Internet DRAFT - draft-jiang-idr-ts-flowspec-srv6-policy
draft-jiang-idr-ts-flowspec-srv6-policy
Network Working Group W. Jiang
Internet-Draft Y. Liu
Intended status: Informational China Mobile
Expires: September 24, 2022 S. Chen
S. Zhuang
Huawei
March 23, 2022
Traffic Steering using BGP Flowspec with SRv6 Policy
draft-jiang-idr-ts-flowspec-srv6-policy-07
Abstract
BGP Flow Specification (FlowSpec) [RFC8955] [RFC8956] has been
proposed to distribute BGP FlowSpec NLRI to FlowSpec clients to
mitigate (distributed) denial-of-service attacks, and to provide
traffic filtering in the context of a BGP/MPLS VPN service.
Recently, traffic steering applications in the context of SRv6 using
FlowSpec aslo attract attention. This document introduces the usage
of BGP FlowSpec to steer packets into an SRv6 Policy.
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 RFC 2119 [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
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 24, 2022.
Jiang, et al. Expires September 24, 2022 [Page 1]
Internet-Draft FlowSpec with SRv6 Policy March 2022
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definitions and Acronyms . . . . . . . . . . . . . . . . . . 3
3. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Application Example . . . . . . . . . . . . . . . . . . . . . 4
5. Running Code . . . . . . . . . . . . . . . . . . . . . . . . 7
5.1. Interop-test Status . . . . . . . . . . . . . . . . . . . 7
5.2. Deployment Status . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
10.1. Normative References . . . . . . . . . . . . . . . . . . 8
10.2. Informative References . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction
Segment Routing IPv6 (SRv6) is a protocol designed to forward IPv6
data packets on a network using the source routing model. SRv6
enables the ingress to add a segment routing header (SRH) [RFC8754]
to an IPv6 packet and push an explicit IPv6 address stack into the
SRH. After receiving the packet, each transit node updates the IPv6
destination IP address in the packet and segment list to implement
hop-by-hop forwarding.
SRv6 Policy [I-D.ietf-spring-segment-routing-policy] is a tunneling
technology developed based on SRv6. An SRv6 Policy is a set of
candidate paths consisting of one or more segment lists, that is,
segment ID (SID) lists. Each SID list identifies an end-to-end path
from the source to the destination, instructing a device to forward
Jiang, et al. Expires September 24, 2022 [Page 2]
Internet-Draft FlowSpec with SRv6 Policy March 2022
traffic through the path rather than the shortest path computed using
an IGP. The header of a packet steered into an SRv6 Policy is
augmented with an ordered list of segments associated with that SRv6
Policy, so that other devices on the network can execute the
instructions encapsulated into the list.
The headend of an SRv6 Policy may learn multiple candidate paths for
an SRv6 Policy. Candidate paths may be learned via a number of
different mechanisms, e.g., CLI, NetConf, PCEP, or BGP.
[RFC8955] [RFC8956] defines the flow specification (FlowSpec) that
allows to convey flow specifications and traffic Action/Rules
associated (rate- limiting, redirect, remark ...). BGP Flow
specifications are encoded within the MP_REACH_NLRI and
MP_UNREACH_NLRI attributes. Rules (Actions associated) are encoded
in Extended Community attribute. The BGP Flow Specification function
allows BGP Flow Specification routes that carry traffic policies to
be transmitted to BGP Flow Specification peers to steer traffic.
This document proposes BGP flow specification usage that are used to
steer data flow into an SRv6 Policy as well as to indicate Tailend
function.
2. Definitions and Acronyms
o FlowSpec: Flow Specification
o SR: Segment Routing
o SRv6: IPv6 Segment Routing
o SID: Segment Identifier
o SRH: Segment Routing Header
o TE: Traffic Engineering
3. Operations
An SRv6 Policy [I-D.ietf-spring-segment-routing-policy] is identified
through the tuple <headend, color, endpoint>. In the context of a
specific headend, one may identify an SRv6 policy by the <color,
endpoint> tuple. The headend is the node where the SRv6 policy is
instantiated/implemented. The headend is specified as an IPv4 or
IPv6 address and is expected to be unique in the domain. The
endpoint indicates the destination of the SRv6 policy. The endpoint
is specified as an IPv6 address and is expected to be unique in the
domain. The color is a 32-bit numerical value that associates the
Jiang, et al. Expires September 24, 2022 [Page 3]
Internet-Draft FlowSpec with SRv6 Policy March 2022
SRv6 Policy, and it defines an application-level network Service
Level Agreement (SLA) policy.
Assume one or multiple SRv6 Policies are already setup in the SRv6
HeadEnd device. In order to steer traffic into a specific SRv6
policy at the Headend, one can use the SRv6 color extended community
and endpoint to map to a satisfying SRv6 policy, and steer traffic
into this specific policy.
[I-D.ietf-idr-flowspec-redirect-ip] defines the redirect to IPv4 and
IPv6 Next-hop action. The IPv6 next-hop address in the Flow-spec
Redirect to IPv6 Extended Community can be used to specify the
endpoint of the SRv6 Policy. When the packets reach to the TailEnd
device, some specific function imformation identifiers can be used
decide how to further process the flows. Several endpoint functions
are already defined, e.g., End.DT6: Endpoint with decapsulation and
IPv6 table lookup, and End.DX6: Endpoint with decapsulation and IPv6
cross-connect. The BGP Prefix-SID defined in [RFC8669] is utilized
to enable SRv6 VPN services [I-D.ietf-bess-srv6-services]. SRv6
Services TLVs within the BGP Prefix-SID Attribute can be used to
indicate the endpoint functions.
This document proposes to carry the Color Extended Community and BGP
Prefix-SID Attribute in the context of a Flowspec NLRI [RFC8955]
[RFC8956] to an SRv6 Headend to steer traffic into one SRv6 policy,
as well as to indicate specific Tailend functions.
In this document, the usage of at most one Color Extended Community
in combination at most one BGP Prefix SID Attribute is discussed.
For the case that a flowspec route carries multiple Color Extend
Communities and/or a BGP Prefix SID Attribute, a protocol extension
to Flowspec is required, and is thus out of the scope of this
document.
However, the method proposed in this document still supports load
balancing to the tailend device. To achieve that, the headend device
CAN set up multiple paths in one SRv6 policy, and use a Flowspec
route to indicate the specific SRv6 policy.
4. Application Example
In following scenario, BGP FlowSpec Controller signals the filter
rules, the redirect action, the policy color and the function
imformation (SRv6 SID: Service_id_x) to the HeadEnd device.
Jiang, et al. Expires September 24, 2022 [Page 4]
Internet-Draft FlowSpec with SRv6 Policy March 2022
+------------+
| BGP FS |
| Controller |
+------------+
| Flowspec route to HeadEnd:
| NLRI: Filter Rules
| Redirect to IPv6 Nexthop: TailEnd's Address
| Policy Color: C1
| PrefixSID: Service_id_x
| .-----.
| ( )
V .--( )--.
+-------+ ( ) +-------+
| |_( SRv6 Core Network )_| |
|HeadEnd| ( ================> ) |TailEnd|
+-------+ (SR List<S1,S2,S3>) +-------+
'--( )--' Service SID: Service_id_x
( ) (e.g.: End.DT4 or End.DT6 or others)
'-----'
Figure 1: Steering the Flow into SRv6 Policy (Option 1)
When the HeadEnd device (as a Flowspec client) receives such
instructions, it will steer the flows matching the criteria in the
Flowspec route into the SRv6 Policy matching the tuple (Endpoint:
TailEnd's Address, Color: C1). And the packets of such flows will be
encapsulated with SRH using the SR List<S1, S2, S3, Service_id_x>.
When the packets reach to the TailEnd device, they will be further
procetssed per the function denoted by the Service_id_x.
When the HeadEnd device determines (with the help of SRv6 SID
Structure) that the Service SID belongs to the same SRv6 Locator as
the last SRv6 SID of the TailEnd device in the SRv6 Policy segment
list, it MAY exclude that last SRv6 SID when steering the service
flow. For example, the effective segment list of the SRv6 Policy
associated with SID list <S1, S2, S3> would be <S1, S2,
Service_id_x>.
If the last SRv6 SID (For example, S3 we use here) of the TailEnd
device in the SRv6 Policy segment list is USD-flavored, an SRv6
Service SID (e.g., End.DT4 or End.DT6) is not required when BGP
FlowSpec Controller send the FlowSpec route to the HeadEnd device (as
a Flowspec client).
Jiang, et al. Expires September 24, 2022 [Page 5]
Internet-Draft FlowSpec with SRv6 Policy March 2022
+------------+
| BGP FS |
| Controller |
+------------+
| Flowspec route to HeadEnd:
| NLRI: Filter Rules
| Redirect to IPv6 Nexthop: TailEnd's Address
| Policy Color: C2
| .-----.
| ( )
V .--( )--.
+-------+ ( ) +-------+
| |_( SRv6 Core Network )_| |
|HeadEnd| ( ================> ) |TailEnd|
+-------+ (SR List<S1,S2,S3>) +-------+
'--( )--'
( )
'-----'
Note: S3 MUST be a USD-flavored SRv6 SID of the TailEnd
Figure 2: Steering the Flow into SRv6 Policy (Option 2)
When the HeadEnd device (as a Flowspec client) receives such
instructions, it will steer the flows matching the criteria in the
Flowspec route into the SRv6 Policy matching the tuple (Endpoint:
TailEnd's Address, Color: C2). And the packets of such flows will be
encapsulated with SRH using the SR List<S1, S2, S3>. When the
packets reach to the TailEnd device, they will be further procetssed
per the function denoted by the USD-flavored SRv6 SID S3.
At this point, the work discusses the matching of global routing
table prefixes.
For the cases of intra-AS and inter-AS traffic steering using this
method, the usages of Flowspec Color Extended Community with BGP
prefix SID are the same for both scenarios. The difference lie
between the local SRv6 policy configurations. For the inter-domain
case, the operator can configure an inter-domain SRv6 policy/path at
the Headend device. For the intra-domain case, the operator can
configure an intra-domain SRv6 policy/path at the Headend device.
.
Jiang, et al. Expires September 24, 2022 [Page 6]
Internet-Draft FlowSpec with SRv6 Policy March 2022
5. Running Code
5.1. Interop-test Status
The Traffic Steering using BGP Flowspec with SRv6 Policy mechanism
has been implemented on the following hardware devices, software
implementations and SDN controllers. They had also successfully
participated in the series of joint interoperability testing events
hosted by China Mobile from July 2021 to October 2021. The following
hardware devices and software implementations had successfully passed
the interoperability testing (in alphabetical order).
Routers:
-----------------------------------------------------------
| Vendors | Device Model | Version |
-----------------------------------------------------------
| Huawei | NE40-X8A | NE40E V800R021C00SPC091T |
-----------------------------------------------------------
| New H3C | CR16010H-FA | Version 7.1.075, ESS 8305 |
-----------------------------------------------------------
| Ruijie | RG-N8010-R | N8000-R_RGOS 12.8(1)B08T1 |
-----------------------------------------------------------
| ZTE | M6000-8S Plus | V5.00.10(5.60.5) |
-----------------------------------------------------------
Controllers:
-----------------------------------------------------------
| Vendors | Device Model | Version |
-----------------------------------------------------------
| China Unitecs | I-T-E SC | V1.3.6P3 |
-----------------------------------------------------------
| Huawei | NCE-IP | V100R021C00 |
-----------------------------------------------------------
| Ruijie | RG-ONC-AIO-H | RG-ION-WAN-CLOUD_2.00T1 |
-----------------------------------------------------------
| ZTE | ZENIC ONE | R22V16.21.20 |
-----------------------------------------------------------
5.2. Deployment Status
TBD
6. IANA Considerations
No IANA actions are required for this document.
Jiang, et al. Expires September 24, 2022 [Page 7]
Internet-Draft FlowSpec with SRv6 Policy March 2022
7. Security Considerations
This document does not change the security properties of SRv6 and
BGP.
8. Contributors
The following people made significant contributions to this document:
Yunan Gu
Huawei
Email: guyunan@huawei.com
Haibo Wang
Huawei
Email: rainsword.wang@huawei.com
Jie Dong
Huawei
Email: jie.dong@huawei.com
Xue Yang
China Mobile
Email: yangxuewl@chinamobile.com
9. Acknowledgements
The authors would like to acknowledge the review and inputs from
Jeffrey Haas, Kaliraj Vairavakkalai, Robin Li, Acee Lindem, Gunter
Van De Velde, John Scudder, Rainbow Wu and Gang Yang.
10. References
10.1. Normative References
[I-D.ietf-bess-srv6-services]
Dawra, G., Talaulikar, K., Raszuk, R., Decraene, B.,
Zhuang, S., and J. Rabadan, "SRv6 BGP based Overlay
Services", draft-ietf-bess-srv6-services-15 (work in
progress), March 2022.
[I-D.ietf-idr-flowspec-redirect-ip]
Uttaro, J., Haas, J., Texier, M., Karch, A., Ray, S.,
Simpson, A., and W. Henderickx, "BGP Flow-Spec Redirect to
IP Action", draft-ietf-idr-flowspec-redirect-ip-02 (work
in progress), February 2015.
Jiang, et al. Expires September 24, 2022 [Page 8]
Internet-Draft FlowSpec with SRv6 Policy March 2022
[I-D.ietf-idr-segment-routing-te-policy]
Previdi, S., Filsfils, C., Talaulikar, K., Mattes, P.,
Jain, D., and S. Lin, "Advertising Segment Routing
Policies in BGP", draft-ietf-idr-segment-routing-te-
policy-16 (work in progress), March 2022.
[I-D.ietf-idr-tunnel-encaps]
Patel, K., Velde, G. V. D., Sangli, S. R., and J. Scudder,
"The BGP Tunnel Encapsulation Attribute", draft-ietf-idr-
tunnel-encaps-22 (work in progress), January 2021.
[I-D.ietf-spring-segment-routing-policy]
Filsfils, C., Talaulikar, K., Voyer, D., Bogdanov, A., and
P. Mattes, "Segment Routing Policy Architecture", draft-
ietf-spring-segment-routing-policy-22 (work in progress),
March 2022.
[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>.
[RFC8669] Previdi, S., Filsfils, C., Lindem, A., Ed., Sreekantiah,
A., and H. Gredler, "Segment Routing Prefix Segment
Identifier Extensions for BGP", RFC 8669,
DOI 10.17487/RFC8669, December 2019,
<https://www.rfc-editor.org/info/rfc8669>.
[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>.
[RFC8956] Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed.,
"Dissemination of Flow Specification Rules for IPv6",
RFC 8956, DOI 10.17487/RFC8956, December 2020,
<https://www.rfc-editor.org/info/rfc8956>.
10.2. Informative References
[RFC4456] Bates, T., Chen, E., and R. Chandra, "BGP Route
Reflection: An Alternative to Full Mesh Internal BGP
(IBGP)", RFC 4456, DOI 10.17487/RFC4456, April 2006,
<https://www.rfc-editor.org/info/rfc4456>.
Jiang, et al. Expires September 24, 2022 [Page 9]
Internet-Draft FlowSpec with SRv6 Policy March 2022
[RFC8754] Filsfils, C., Ed., Dukes, D., Ed., Previdi, S., Leddy, J.,
Matsushima, S., and D. Voyer, "IPv6 Segment Routing Header
(SRH)", RFC 8754, DOI 10.17487/RFC8754, March 2020,
<https://www.rfc-editor.org/info/rfc8754>.
Authors' Addresses
Wenying Jiang
China Mobile
Beijing
China
Email: jiangwenying@chinamobile.com
Yisong Liu
China Mobile
Beijing
China
Email: liuyisong@chinamobile.com
Shuanglong Chen
Huawei
Beijing
China
Email: chenshuanglong@huawei.com
Shunwan Zhuang
Huawei
Beijing
China
Email: zhuangshunwan@huawei.com
Jiang, et al. Expires September 24, 2022 [Page 10]
