support AS-
level filtering. The match field is the origin AS number of the
destination IP address that is encoded in the Flowspec NLRI.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Internet-Drafts are draft documents valid for a maximum of six months
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This Internet-Draft will expire on May 7, 2020.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definitions and Acronyms . . . . . . . . . . . . . . . . . . 2
3. The Flow Specification Encoding for Destination-Origin-AS
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Use Case . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 6
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6
1. Introduction
BGP Flow Specification (BGP-FS) [RFC5575] defines a new BGP NLRI to
distribute traffic flow specification rules via BGP ([RFC4271]).
BGP-FS policies have a match condition that may be n-tuple match in a
policy, and an action that modifies the packet and forwards/drops the
packet. Via BGP, new filter rules can be sent to all BGP peers
simultaneously without changing router configuration, and the BGP
peer can install these routes in the forwarding table. BGP-FS
defines Network Layer Reachability Information (NLRI) format used to
distribute traffic flow specification rules. NLRI (AFI=1, SAFI=133)
is for IPv4 unicast filtering. NLRI (AFI=1, SAFI=134) is for BGP/
MPLS VPN filtering.[I-D.ietf-idr-flowspec-l2vpn][I-D.ietf-idr-
flowspec-l2vpn] extends the flow-spec rules for layer 2 Ethernet
packets.
This document specifies a new BGP-FS component type to support AS-
level filtering. The match field is the origin AS number of the
destination IP address that is encoded in the Flowspec NLRI.
2. Definitions and Acronyms
o FS: Flow Specification
o Destination-Origin-AS: The origin AS number of the destination IP
address
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3. The Flow Specification Encoding for Destination-Origin-AS Filter
This document proposes a new flow specification rule that is encoded
in the NLRI. The following new component type is defined.
o Destination-IP-Origin-AS
Type TBD1 - Destination-Origin-AS
Encoding: <type (1 octet), [op, value]+>
Contains a set of {operator, value} pairs that are used to match the
Destination-IP-Origin-AS (i.e. the origin AS number of the
destination IP address).
The operator byte is encoded as:
0 1 2 3 4 5 6 7
+---+---+---+---+---+---+---+---+
| e | a | len | 0 |lt |gt |eq |
+---+---+---+---+---+---+---+---+
Where:
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
current one. If set, the operation is a logical AND. It MUST be
unset in the Destination-Origin-AS filter.
lt - less than comparison between data and value.
gt - greater than comparison between data and value.
eq - equality between data and value.
The bits lt, gt, and eq can be combined to produce match the
Destination-Origin-AS filter or a range of Destination-IP-Origin-AS
filter(e.g. less than AS1 and greater than AS2).
The value field is encoded as:
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
+---------------------------------------------------------------+
~ Destination-IP-Origin-AS (4 octets) ~
+---------------------------------------------------------------+
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4. Use Case
In AS64597's R1, if the ISP AS64597 wants to redirect all packets
from IP Prefix 61 to AS64598, first goto to R3, then forward to
AS64598", the ISP can use the traditional method or the method
defining in this draft.
+---------+
| BGP FS |
| Server |
+----|----+
|
|
/
/
************/************ IP Prefix 81
* / * IP Prefix 82
IP Prefix 61 * / AS64597 * IP Prefix 83
* / * IP Prefix 84
+-------+ * +---+/ +---+ * +-------+
+AS64596+-------+ R1+---------+ R2|------+AS64598+
+-------+ * +-+-+\ +---+ */ +-------+
* \ |\ /
* \ | \ /* IP Prefix 91
* \ | /\* IP Prefix 92
* \ | / \ IP Prefix 93
* \ |/ *\ IP Prefix 94
* \ +-+-+ * \ +-------+
* \-+ R3+------+AS64599+
* +---+ * +-------+
* *
*************************
Figure 1: Steering the Traffic Using Flowspec
Using the traditional method, the ISP AS64597 needs to setup multiple
"Destination Prefix + Source Prefix" rules in Router R1 as following:
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+--------------+--------------+-------------------------+
| Destination | Source Prefix| Redirect to IP Nexthop |
| Prefix | | |
+--------------+--------------+-------------------------+
| IP Prefix 81 | IP Prefix 61 | R3 |
+--------------+--------------+-------------------------+
| IP Prefix 82 | IP Prefix 61 | R3 |
+--------------+--------------+-------------------------+
| IP Prefix 83 | IP Prefix 61 | R3 |
+--------------+--------------+-------------------------+
| IP Prefix 84 | IP Prefix 61 | R3 |
+--------------+--------------+-------------------------+
| More... |
+--------------+--------------+-------------------------+
Figure 2: Steering the Traffic Using Destination Prefix and Source Prefix
Using the method defining in this draft, the ISP AS64597 needs to
setup only one "Destination Origin AS + Source Prefix" rule in Router
R1 as following:
+--------------+--------------+-------------------------+
| Destination | Source Prefix| Redirect to IP Nexthop |
| IP Origin AS | | |
+--------------+--------------+-------------------------+
| 64598 | IP Prefix 61 | R3 |
+--------------+--------------+-------------------------+
Figure 3: Steering the Traffic Using Origin AS and Source Prefix
5. Security Considerations
No new security issues are introduced to the BGP protocol by this
specification.
6. IANA
IANA is requested to a new entry in "Flow Spec component types
registry" with the following values:
+----------------------------------------------------------+
| Type | RFC or Draft | Description |
+----------------------------------------------------------+
| TBD1 | This Draft | Destination-IP-Origin-AS |
+----------------------------------------------------------+
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7. Contributors
TBD
8. Acknowledgments
The authors would like to acknowledge the review and inputs from Gang
Yan, Zhenbin Li, Rainbow Wu and Ziqing Cao.
9. References
[I-D.ietf-idr-flowspec-l2vpn]
Weiguo, H., Eastlake, D., Uttaro, J., Litkowski, S., and
S. Zhuang, "BGP Dissemination of L2VPN Flow Specification
Rules", draft-ietf-idr-flowspec-l2vpn-11 (work in
progress), July 2019.
[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-17 (work in progress), June
2019.
[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>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<https://www.rfc-editor.org/info/rfc5575>.
Authors' Addresses
Haibo Wang
Huawei
156 Beiqing Road
Beijing 100095
P.R. China
Email: rainsword.wang@huawei.com
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Aijun
China Telecom
Beiqijia Town, Changping District
Beijing 102209
P.R. China
Email: wangaj3@chinatelecom.cn
Shunwan Zhuang
Huawei
156 Beiqing Road
Beijing 100095
P.R. China
Email: zhuangshunwan@huawei.com
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