Diff: draft-ietf-ospf-segment-routing-extensions-15.txt - draft-ietf-ospf-segment-routing-extensions-16.txt

	< draft-ietf-ospf-segment-routing-extensions-15.txt	draft-ietf-ospf-segment-routing-extensions-16.txt >

	Open Shortest Path First IGP P. Psenak, Ed.	Open Shortest Path First IGP P. Psenak, Ed.
	Internet-Draft S. Previdi, Ed.	Internet-Draft S. Previdi, Ed.
	Intended status: Standards Track C. Filsfils	Intended status: Standards Track C. Filsfils

	Expires: November 23, 2017 Cisco Systems, Inc.	Expires: November 24, 2017 Cisco Systems, Inc.
	H. Gredler	H. Gredler
	RtBrick Inc.	RtBrick Inc.
	R. Shakir	R. Shakir
	Google, Inc.	Google, Inc.
	W. Henderickx	W. Henderickx
	Nokia	Nokia
	J. Tantsura	J. Tantsura
	Individual	Individual

	May 22, 2017	May 23, 2017

	OSPF Extensions for Segment Routing	OSPF Extensions for Segment Routing

	draft-ietf-ospf-segment-routing-extensions-15	draft-ietf-ospf-segment-routing-extensions-16

	Abstract	Abstract

	Segment Routing (SR) allows a flexible definition of end-to-end paths	Segment Routing (SR) allows a flexible definition of end-to-end paths
	within IGP topologies by encoding paths as sequences of topological	within IGP topologies by encoding paths as sequences of topological
	sub-paths, called "segments". These segments are advertised by the	sub-paths, called "segments". These segments are advertised by the
	link-state routing protocols (IS-IS and OSPF).	link-state routing protocols (IS-IS and OSPF).

	This draft describes the OSPF extensions required for Segment	This draft describes the OSPF extensions required for Segment
	Routing.	Routing.

	skipping to change at page 2, line 4 ¶	skipping to change at page 2, line 4 ¶

	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 http://datatracker.ietf.org/drafts/current/.	Drafts is at http://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 November 23, 2017.	This Internet-Draft will expire on November 24, 2017.

	Copyright Notice	Copyright Notice

	Copyright (c) 2017 IETF Trust and the persons identified as the	Copyright (c) 2017 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
	(http://trustee.ietf.org/license-info) in effect on the date of	(http://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

	skipping to change at page 14, line 22 ¶	skipping to change at page 14, line 22 ¶
	take into account the E and P flags advertised by the next-hop router	take into account the E and P flags advertised by the next-hop router
	if that router advertised the SID for the prefix. This MUST be done	if that router advertised the SID for the prefix. This MUST be done
	regardless of whether the next-hop router contributes to the best	regardless of whether the next-hop router contributes to the best
	path to the prefix.	path to the prefix.

	The NP-Flag (No-PHP) MUST be set and the E-flag MUST be clear for	The NP-Flag (No-PHP) MUST be set and the E-flag MUST be clear for
	Prefix-SIDs allocated to inter-area prefixes that are originated by	Prefix-SIDs allocated to inter-area prefixes that are originated by
	the ABR based on intra-area or inter-area reachability between areas,	the ABR based on intra-area or inter-area reachability between areas,
	unless the advertised prefix is directly attached to the ABR.	unless the advertised prefix is directly attached to the ABR.


	The NP-Flag (No-PHP) MUST be be set and the E-flag MUST be clear for	The NP-Flag (No-PHP) MUST be set and the E-flag MUST be clear for
	Prefix-SIDs allocated to redistributed prefixes, unless the	Prefix-SIDs allocated to redistributed prefixes, unless the
	redistributed prefix is directly attached to the ASBR.	redistributed prefix is directly attached to the ASBR.

	If the NP-Flag is not set, then any upstream neighbor of the Prefix-	If the NP-Flag is not set, then any upstream neighbor of the Prefix-
	SID originator MUST pop the Prefix-SID. This is equivalent to the	SID originator MUST pop the Prefix-SID. This is equivalent to the
	penultimate hop popping mechanism used in the MPLS dataplane. In	penultimate hop popping mechanism used in the MPLS dataplane. In
	such case, MPLS EXP bits of the Prefix-SID are not preserved for the	such case, MPLS EXP bits of the Prefix-SID are not preserved for the
	final destination (the Prefix-SID being removed). If the NP-flag is	final destination (the Prefix-SID being removed). If the NP-flag is
	not set then the received E-flag is ignored.	not set then the received E-flag is ignored.


	skipping to change at page 16, line 12 ¶	skipping to change at page 16, line 12 ¶
	192.0.2.20/30, Prefix-SID: Index 56	192.0.2.20/30, Prefix-SID: Index 56
	192.0.2.24/30, Prefix-SID: Index 57	192.0.2.24/30, Prefix-SID: Index 57

	then the Prefix field in the Extended Prefix Range TLV would be set	then the Prefix field in the Extended Prefix Range TLV would be set
	to 192.0.2.0, Prefix Length would be set to 30, Range Size would be	to 192.0.2.0, Prefix Length would be set to 30, Range Size would be
	7, and the Index value in the Prefix-SID Sub-TLV would be set to 51.	7, and the Index value in the Prefix-SID Sub-TLV would be set to 51.

	6. SID/Label Binding Sub-TLV	6. SID/Label Binding Sub-TLV

	The SID/Label Binding Sub-TLV is used to advertise a SID/Label	The SID/Label Binding Sub-TLV is used to advertise a SID/Label

	mapping for a path to the a prefix.	mapping for a path to the prefix.

	The SID/Label Binding Sub-TLV MAY be originated by any router in an	The SID/Label Binding Sub-TLV MAY be originated by any router in an
	OSPF domain. The router may advertise a SID/Label binding to a FEC	OSPF domain. The router may advertise a SID/Label binding to a FEC
	along with at least a single 'nexthop style' anchor. The protocol	along with at least a single 'nexthop style' anchor. The protocol
	supports more than one 'nexthop style' anchor to be attached to a	supports more than one 'nexthop style' anchor to be attached to a
	SID/Label binding, which results in a simple path description	SID/Label binding, which results in a simple path description
	language. Analogous to RSVP, the terminology for this is called an	language. Analogous to RSVP, the terminology for this is called an
	'Explicit Route Object' (ERO). Since ERO-style path notation allows	'Explicit Route Object' (ERO). Since ERO-style path notation allows
	anchoring SID/label bindings to both link and node IP addresses, any	anchoring SID/label bindings to both link and node IP addresses, any
	Label Switched Path (LSP) can be described. Additionally, SID/Label	Label Switched Path (LSP) can be described. Additionally, SID/Label

	skipping to change at page 18, line 30 ¶	skipping to change at page 18, line 30 ¶

	Length: Always 4	Length: Always 4

	Metric: A 4-octet metric representing the aggregate IGP or TE path	Metric: A 4-octet metric representing the aggregate IGP or TE path
	cost.	cost.

	6.2. ERO Sub-TLVs	6.2. ERO Sub-TLVs

	All ERO information represents an ordered set which describes the	All ERO information represents an ordered set which describes the
	segments of a path. The first ERO Sub-TLV describes the first	segments of a path. The first ERO Sub-TLV describes the first

	segment of a path. Similiarly, the last ERO Sub-TLV describes the	segment of a path. Similarly, the last ERO Sub-TLV describes the
	segment closest to the egress point. If a router extends or stitches	segment closest to the egress point. If a router extends or stitches
	a path, it MUST prepend the new segment's path information to the ERO	a path, it MUST prepend the new segment's path information to the ERO
	list. This applies equally to advertised backup EROs.	list. This applies equally to advertised backup EROs.

	All ERO sub-TLVs are sub-TLVs of the SID/Label Binding TLV.	All ERO sub-TLVs are sub-TLVs of the SID/Label Binding TLV.

	6.2.1. IPv4 ERO Sub-TLV	6.2.1. IPv4 ERO Sub-TLV

	The IPv4 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV.	The IPv4 ERO Sub-TLV is a Sub-TLV of the SID/Label Binding Sub-TLV.


End of changes. 7 change blocks.
	7 lines changed or deleted	7 lines changed or added
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