draft-ietf-ospf-node-admin-tag-04.txt   draft-ietf-ospf-node-admin-tag-05.txt 
Open Shortest Path First IGP S. Hegde Open Shortest Path First IGP S. Hegde
Internet-Draft Juniper Networks, Inc. Internet-Draft Juniper Networks, Inc.
Intended status: Standards Track H. Raghuveer Intended status: Standards Track H. Gredler
Expires: March 12, 2016 Expires: March 27, 2016 R. Shakir
H. Gredler
Juniper Networks, Inc.
R. Shakir
Individual Individual
A. Smirnov A. Smirnov
Cisco Systems, Inc. Cisco Systems, Inc.
Z. Li Z. Li
Huawei Technologies Huawei Technologies
B. Decraene B. Decraene
Orange Orange
September 9, 2015 September 24, 2015
Advertising per-node administrative tags in OSPF Advertising per-node administrative tags in OSPF
draft-ietf-ospf-node-admin-tag-04 draft-ietf-ospf-node-admin-tag-05
Abstract Abstract
This document describes an extension to OSPF protocol to add an This document describes an extension to OSPF protocol to add an
optional operational capability, that allows tagging and grouping of optional operational capability, that allows tagging and grouping of
the nodes in an OSPF domain. This allows simplification, ease of the nodes in an OSPF domain. This allows simplification, ease of
management and control over route and path selection based on management and control over route and path selection based on
configured policies. This document describes an extension to OSPF configured policies. This document describes an extension to OSPF
protocol to advertise per-node administrative tags. This optional protocol to advertise per-node administrative tags. The node-tags
operational capability allows to express and act upon locally-defined can be used to express and apply locally-defined network policies
network policy which considers node properties conveyed by tags. which is a very useful operational capability. Node tags may be used
Node tags may be used either by OSPF itself or by other applications either by OSPF itself or by other applications consuming information
consuming information propagated via OSPF. propagated via OSPF.
This document describes the protocol extensions to disseminate per- This document describes the protocol extensions to disseminate per-
node administrative-tags to the OSPFv2 and OSPFv3 protocol. It node administrative-tags to the OSPFv2 and OSPFv3 protocol. It
provides example use cases of administrative node tags. provides example use cases of administrative node tags.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
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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 March 12, 2016. This Internet-Draft will expire on March 27, 2016.
Copyright Notice Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the Copyright (c) 2015 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
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Administrative Tag TLV . . . . . . . . . . . . . . . . . . . 3 2. Administrative Tag TLV . . . . . . . . . . . . . . . . . . . 3
3. OSPF per-node administrative tag TLV . . . . . . . . . . . . 3 3. OSPF per-node administrative tag TLV . . . . . . . . . . . . 3
3.1. TLV format . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. TLV format . . . . . . . . . . . . . . . . . . . . . . . 3
3.2. Elements of procedure . . . . . . . . . . . . . . . . . . 4 3.2. Elements of procedure . . . . . . . . . . . . . . . . . . 4
4. Applications . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Applications . . . . . . . . . . . . . . . . . . . . . . . . 5
4.1. Service auto-discovery . . . . . . . . . . . . . . . . . 6 4.1. Service auto-discovery . . . . . . . . . . . . . . . . . 6
4.2. Fast-Rerouting policy . . . . . . . . . . . . . . . . . . 6 4.2. Fast-Re-routing policy . . . . . . . . . . . . . . . . . 6
4.3. Controlling Remote LFA tunnel termination . . . . . . . . 7 4.3. Controlling Remote LFA tunnel termination . . . . . . . . 7
4.4. Mobile backhaul network service deployment . . . . . . . 7 4.4. Mobile back-haul network service deployment . . . . . . . 7
4.5. Explicit routing policy . . . . . . . . . . . . . . . . . 9 4.5. Explicit routing policy . . . . . . . . . . . . . . . . . 9
5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 10 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10
8.1. Normative References . . . . . . . . . . . . . . . . . . 10 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
8.2. Informative References . . . . . . . . . . . . . . . . . 11 9.1. Normative References . . . . . . . . . . . . . . . . . . 10
9.2. Informative References . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction 1. Introduction
It is useful to assign a per-node administrative tag to a router in It is useful to assign a per-node administrative tag to a router in
the OSPF domain and use it as an attribute associated with the node. the OSPF domain and use it as an attribute associated with the node.
The per-node administrative tag can be used in variety of The per-node administrative tag can be used in variety of
applications, for ex: - Traffic-engineering applications to provide applications, for ex: - Traffic-engineering applications to provide
different path-selection criteria, - Prefer or prune certain paths in different path-selection criteria, - Prefer or prune certain paths in
Loop Free Alternate (LFA) backup selection via local policies. Loop Free Alternate (LFA) backup selection via local policies.
This document provides mechanisms to advertise per-node This document provides mechanisms to advertise per-node
administrative tags in the OSPF. Path selection is a functional set administrative tags in OSPF. Path selection is a functional set
which applies both to TE and non-TE applications and hence new TLV which applies both to TE and non-TE applications and hence new TLV
for carrying per-node administrative tags is included in Router for carrying per-node administrative tags is included in Router
Information LSA [RFC4970] . Information LSA [RFC4970] .
2. Administrative Tag TLV 2. Administrative Tag TLV
An administrative Tag is a 32-bit integer value that can be used to An administrative Tag is a 32-bit integer value that can be used to
identify a group of nodes in the OSPF domain. identify a group of nodes in the OSPF domain.
The new TLV defined will be carried within an RI LSA for OSPFV2 and The new TLV defined will be carried within an RI LSA for OSPFV2 and
OSPFV3. Router information LSA [RFC4970] can have link, area or AS OSPFV3. Router information LSA [RFC4970] can have link, area or AS
level flooding scope. Choosing the flooding scope to flood the group level flooding scope. Choosing the flooding scope to flood the group
tags are defined by the policies and is a local matter. tags are defined by the policies and is a local matter.
The TLV specifies one or more administrative tag values. An OSPF The TLV specifies one or more administrative tag values. An OSPF
node advertises the set of groups it is part of in the OSPF domain. node advertises the set of groups it is part of in the OSPF domain.
(for example, all PE-nodes are configured with certain tag value, all (for example, all PE-nodes are configured with certain tag value, all
P-nodes are configured with a different tag value in a domain). P-nodes are configured with a different tag value in the domain).
Multiple TLVs MAY be added in same RI-LSA or in different instance of Multiple TLVs MAY be added in same RI-LSA or in a different instance
the RI LSA as defined in [I-D.acee-ospf-rfc4970bis]. of the RI LSA as defined in [I-D.acee-ospf-rfc4970bis].
3. OSPF per-node administrative tag TLV 3. OSPF per-node administrative tag TLV
3.1. TLV format 3.1. TLV format
[RFC4970], defines Router Information (RI) LSA which may be used to [RFC4970], defines Router Information (RI) LSA which may be used to
advertise properties of the originating router. Payload of the RI advertise properties of the originating router. Payload of the RI
LSA consists of one or more nested Type/Length/Value (TLV) triplets. LSA consists of one or more nested Type/Length/Value (TLV) triplets.
Node administrative tags are advertised in the Node Administrative Node administrative tags are advertised in the Node Administrative
Tag TLV. The format of Node Administrative Tag TLV is: Tag TLV. The format of Node Administrative Tag TLV is:
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RI LSA without any change as defined in [RFC4970]. RI LSA without any change as defined in [RFC4970].
The semantics of the tag order has no meaning. That is, there is no The semantics of the tag order has no meaning. That is, there is no
implied meaning to the ordering of the tags that indicates a certain implied meaning to the ordering of the tags that indicates a certain
operation or set of operations that need to be performed based on the operation or set of operations that need to be performed based on the
ordering. ordering.
Each tag SHOULD be treated as an independent identifier that MAY be Each tag SHOULD be treated as an independent identifier that MAY be
used in policy to perform a policy action. Tags carried by the used in policy to perform a policy action. Tags carried by the
administrative tag TLV SHOULD be used to indicate independent administrative tag TLV SHOULD be used to indicate independent
characteristics of a node. The TLV SHOULD be considered an unordered characteristics of a node. The administrative tag list within the
list. Whilst policies may be implemented based on the presence of TLV SHOULD be considered an unordered list. Whilst policies may be
multiple tags (e.g., if tag A AND tag B are present), they MUST NOT implemented based on the presence of multiple tags (e.g., if tag A
be reliant upon the order of the tags (i.e., all policies should be AND tag B are present), they MUST NOT be reliant upon the order of
considered commutative operations, such that tag A preceding or the tags (i.e., all policies should be considered commutative
following tag B does not change their outcome). operations, such that tag A preceding or following tag B does not
change their outcome).
To avoid incomplete or inconsistent interpretations of the per-node To avoid incomplete or inconsistent interpretations of the per-node
administrative tags the same tag value MUST NOT be advertised by a administrative tags the same tag value MUST NOT be advertised by a
router in RI LSAs of different scopes. The same tag MAY be router in RI LSAs of different scopes. The same tag MAY be
advertised in multiple RI LSAs of the same scope, for example, OSPF advertised in multiple RI LSAs of the same scope, for example, OSPF
Area Border Router (ABR) may advertise the same tag in area-scope RI Area Border Router (ABR) may advertise the same tag in area-scope RI
LSAs in multiple areas connected to the ABR. LSAs in multiple areas connected to the ABR.
The per-node administrative tags are not meant to be extended by the The per-node administrative tags are not meant to be extended by the
future OSPF standards. The new OSPF extensions MUST NOT require use future OSPF standards. The new OSPF extensions MUST NOT require use
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sharing a particular service. sharing a particular service.
For example, service provider might desire to establish full mesh of For example, service provider might desire to establish full mesh of
MPLS TE tunnels between all PE routers in the area of MPLS VPN MPLS TE tunnels between all PE routers in the area of MPLS VPN
network. Marking all PE routers with a tag and configuring devices network. Marking all PE routers with a tag and configuring devices
with a policy to create MPLS TE tunnels to all other devices with a policy to create MPLS TE tunnels to all other devices
advertising this tag will automate maintenance of the full mesh. advertising this tag will automate maintenance of the full mesh.
When new PE router is added to the area, all other PE devices will When new PE router is added to the area, all other PE devices will
open TE tunnels to it without the need of reconfiguring them. open TE tunnels to it without the need of reconfiguring them.
4.2. Fast-Rerouting policy 4.2. Fast-Re-routing policy
Increased deployment of Loop Free Alternates (LFA) as defined in Increased deployment of Loop Free Alternates (LFA) as defined in
[RFC5286] poses operation and management challenges. [RFC5286] poses operation and management challenges.
[I-D.ietf-rtgwg-lfa-manageability] proposes policies which, when [I-D.ietf-rtgwg-lfa-manageability] proposes policies which, when
implemented, will ease LFA operation concerns. implemented, will ease LFA operation concerns.
One of the proposed refinements is to be able to group the nodes in One of the proposed refinements is to be able to group the nodes in
IGP domain with administrative tags and engineer the LFA based on IGP domain with administrative tags and engineer the LFA based on
configured policies. configured policies.
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neighbors which are known to provide no valid LFA (such as neighbors which are known to provide no valid LFA (such as
single-connected routers) may significantly reduce number of single-connected routers) may significantly reduce number of
Dijkstra algorithm runs. Dijkstra algorithm runs.
LFA calculation policy may be configured so that routers LFA calculation policy may be configured so that routers
advertising certain tag value are excluded from LFA calculation advertising certain tag value are excluded from LFA calculation
even if they are otherwise suitable. even if they are otherwise suitable.
4.3. Controlling Remote LFA tunnel termination 4.3. Controlling Remote LFA tunnel termination
[RFC7490] proposed method of tunneling traffic after connected link [RFC7490] defined a method of tunnelling traffic after connected link
failure to extend the basic LFA coverage and algorithm to find tunnel failure to extend the basic LFA coverage and algorithm to find tunnel
tail-end routers fitting LFA requirement. In most cases proposed tail-end routers fitting LFA requirement. In most cases proposed
algorithm finds more than one candidate tail-end router. In real algorithm finds more than one candidate tail-end router. In real
life network it may be desirable to exclude some nodes from the list life network it may be desirable to exclude some nodes from the list
of candidates based on the local policy. This may be either due to of candidates based on the local policy. This may be either due to
known limitations of the node (the router does not accept targeted known limitations of the node (the router does not accept targeted
LDP sessions required to implement Remote LFA tunnelling) or due to LDP sessions required to implement Remote LFA tunnelling) or due to
administrative requirements (for example, it may be desirable to administrative requirements (for example, it may be desirable to
choose tail-end router among co-located devices). choose tail-end router among co-located devices).
The Node administrative tag delivers simple and scalable solution. The Node administrative tag delivers simple and scalable solution.
Remote LFA can be configured with a policy to accept during the tail- Remote LFA can be configured with a policy to accept during the tail-
end router calculation as candidates only routers advertising certain end router calculation as candidates only routers advertising certain
tag. Tagging routers allows to both exclude nodes not capable of tag. Tagging routers allows to both exclude nodes not capable of
serving as Remote LFA tunnel tail-ends and to define a region from serving as Remote LFA tunnel tail-ends and to define a region from
which tail-end router must be selected. which tail-end router must be selected.
4.4. Mobile backhaul network service deployment 4.4. Mobile back-haul network service deployment
The topology of mobile back-haul network usually adopts ring topology The topology of mobile back-haul network usually adopts ring topology
to save fibre resource and it is divided into the aggregate network to save fibre resource and it is divided into the aggregate network
and the access network. Cell Site Gateways(CSGs) connects the and the access network. Cell Site Gateways(CSGs) connects the
eNodeBs and RNC(Radio Network Controller) Site Gateways(RSGs) eNodeBs and RNC(Radio Network Controller) Site Gateways(RSGs)
connects the RNCs. The mobile traffic is transported from CSGs to connects the RNCs. The mobile traffic is transported from CSGs to
RSGs. The network takes a typical aggregate traffic model that more RSGs. The network takes a typical aggregate traffic model that more
than one access rings will attach to one pair of aggregate site than one access rings will attach to one pair of aggregate site
gateways(ASGs) and more than one aggregate rings will attach to one gateways(ASGs) and more than one aggregate rings will attach to one
pair of RSGs. pair of RSGs.
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nodes nodes
With node admin tags, tag A (resp. I, R, T) can be configured on all With node admin tags, tag A (resp. I, R, T) can be configured on all
A (resp. I, R, T) nodes to advertise their role. Then a generic A (resp. I, R, T) nodes to advertise their role. Then a generic
CSPF policy can be configured on all A nodes to enforce the above CSPF policy can be configured on all A nodes to enforce the above
explicit routing objectives. (e.g. CSPF to destinations A exclude explicit routing objectives. (e.g. CSPF to destinations A exclude
node with tags I). node with tags I).
5. Security Considerations 5. Security Considerations
This document does not introduce any further security issues other Node admin tags may be used by operators to indicate geographical
than those discussed in [RFC2328] and [RFC5340]. location or other sensitive information. As indicated in [RFC2328]
and [RFC5340] OSPF authentication mechanisms do not provide
confidentiality and the information carried in node admin tags could
be leaked to an IGP snooper.
6. IANA Considerations 6. IANA Considerations
This specification updates one OSPF registry: OSPF Router Information This specification updates one OSPF registry: OSPF Router Information
(RI) TLVs Registry (RI) TLVs Registry
i) TBD - Node Admin tag TLV i) Node Admin tag TLV - Suggested value 10
7. Acknowledgments 7. Contributors
Thanks to Harish Raguveer for his contributions to initial versions
of the draft.
8. Acknowledgements
Thanks to Bharath R, Pushpasis Sarakar and Dhruv Dhody for useful Thanks to Bharath R, Pushpasis Sarakar and Dhruv Dhody for useful
inputs. Thanks to Chris Bowers for providing useful inputs to remove inputs. Thanks to Chris Bowers for providing useful inputs to remove
ambiguity related to tag-ordering. Thanks to Les Ginsberg and Acee ambiguity related to tag-ordering. Thanks to Les Ginsberg and Acee
Lindem for the inputs. Lindem for the inputs.
8. References 9. References
8.1. Normative References 9.1. Normative References
[I-D.acee-ospf-rfc4970bis] [I-D.acee-ospf-rfc4970bis]
Lindem, A., Shen, N., Vasseur, J., Aggarwal, R., and S. Lindem, A., Shen, N., Vasseur, J., Aggarwal, R., and S.
Shaffer, "Extensions to OSPF for Advertising Optional Shaffer, "Extensions to OSPF for Advertising Optional
Router Capabilities", draft-acee-ospf-rfc4970bis-00 (work Router Capabilities", draft-acee-ospf-rfc4970bis-00 (work
in progress), July 2014. in progress), July 2014.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
skipping to change at page 11, line 19 skipping to change at page 11, line 28
[RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF
for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008,
<http://www.rfc-editor.org/info/rfc5340>. <http://www.rfc-editor.org/info/rfc5340>.
[RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N. [RFC7490] Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)", So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
RFC 7490, DOI 10.17487/RFC7490, April 2015, RFC 7490, DOI 10.17487/RFC7490, April 2015,
<http://www.rfc-editor.org/info/rfc7490>. <http://www.rfc-editor.org/info/rfc7490>.
8.2. Informative References 9.2. Informative References
[I-D.ietf-rtgwg-lfa-manageability] [I-D.ietf-rtgwg-lfa-manageability]
Litkowski, S., Decraene, B., Filsfils, C., Raza, K., Litkowski, S., Decraene, B., Filsfils, C., Raza, K.,
Horneffer, M., and P. Sarkar, "Operational management of Horneffer, M., and P. Sarkar, "Operational management of
Loop Free Alternates", draft-ietf-rtgwg-lfa- Loop Free Alternates", draft-ietf-rtgwg-lfa-
manageability-11 (work in progress), June 2015. manageability-11 (work in progress), June 2015.
[RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for [RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
IP Fast Reroute: Loop-Free Alternates", RFC 5286, IP Fast Reroute: Loop-Free Alternates", RFC 5286,
DOI 10.17487/RFC5286, September 2008, DOI 10.17487/RFC5286, September 2008,
skipping to change at page 11, line 41 skipping to change at page 12, line 4
Authors' Addresses Authors' Addresses
Shraddha Hegde Shraddha Hegde
Juniper Networks, Inc. Juniper Networks, Inc.
Embassy Business Park Embassy Business Park
Bangalore, KA 560093 Bangalore, KA 560093
India India
Email: shraddha@juniper.net Email: shraddha@juniper.net
Harish Raghuveer
Email: harish.r.prabhu@gmail.com
Hannes Gredler Hannes Gredler
Juniper Networks, Inc. Individual
1194 N. Mathilda Ave.
Sunnyvale, CA 94089
US
Email: hannes@juniper.net Email: hannes@gredler.at
Rob Shakir Rob Shakir
Individual Individual
Email: rjs@rob.sh Email: rjs@rob.sh
Anton Smirnov Anton Smirnov
Cisco Systems, Inc. Cisco Systems, Inc.
De Kleetlaan 6a De Kleetlaan 6a
Diegem 1831 Diegem 1831
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