Internet DRAFT - draft-keyupate-idr-bgp-prefix-sid
draft-keyupate-idr-bgp-prefix-sid
IDR K. Patel
Internet-Draft S. Previdi
Intended status: Standards Track C. Filsfils
Expires: January 21, 2016 A. Sreekantiah
Cisco Systems
S. Ray
Unaffiliated
H. Gredler
Juniper Networks
July 20, 2015
Segment Routing Prefix SID extensions for BGP
draft-keyupate-idr-bgp-prefix-sid-05
Abstract
Segment Routing (SR) architecture allows a node to steer a packet
flow through any topological path and service chain by leveraging
source routing. The ingress node prepends a SR header to a packet
containing a set of "segments". Each segment represents a
topological or a service-based instruction. Per-flow state is
maintained only at the ingress node of the SR domain.
This document describes the BGP extension for announcing BGP Prefix
Segment Identifier (BGP Prefix SID) information.
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]
only when they appear in all upper case. They may also appear in
lower or mixed case as English words, without any normative meaning.
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 http://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
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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 January 21, 2016.
Copyright Notice
Copyright (c) 2015 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
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Segment Routing Documents . . . . . . . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. BGP-Prefix-SID . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. MPLS Prefix Segment . . . . . . . . . . . . . . . . . . . 4
3.2. IPv6 Prefix Segment . . . . . . . . . . . . . . . . . . . 5
4. BGP-Prefix-SID Attribute . . . . . . . . . . . . . . . . . . 5
4.1. Label-Index TLV . . . . . . . . . . . . . . . . . . . . . 6
4.2. IPv6 SID . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3. Originator SRGB TLV . . . . . . . . . . . . . . . . . . . 7
5. Receiving BGP-Prefix-SID Attribute . . . . . . . . . . . . . 9
5.1. MPLS Dataplane: Labeled Unicast . . . . . . . . . . . . . 9
5.2. IPv6 Dataplane . . . . . . . . . . . . . . . . . . . . . 10
6. Announcing BGP-Prefix-SID Attribute . . . . . . . . . . . . . 10
6.1. MPLS Dataplane: Labeled Unicast . . . . . . . . . . . . . 10
6.2. IPv6 Dataplane . . . . . . . . . . . . . . . . . . . . . 11
7. Error Handling of BGP-Prefix-SID Attribute . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
11. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 12
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
12.1. Normative References . . . . . . . . . . . . . . . . . . 12
12.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
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1. Segment Routing Documents
The main references for this document are the SR architecture defined
in [I-D.ietf-spring-segment-routing] and the related use case
illustrated in [I-D.filsfils-spring-segment-routing-msdc].
The Segment Routing Egress Peer Engineering architecture is described
in [I-D.filsfils-spring-segment-routing-central-epe].
The Segment Routing Egress Peer Engineering BGPLS extensions are
described in [I-D.ietf-idr-bgpls-segment-routing-epe].
2. Introduction
Segment Routing (SR) architecture leverages the source routing
paradigm. A group of inter-connected nodes that use SR forms a SR
domain. The ingress node of the SR domain prepends a SR header
containing "segments" to an incoming packet. Each segment represents
a topological instruction such as "go to prefix P following shortest
path" or a service instruction (e.g.: "pass through deep packet
inspection"). By inserting the desired sequence of instructions, the
ingress node is able to steer a packet via any topological path and/
or service chain; per-flow state is maintained only at the ingress
node of the SR domain.
Each segment is identified by a Segment Identifier (SID). As
described in [I-D.ietf-spring-segment-routing], when SR is applied to
the MPLS dataplane the SID consists of a label while when SR is
applied to the IPv6 dataplane the SID consists of an IPv6 prefix (see
[I-D.previdi-6man-segment-routing-header]).
A BGP-Prefix Segment (aka BGP-Prefix-SID), is a BGP segment attached
to a BGP prefix. A BGP-Prefix-SID is always global within the SR/BGP
domain and identifies an instruction to forward the packet over the
ECMP-aware best-path computed by BGP to the related prefix. The BGP-
Prefix-SID is the identifier of the BGP prefix segment.
This document describes the BGP extension to signal the BGP-Prefix-
SID. Specifically, this document defines a new BGP attribute known
as the BGP Prefix SID attribute and specifies the rules to originate,
receive and handle error conditions of the new attribute.
As described in [I-D.filsfils-spring-segment-routing-msdc], the newly
proposed BGP Prefix-SID attribute can be attached to prefixes from
AFI/SAFI:
Multiprotocol BGP labeled IPv4/IPv6 Unicast ([RFC3107]).
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Multiprotocol BGP ([RFC4760]) unlabeled IPv6 Unicast.
[I-D.filsfils-spring-segment-routing-msdc] describes use cases where
the Prefix-SID is used for the above AFI/SAFI.
3. BGP-Prefix-SID
The BGP-Prefix-SID attached to a BGP prefix P represents the
instruction "go to Prefix P" along its BGP bestpath (potentially
ECMP-enabled).
3.1. MPLS Prefix Segment
The BGP Prefix Segment is realized on the MPLS dataplane in the
following way:
According to [I-D.ietf-spring-segment-routing], each BGP speaker
is configured with a label block called the Segment Routing Global
Block (SRGB). The SRGB of a node is a local property and could be
different on different speakers.
As described in [I-D.filsfils-spring-segment-routing-msdc] the
operator assigns a globally unique "index", L_I, to a locally
sourced prefix of a BGP speaker N which is advertised to all other
BGP speakers in the SR domain.
The index L_I is a 32 bit offset in the SRGB. Each BGP speaker
derives its local MPLS label, L, by adding L_I to the start value
of its own SRGB, and programs L in its MPLS dataplane as its
incoming/local label for the prefix.
If the BGP speakers are configured with the same SRGB start value,
they will all program the same MPLS label for a given prefix P.
This has the effect of having a single label for prefix P across
all BGP speakers despite that the MPLS paradigm of "local label"
is preserved and this clearly simplifies the deployment and
operations of traffic engineering in BGP driven networks, as
described in [I-D.filsfils-spring-segment-routing-msdc].
If the BGP speakers cannot be configured with the same SRGB, the
proposed BGP Prefix-SID attribute allows the advertisement of the
SRGB so each node can advertise the SRGB it's configured with. The
drawbacks of the use case where BGP speakers have different SRGBs are
documented in [I-D.filsfils-spring-segment-routing-msdc].
In order to advertise the label index of a given prefix P and,
optionally, the SRGB, a new extension to BGP is needed: the BGP
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Prefix SID attribute. This extension is described in subsequent
sections.
3.2. IPv6 Prefix Segment
As defined in [I-D.previdi-6man-segment-routing-header], in SR for
the IPv6 dataplane, the SRGB consists of the set of IPv6 addresses
used within the SR domain (as described in
[I-D.previdi-6man-segment-routing-header]). Therefore the BGP
speaker willing to process SR IPv6 packets MUST advertise an IPv6
prefix with the attached Prefix SID attribute and related SR IPv6
flag (see subsequent section).
As described in [I-D.filsfils-spring-segment-routing-msdc], when SR
is used over an IPv6 dataplane, the BGP Prefix Segment is
instantiated by an IPv6 prefix originated by the BGP speaker.
Each node advertises a globally unique IPv6 address representing
itself in the domain. This prefix (e.g.: its loopback interface
address) is advertised to all other BGP speakers in the SR domain.
Also, each node MUST advertise its support of Segment Routing for
IPv6 dataplane. This is realized using the Prefix SID Attribute
defined below.
4. BGP-Prefix-SID Attribute
The BGP Prefix SID attribute is an optional, transitive BGP path
attribute. The attribute type code is to be assigned by IANA
(suggested value: 40). The value field of the BGP-Prefix-SID
attribute has the following format:
The value field of the BGP Prefix SID attribute is defined here to be
a set of elements encoded as "Type/Length/Value" (i.e., a set of
TLVs). Following TLVs are defined:
o Label-Index TLV
o IPv6 SID TLV
o Originator SRGB TLV
Label-Index and Originator SRGB TLVs are used only when SR is applied
to the MPLS dataplane.
IPv6 SID TLV is used only when SR is applied to the IPv6 dataplane.
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4.1. Label-Index TLV
The Label-Index TLV MUST be present in the Prefix-SID attribute
attached to Labeled IPv4/IPv6 unicast prefixes ([RFC3107]) and has
the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Label Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Label Index |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
o Type is 1.
o Length: is 7, the total length of the value portion of the TLV.
o RESERVED: 8 bit field. SHOULD be 0 on transmission and MUST be
ignored on reception.
o Flags: 16 bits of flags. None are defined at this stage of the
document. The flag field SHOULD be clear on transmission and MUST
be ignored at reception.
o Label Index: 32 bit value representing the index value in the SRGB
space.
4.2. IPv6 SID
The Label-Index TLV MUST be present in the Prefix-SID attribute
attached to MP-BGP unlabeled IPv6 unicast prefixes ([RFC4760]) and
has the following format:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
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o Type is 2.
o Length: is 3, the total length of the value portion of the TLV.
o RESERVED: 8 bit field. SHOULD be 0 on transmission and MUST be
ignored on reception.
o Flags: 16 bits of flags defined as follow:
0 1
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|S| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
* S flag: if set then it means that the BGP speaker attaching the
Prefix-SID Attribute to a prefix is capable of processing the
IPv6 Segment Routing Header (SRH,
[I-D.previdi-6man-segment-routing-header]) for the segment
corresponding to the originated IPv6 prefix. The use case
leveraging the S flag is described in
[I-D.filsfils-spring-segment-routing-msdc].
The other bits of the flag field SHOULD be clear on transmission
an MUST be ignored at reception.
4.3. Originator SRGB TLV
The Originator SRGB TLV is an optional TLV and has the following
format:
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0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Flags |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags |
+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SRGB 1 (6 octets) |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SRGB n (6 octets) |
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
where:
o Type is 3.
o Length is the total length of the value portion of the TLV: 2 +
multiple of 6.
o Flags: 16 bits of flags. None are defined in this document.
Flags SHOULD be clear on transmission an MUST be ignored at
reception.
o SRGB: 3 octets of base followed by 3 octets of range. Note that
SRGB field MAY appear multiple times.
The Originator SRGB TLV contains the SRGB of the router originating
the prefix to which the BGP Prefix SID is attached and MUST be kept
in the Prefix-SID Attribute unchanged during the propagation of the
BGP update.
The originator SRGB describes the SRGB of the node where the BGP
Prefix Segment end. It is used to build SRTE policies when different
SRGB's are used in the fabric
([I-D.filsfils-spring-segment-routing-msdc]).
The originator SRGB may only appear on Prefix-SID attribute attached
to prefixes of SAFI 4 (labeled unicast, [RFC3107]).
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5. Receiving BGP-Prefix-SID Attribute
A BGP speaker receiving a BGP Prefix-SID attribute from an EBGP
neighbor residing outside the boundaries of the SR domain, SHOULD
discard the attribute unless it is configured to accept the attribute
from the EBGP neighbor. A BGP speaker MAY log an error for further
analysis when discarding an attribute.
5.1. MPLS Dataplane: Labeled Unicast
The Prefix-SID attribute MUST contain the Label-Index TLV and MAY
contain the Originator SRGB. A BGP Prefix-SID attribute received
without a Label-Index TLV MUST be considered as "unacceptable" by the
receiving speaker.
A BGP speaker may be locally configured with an SRGB=[GB_S, GB_E].
The preferred method for deriving the SRGB is a matter of local
router configuration.
Given a label index L_I, we call L = L_I + GB_S as the derived label.
A BGP Prefix-SID attribute is called "unacceptable" for a speaker M
if the derived label value L lies outside the SRGB configured on M.
Otherwise the Label Index attribute is called "acceptable" to speaker
M.
The mechanisms through which a given label_index value is assigned to
a given prefix are outside the scope of this document. The label-
index value associated with a prefix is locally configured at the BGP
router originating the prefix.
The Prefix-SID attribute MUST contain the Label-Index TLV and MAY
contain the Originator SRGB TLV. A BGP Prefix-SID attribute received
without a Label-Index TLV MUST be considered as "unacceptable" by the
receiving speaker.
When a BGP speaker receives a path from a neighbor with an acceptable
BGP Prefix-SID attribute, it SHOULD program the derived label as the
local label for the prefix in its MPLS dataplane. In case of any
error, a BGP speaker MUST resort to the error handling rules
specified in Section 7. A BGP speaker MAY log an error for further
analysis.
When a BGP speaker receives a path from a neighbor with an
unacceptable BGP Prefix-SID attribute, for the purpose of label
allocation, it SHOULD treat the path as if it came without a Prefix-
SID attribute. A BGP speaker MAY choose to assign a local (also
called dynamic) label (non-SRGB) for such a prefix. A BGP speaker
MAY log an error for further analysis.
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A BGP speaker receiving a prefix with a Prefix-SID attribute and a
label NLRI field of implicit-null from a neighbor MUST adhere to
standard behavior and program its MPLS dataplane to pop the top label
when forwarding traffic to the prefix. The label NLRI defines the
outbound label that MUST be used by the receiving node. The Label
Index gives a hint to the receiving node on which local/incoming
label the BGP speaker SHOULD use.
5.2. IPv6 Dataplane
When a SR IPv6 BGP speaker receives a IPv6 Unicast BGP Update with a
prefix having the BGP Prefix SID attribute attached, it checks
whether the IPv6 SID TLV is present and if the S-flag is set. If the
IPv6 SID TLV is not present or if the S-flag is not set, then the
Prefix-SID attribute MUST be considered as "unacceptable" by the
receiving speaker.
The Originator SRGB MUST be ignored on reception.
A BGP speaker receiving a BGP Prefix-SID attribute from an EBGP
neighbor residing outside the boundaries of the SR domain, SHOULD
discard the attribute unless it is configured to accept the attribute
from the EBGP neighbor. A BGP speaker MAY log an error for further
analysis when discarding an attribute.
6. Announcing BGP-Prefix-SID Attribute
The BGP Prefix-SID attribute MAY be attached to labeled BGP prefixes
(IPv4/IPv6) [RFC3107]or to IPv6 prefixes [RFC4760]. In order to
prevent distribution of the BGP Prefix-SID attribute beyond its
intended scope of applicability, attribute filtering MAY be deployed.
6.1. MPLS Dataplane: Labeled Unicast
A BGP speaker that originates a prefix attaches the Prefix-SID
attribute when it advertises the prefix to its neighbors. The value
of the Label-Index in the Label-Index TLV is determined by
configuration.
A BGP speaker that originates a Prefix-SID attribute MAY optionally
announce Originator SRGB TLV along with the mandatory Label-Index
TLV. The content of the Originator SRGB TLV is determined by the
configuration.
Since the Label-index value must be unique within an SR domain, by
default an implementation SHOULD NOT advertise the BGP Prefix-SID
attribute outside an Autonomous System unless it is explicitly
configured to do so.
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A BGP speaker that advertises a path received from one of its
neighbors SHOULD advertise the Prefix-SID received with the path
without modification regardless of whether the Prefix-SID was
acceptable. If the path did not come with a Prefix-SID attribute,
the speaker MAY attach a Prefix-SID to the path if configured to do
so. The content of the TLVs present in the Prefix-SID is determined
by the configuration.
In all cases, the label field of the NLRI ([RFC3107], [RFC4364]) MUST
be set to the local/incoming label programmed in the MPLS dataplane
for the given prefix. If the prefix is associated with one of the
BGP speakers interfaces, this label is the usual MPLS label (such as
the implicit or explicit NULL label).
6.2. IPv6 Dataplane
A BGP speaker that originates a prefix attaches the Prefix-SID
attribute when it advertises the prefix to its neighbors. The IPv6
SID TLV MUST be present and the S-flag MUST be set.
A BGP speaker that advertises a path received from one of its
neighbors SHOULD advertise the Prefix-SID received with the path
without modification regardless of whether the Prefix-SID was
acceptable. If the path did not come with a Prefix-SID attribute,
the speaker MAY attach a Prefix-SID to the path if configured to do
so. The IPv6-SID TLV MUST be present in the Prefix-SID and with the
S-flag set.
7. Error Handling of BGP-Prefix-SID Attribute
When a BGP Speaker receives a BGP Update message containing a
malformed BGP Prefix-SID attribute, it MUST ignore the received BGP
Prefix-SID attributes and not pass it to other BGP peers. This is
equivalent to the -attribute discard- action specified in
[I-D.ietf-idr-error-handling]. When discarding an attribute, a BGP
speaker MAY log an error for further analysis.
If the BGP Prefix-SID attribute appears more than once in an BGP
Update message message, then, according to
[I-D.ietf-idr-error-handling], all the occurrences of the attribute
other than the first one SHALL be discarded and the BGP Update
message shall continue to be processed.
When a BGP speaker receives an unacceptable Prefix-SID attribute, it
MAY log an error for further analysis.
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8. IANA Considerations
This document defines a new BGP path attribute known as the BGP
Prefix-SID attribute. This document requests IANA to assign a new
attribute code type (suggested value: 40) for BGP the Prefix-SID
attribute from the BGP Path Attributes registry.
This document defines two new TLVs for BGP Prefix-SID attribute.
These TLVs need to be registered with IANA. We request IANA to
create a new registry for BGP Prefix-SID Attribute TLVs as follows:
Under "Border Gateway Protocol (BGP) Parameters" registry, "BGP
Prefix SID attribute Types" Reference: draft-keyupate-idr-bgp-prefix-
side-05 Registration Procedure(s): Values 1-254 First Come, First
Served, Value 0 and 255 reserved
Value Type Reference
0 Reserved draft-keyupate-idr-bgp-prefix-side-05
1 Label-Index draft-keyupate-idr-bgp-prefix-side-05
2 IPv6 SID draft-keyupate-idr-bgp-prefix-side-05
3 Originator SRGB draft-keyupate-idr-bgp-prefix-side-05
4-254 Unassigned
255 Reserved draft-keyupate-idr-bgp-prefix-side-05
9. Security Considerations
This document introduces no new security considerations above and
beyond those already specified in [RFC4271] and [RFC3107].
10. Acknowledgements
The authors would like to thanks Satya Mohanty and Acee Lindem for
their contribution to this document.
11. Change Log
Initial Version: Sep 21 2014
12. References
12.1. Normative References
[I-D.ietf-idr-error-handling]
Chen, E., Scudder, J., Mohapatra, P., and K. Patel,
"Revised Error Handling for BGP UPDATE Messages", draft-
ietf-idr-error-handling-19 (work in progress), April 2015.
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[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3107] Rekhter, Y. and E. Rosen, "Carrying Label Information in
BGP-4", RFC 3107, DOI 10.17487/RFC3107, May 2001,
<http://www.rfc-editor.org/info/rfc3107>.
[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,
<http://www.rfc-editor.org/info/rfc4271>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <http://www.rfc-editor.org/info/rfc4364>.
12.2. Informative References
[I-D.filsfils-spring-segment-routing-central-epe]
Filsfils, C., Previdi, S., Patel, K., Aries, E.,
shaw@fb.com, s., Ginsburg, D., and D. Afanasiev, "Segment
Routing Centralized Egress Peer Engineering", draft-
filsfils-spring-segment-routing-central-epe-04 (work in
progress), July 2015.
[I-D.filsfils-spring-segment-routing-msdc]
Filsfils, C., Previdi, S., Mitchell, J., Aries, E.,
Lapukhov, P., Gaya, G., Afanasiev, D., Laberge, T.,
Nkposong, E., Nanduri, M., Uttaro, J., and S. Ray, "BGP-
Prefix Segment in large-scale data centers", draft-
filsfils-spring-segment-routing-msdc-02 (work in
progress), July 2015.
[I-D.ietf-idr-bgpls-segment-routing-epe]
Previdi, S., Filsfils, C., Ray, S., Patel, K., Dong, J.,
and M. Chen, "Segment Routing Egress Peer Engineering BGP-
LS Extensions", draft-ietf-idr-bgpls-segment-routing-
epe-00 (work in progress), June 2015.
[I-D.ietf-spring-segment-routing]
Filsfils, C., Previdi, S., Decraene, B., Litkowski, S.,
and R. Shakir, "Segment Routing Architecture", draft-ietf-
spring-segment-routing-03 (work in progress), May 2015.
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[I-D.previdi-6man-segment-routing-header]
Previdi, S., Filsfils, C., Field, B., and I. Leung, "IPv6
Segment Routing Header (SRH)", draft-previdi-6man-segment-
routing-header-06 (work in progress), May 2015.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<http://www.rfc-editor.org/info/rfc4760>.
Authors' Addresses
Keyur Patel
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95124 95134
USA
Email: keyupate@cisco.com
Stefano Previdi
Cisco Systems
Via Del Serafico, 200
Rome 00142
Italy
Email: sprevidi@cisco.com
Clarence Filsfils
Cisco Systems
Brussels
Belgium
Email: cfilsfils@cisco.com
Arjun Sreekantiah
Cisco Systems
170 W. Tasman Drive
San Jose, CA 95124 95134
USA
Email: asreekan@cisco.com
Patel, et al. Expires January 21, 2016 [Page 14]
Internet-Draft July 2015
Saikat Ray
Unaffiliated
Email: raysaikat@gmail.com
Hannes Gredler
Juniper Networks
Email: hannes@juniper.net
Patel, et al. Expires January 21, 2016 [Page 15]
