IS-IS for IP Internets                                    P. Sarkar, Ed.
Internet-Draft                                                H. Gredler
Intended status: Standards Track                                S. Hegde
Expires: June 10, 2016                            Juniper Networks, Inc.
                                                            S. Litkowski
                                                             B. Decraene
                                                                   Z. Li
                                                     Huawei Technologies
                                                                E. Aries
                                                            R. Rodriguez
                                                            H. Raghuveer
                                                        December 8, 2015

                Advertising Per-node Admin Tags in IS-IS


   This document describes an extension to the IS-IS routing protocol to
   add an optional operational capability, that allows tagging and
   grouping of the nodes in an IS-IS domain.  This allows simple
   management and easy control over route and path selection, based on
   local configured policies.

   This document describes the protocol extensions to disseminate per-
   node administrative tags in IS-IS protocols.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   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

   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 June 10, 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
   ( 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.  Per-Node Administrative Tags  . . . . . . . . . . . . . . . .   3
   3.  Per-Node Administrative Tag Sub-TLV . . . . . . . . . . . . .   3
     3.1.  TLV format  . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Elements of Procedure . . . . . . . . . . . . . . . . . . . .   5
     4.1.  Interpretation of Per-Node Administrative Tags  . . . . .   5
     4.2.  Use of Per-Node Administrative Tags . . . . . . . . . . .   5
     4.3.  Processing Per-Node Administrative Tag changes  . . . . .   6
   5.  Applications  . . . . . . . . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   7.  Operational Considerations  . . . . . . . . . . . . . . . . .  11
   8.  Manageability Considerations  . . . . . . . . . . . . . . . .  12
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  12
   11. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     11.1.  Normative References . . . . . . . . . . . . . . . . . .  12
     11.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   It is useful to assign a per-node administrative tag to a router in
   the IS-IS domain and use it as an attribute associated with the node.
   The per-node administrative tag can be used in variety of
   applications, for example:

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   (a)  Traffic-engineering applications to provide different path-
        selection criteria.

   (b)  Prefer or prune certain paths in Loop Free Alternate (LFA)
        backup selection via local policies as defined in

   This document provides mechanisms to advertise per-node
   administrative tags in IS-IS for route and path selection.  Route and
   path selection functionality applies to both to Traffic
   Engineering(TE) and non-TE applications.  Hence the new TLV for
   carrying per-node administrative tags is included in Router
   Capability TLV [RFC4971].

2.  Per-Node Administrative Tags

   An administrative Tag is a 32-bit integer value that can be used to
   identify a group of nodes in the IS-IS domain.  An IS-IS router
   SHOULD advertise the set of groups it is part of in the specific IS-
   IS level.  As an example, all PE-nodes may be configured with certain
   tag value, whereas all P-nodes are configured with a different tag

3.  Per-Node Administrative Tag Sub-TLV

   The new sub-TLV defined will be carried inside the IS-IS Router
   Capability TLV-242 [RFC4971]) in the Link State PDUs originated by
   the router.  The new sub-TLV specifies one or more administrative tag
   values.  TLV 242 can be either specified to be flooded within the
   specific level in which the same has been originated, or they can be
   specfied to be relayed from originating level to the other levels as
   well.  Per-node administrative tags that are included in a 'level-
   specific' TLV 242 have a 'level-wide' flooding scope associated.  On
   the other hand, per-node administrative tags included in a 'domain-
   wide' TLV 242 have 'domain-wide' flooding scope associated.  For
   details on how TLV 242 are flooded and relayed in the entire network
   please, refer to [RFC4971].  Choosing the flooding scope to be
   associated with group tags, is defined by the needs of the operator's
   usage and is a matter of local policy or configuration.  Operator MAY
   choose to advertise a different set of per-node administrative tags
   across levels and another set of per-node administrative tags within
   the specific level.  Alternatively, the operator may use the same
   per-node administrative tags both within the 'domain-wide' flooding
   scope as well as within one or more 'level-wide' flooding scope.

   Implementations SHOULD allow configuring one or more per-node
   administrative tags to be advertised from a given device along with
   the flooding scope associated with the same.  It SHOULD allow

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   provisioning a set of per-node administrative tags having a 'domain-
   wide' flooding scope, as well as, a set of per-node administrative
   tags with 'level-wide' flooding scope only.  A given per-node
   administrative tag MAY be advertised within one or more 'level-wide'
   flooding scopes and/or within the 'domain-wide' scope.

   The format of per-node Administrative Tag sub-TLV (see Section 3.1)
   does not include a topology identifier.  Therefore it is not possible
   to indicate a topology specific context when advertising per-node
   admin tags.  Hence, in deployments using multi-topology routing
   [RFC5120], advertising a separate set of per-node administrative tags
   for each topology SHOULD NOT be supported.

3.1.  TLV format

   The new Per-node Administrative Tag sub-TLV, like other ISIS
   Capability sub-TLVs, is formatted as Type/Length/Value (TLV)triplets.
   Figure 1 below shows the format of the new sub-TLV.

     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     |
    +- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                   Administrative Tag #1                       |
    |                   Administrative Tag #2                       |
    //                                                             //
    |                   Administrative Tag #N                       |

    Type :  TBA

    Length: A 8-bit field that indicates the length of the value
            portion in octets and will be a multiple of 4 octets
            dependent on the number of tags advertised.

    Value:  A sequence of multiple 4 octets defining the
            administrative tags.

            Figure 1: IS-IS Per-node Administrative Tag sub-TLV

   The 'Per-node Admin Tag' sub-TLV may be generated more than once by
   an originating router.  This MAY happen if a node carries more than
   63 per-node administrative groups and a single sub-TLV does not

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   provide sufficient space.  As such occurrence of the 'Per-node Admin
   Tag' sub-TLV does not cancel previous announcements, but rather is

4.  Elements of Procedure

4.1.  Interpretation of Per-Node Administrative Tags

   Meaning of the Per-node administrative tags is generally opaque to
   IS-IS.  Router advertising the per-node administrative tag (or tags)
   may be configured to do so without knowing (or even explicitly
   supporting) functionality implied by the tag.

   Interpretation of tag values is specific to the administrative domain
   of a particular network operator.  The meaning of a per-node
   administrative tag is defined by the network local policy and is
   controlled via the configuration.  If a receiving node does not
   understand the tag value, it ignores the specific tag and floods the
   Router Capability TLV without any change as defined in [RFC4971].

   The semantics of the tag order has no meaning.  There is no 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

   Each tag SHOULD be treated as an independent identifier that MAY be
   used in policy to perform a policy action.  Each tag carried by the
   The Per-Node Administrative Tag TLVs should be used to indicate a
   characteristic of a node that is independent of the characteristics
   indicated by other adminsitrative tags within the same or another
   instance of a Per-node Administrative Tag sub-TLV.  The list of Per-
   node administrative tags carried in a Per-Node Administrative Tag
   sub-TLV MUST be considered as an unordered list.  Whilst policies may
   be implemented based on the presence of multiple tags (e.g., if tag A
   AND tag B are present), they MUST NOT be reliant upon the order of
   the tags (i.e., all policies should be considered commutative
   operations, such that tag A preceding or following tag B does not
   change their outcome).

4.2.  Use of Per-Node Administrative Tags

   The per-node administrative tags are not meant to be extended by
   future IS-IS standards.  New IS-IS extensions are not expected to
   require use of per-node administrative tags or define well-known tag
   values.  Per-node administrative tags are for generic use and do not
   require IANA registry.  Future IS-IS extensions requiring well known
   values MAY define their own data signalling tailored to the needs of
   the feature or MAY use the capability TLV as defined in [RFC4971].

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   Being part of the Router Capability TLV, the per-node administrative
   tag sub-TLV MUST be reasonably small and stable.  In particular, but
   not limited to, implementations supporting the per-node
   administrative tags MUST NOT associate advertised tags to changes in
   the network topology (both within and outside the IS-IS domain) or
   reachability of routes.

4.3.  Processing Per-Node Administrative Tag changes

   Multiple Per-Node Administrative Tag sub-TLVs MAY appear in a Router
   Capability TLV(TLV-242) or Per-Node Administrative Tag sub-TLVs MAY
   be contained in different instances of Router Capability TLVs.  The
   Per-node administrative tags associated with a node that originates
   tags for the purpose of any computation or processing at a receiving
   node SHOULD be a superset of node administrative tags from all the
   TLVs in all the instances of Router Capability TLVs received in the
   Link-State PDU(s) advertised by the corresponding IS-IS router.  When
   an Router Capability TLV is received that changes the set of per-node
   administrative tags applicable to any originating node, a receiving
   node MUST repeat any computation or processing that makes use of per-
   node administrative tags.

   When there is a change or removal of an administrative affiliation of
   a node, the node MUST re-originate the Router Capability TLV(s) with
   the latest set of per-node administrative tags.  On a receiving
   router, on detecting a change in contents (or removal) of existing
   Per-Node Administrative Tag sub-TLV(s) or addition of new Per-Node
   Administrative Tag sub-TLV(s) in any instance of Router Capability
   TLV(s), implementations MUST take appropriate measures to update
   their state according to the changed set of per-node administrative
   tags.  The exact actions needed depend on features working with per-
   node administrative tags and is outside of scope of this

5.  Applications

   This section lists several non-normative examples of how
   implementations might use Per-node administrative tags.  These
   examples are given only to demonstrate generic usefulness of the
   router tagging mechanism.  An implementation supporting this
   specification is not required to implement any of the use cases.  It
   is also worth noting that in some described use cases routers
   configured to advertise tags help other routers in their calculations
   but do not themselves implement the same functionality.

   1.  Auto-discovery of Services

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       Router tagging may be used to automatically discover group of
       routers sharing a particular service.

       For example, service provider might desire to establish full mesh
       of MPLS TE tunnels between all PE routers in the area of MPLS VPN
       network.  Marking all PE routers with a tag and configuring
       devices with a policy to create MPLS TE tunnels to all other
       devices advertising this tag will automate maintenance of the
       full mesh.  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.

   2.  Policy-based Fast-Re-Route(FRR)

       Increased deployment of Loop Free Alternates (LFA) as defined in
       [RFC5286] poses operation and management challenges.
       [I-D.ietf-rtgwg-lfa-manageability] proposes policies which, when
       implemented, will ease LFA operation concerns.

       One of the proposed refinements is to be able to group the nodes
       in an IGP domain with administrative tags and engineer the LFA
       based on configured policies.

       (a)  Administrative limitation of LFA scope

           Service provider access infrastructure is frequently designed
           in a layered approach with each layer of devices serving
           different purposes and thus having different hardware
           capabilities and configured software features.  When LFA
           repair paths are being computed, it may be desirable to
           exclude devices from being considered as LFA candidates based
           on their layer.

           For example, if the access infrastructure is divided into the
           Access, Distribution and Core layers it may be desirable for
           a Distribution device to compute LFA only via Distribution or
           Core devices but not via Access devices.  This may be due to
           features enabled on Access routers, due to capacity
           limitations or due to the security requirements.  Managing
           such a policy via configuration of the router computing LFA
           is cumbersome and error prone.

           With the Per-node administrative tags it is possible to
           assign a tag to each layer and implement LFA policy of
           computing LFA repair paths only via neighbors which advertise
           the Core or Distribution tag.  This requires minimal per-node
           configuration and network automatically adapts when new links
           or routers are added.

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       (b)  Optimizing LFA calculations

           Calculation of LFA paths may require significant resources of
           the router.  One execution of Dijkstra algorithm is required
           for each neighbor eligible to become next hop of repair
           paths.  Thus a router with a few hundreds of neighbors may
           need to execute the algorithm hundreds of times before the
           best (or even valid) repair path is found.  Manually
           excluding from the calculation neighbors which are known to
           provide no valid LFA (such as single-connected routers) may
           significantly reduce number of Dijkstra algorithm runs.

           LFA calculation policy may be configured so that routers
           advertising certain tag value are excluded from LFA
           calculation even if they are otherwise suitable.

   3.  Controlling Remote LFA tunnel termination

       [RFC7490] defined method of tunneling traffic after connected
       link failure to extend the basic LFA coverage and algorithm to
       find tunnel tail-end routers fitting LFA requirement.  In most
       cases proposed algorithm finds more than one candidate tail-end
       router.  In real 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 known limitations of the per-node (the
       router does accept targeted LDP sessions required to implement
       Remote LFA tunneling) or due to administrative requirements (for
       example, it may be desirable to choose tail-end router among co-
       located devices).

       The Per-node administrative tag delivers simple and scalable
       solution.  Remote LFA can be configured with a policy to accept
       during the tail-end router calculation as candidates only routers
       advertising certain tag.  Tagging routers allows to both exclude
       nodes not capable of serving as Remote LFA tunnel tail-ends and
       to define a region from which tail-end router must be selected.

   4.  Mobile back-haul network service deployment

       The topology of mobile back-haul networks usually adopts ring
       topology to save fiber resource and it is divided into the
       aggregate network and the access network.  Cell Site
       Gateways(CSGs) connects the eNodeBs and RNC(Radio Network
       Controller) Site Gateways(RSGs)connects the RNCs.  The mobile
       traffic is transported from CSGs to RSGs.  The network takes a
       typical aggregate traffic model that more than one access rings
       will attach to one pair of aggregate site gateways(ASGs) and more
       than one aggregate rings will attach to one pair of RSGs.

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                   /                \
                  /                  \
                 /                    \
    +------+   +----+    Access     +----+
    |eNodeB|---|CSG1|    Ring 1     |ASG1|-------------
    +------+   +----+               +----+             \
                 \                    /                 \
                  \                  /                   +----+    +---+
                   \             +----+                  |RSG1|----|RNC|
                    -------------|    |    Aggregate     +----+    +---+
                                 |ASG2|      Ring          |
                    -------------|    |                  +----+    +---+
                   /             +----+                  |RSG2|----|RNC|
                  /                  \                   +----+    +---+
                 /                    \                 /
    +------+   +----+     Access     +----+            /
    |eNodeB|---|CSG2|     Ring 2     |ASG3|------------
    +------+   +----+                +----+
                \                     /
                 \                   /
                  \                 /

                     Figure 2: Mobile Backhaul Network

       A typical mobile back-haul network with access rings and
       aggregate links is shown in figure above.  The mobile back-haul
       networks deploy traffic engineering due to the strict Service
       Level Agreements(SLA).  The TE paths may have additional
       constraints to avoid passing via different access rings or to get
       completely disjoint backup TE paths.  The mobile back-haul
       networks towards the access side change frequently due to the
       growing mobile traffic and addition of new LTE Evolved NodeBs
       (eNodeB).  It's complex to satisfy the requirements using cost,
       link color or explicit path configurations.  The per-node
       administrative tag defined in this document can be effectively
       used to solve the problem for mobile back-haul networks.  The
       nodes in different rings can be assigned with specific tags.  TE
       path computation can be enhanced to consider additional
       constraints based on per-node administrative tags.

   5.  Policy-based Explicit Routing

       A partially meshed network provides multiple paths between any
       two nodes in the network.  In a data centre environment, the
       topology is usually highly symmetric with many/all paths having

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       equal cost.  In a long distance network, this is usually less the
       case, for a variety of reasons (e.g. historic, fibre availability
       constraints, different distances between transit nodes, different
       roles ...).  Hence between a given source and destination, a path
       is typically preferred over the others, while between the same
       source and another destination, a different path may be

        +----------------------+   +----------------+
        |                       \ /                 |
        |   +-----------------+  x   +---------+    |
        |   |                  \/  \/          |    |
        |   |                +-T-10-T          |    |
        |   |               /  |   /|          |    |
        |   |              /  100 / |          |    |
        |   |             /    | | 100         |    |
        |   |            /   +-+-+  |          |    |
        |   |           /   /  |    |          |    |
        |   |          /   /   R-18-R          |    |
        |   |        10   10  /\   /\          |    |
        |   |        /   /   /  \ /  \         |    |
        |   |       /   /   /    x    \        |    |
        |   |      /   /   10  10 \    \       |    |
        |   |     /   /   /    /   10   10     |    |
        |   |    /   /   /    /     \    \     |    |
        |   |   A-25-A  A-25-A       A-25-A    |    |
        |   |   |    |   \    \     /    /     |    |
        |   |   |    |   201  201  201 201     |    |
        |   |   |    |     \    \ /    /       |    |
        |   |  201  201     \    x    /        |    |
        |   |   |    |       \  / \  /         |    |
        |   |   |    |        \/   \/          |    |
        |   |   I-24-I        I-24-I          100  100
        |   |  /    /         |    |           |    |
        |   +-+    /          |    +-----------+    |
        +---------+           +---------------------+

                    Figure 3: Explicit Routing topology

       In the above topology, operator may want to enforce the following
       high level explicit routing policies:

       1.  - Traffic from A nodes to A nodes should preferably go
           through R or T nodes (rather than through I nodes).

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       2.  - Traffic from A nodes to I nodes must not go through R and T

       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.  The first
       policy is about preferring one path over another.  Given the
       chosen metrics, it is achieved with regular SPF routing.  The
       second policy is about prohibiting (pruning) some paths.  It
       requires an explicit routing policy.  With the use of node tags,
       this may be achieved with a generic CSPF policy configured on A
       nodes: for destination nodes having the tag "A" runs a CSPF with
       the exclusion of nodes having the tag "I".

6.  Security Considerations

   Node administrative tags may be used by operators to indicate
   geographical location or other sensitive information.  The
   information carried in node administrative tags could be leaked to an
   IGP snooper.  This document does not introduce any new security
   issues.  Security concerns for IS-IS are already addressed in
   [ISO10589], [RFC5304], and [RFC5310] and are applicable to the
   mechanisms described in this document.  Extended authentication
   mechanisms described in [RFC5304] or [RFC5310] SHOULD be used in
   deployments where attackers have access to the physical networks and
   nodes included in the IS-IS domain are vulnerable.

   Advertisement of tag values for one administrative domain into
   another invloves the risk mis-interpretation of the tag values (if
   the two domains have assigned different meanings to the same values),
   which may have undesirable and unanticipated side effects.

7.  Operational Considerations

   Operators can assign meaning to the per-node administrative tags
   which is local to the operator's administrative domain.  The
   operational use of per-node administrative tags is analogical to the
   IS-IS prefix tags [RFC5130] and BGP communities [RFC1997].
   Operational discipline and procedures followed in configuring and
   using BGP communities and ISIS Prefix tags is also applicable to the
   usage of per-node administrative tags.

   Defining language for local policies is outside the scope of this
   document.  As in case of other policy applications, the pruning
   policies can cause the path to be completely removed from forwarding
   plane,and hence have the potential for more severe operational impact
   (e.g., node unreachability due to path removal) by comparison to
   preference policies that only affect path selection.

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8.  Manageability Considerations

   Per-node administrative tags are configured and managed using routing
   policy enhancements.  YANG data definition language is the latest
   model to describe and define configuration for network devices.  IS-
   IS YANG data model is described in [I-D.ietf-isis-yang-isis-cfg] and
   routing policy configuration model is described in
   [I-D.ietf-rtgwg-policy-model].  These two documents will be enhanced
   to include the node administrative tag related configurations.

9.  IANA Considerations

   IANA maintains the registry for the Router Capability sub-TLVs.  IS-
   IS Administrative Tags will require new type code for the following
   new sub-TLV defined in this document.

   i) Per-Node-Admin-Tag Sub-TLV, Type: TBD

10.  Acknowledgments

   Many thanks to Les Ginsberg, Dhruv Dhody, Uma Chunduri and Chris
   Bowers for providing useful inputs.

11.  References

11.1.  Normative References

              "Intermediate system to Intermediate system intra-domain
              routeing information exchange protocol for use in
              conjunction with the protocol for providing the
              connectionless-mode Network Service (ISO 8473), ISO/IEC
              10589:2002, Second Edition.", Nov 2002.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,

   [RFC4971]  Vasseur, JP., Ed., Shen, N., Ed., and R. Aggarwal, Ed.,
              "Intermediate System to Intermediate System (IS-IS)
              Extensions for Advertising Router Information", RFC 4971,
              DOI 10.17487/RFC4971, July 2007,

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   [RFC5304]  Li, T. and R. Atkinson, "IS-IS Cryptographic
              Authentication", RFC 5304, DOI 10.17487/RFC5304, October
              2008, <>.

   [RFC5310]  Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R.,
              and M. Fanto, "IS-IS Generic Cryptographic
              Authentication", RFC 5310, DOI 10.17487/RFC5310, February
              2009, <>.

   [RFC7490]  Bryant, S., Filsfils, C., Previdi, S., Shand, M., and N.
              So, "Remote Loop-Free Alternate (LFA) Fast Reroute (FRR)",
              RFC 7490, DOI 10.17487/RFC7490, April 2015,

11.2.  Informative References

              Litkowski, S., Yeung, D., Lindem, A., Zhang, J., and L.
              Lhotka, "YANG Data Model for IS-IS protocol", draft-ietf-
              isis-yang-isis-cfg-07 (work in progress), November 2015.

              Litkowski, S., Decraene, B., Filsfils, C., Raza, K.,
              Horneffer, M., and P. Sarkar, "Operational management of
              Loop Free Alternates", draft-ietf-rtgwg-lfa-
              manageability-11 (work in progress), June 2015.

              Shaikh, A.,, r., D'Souza, K., and C. Chase,
              "Routing Policy Configuration Model for Service Provider
              Networks", draft-ietf-rtgwg-policy-model-00 (work in
              progress), September 2015.

   [RFC1997]  Chandra, R., Traina, P., and T. Li, "BGP Communities
              Attribute", RFC 1997, DOI 10.17487/RFC1997, August 1996,

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,

   [RFC5130]  Previdi, S., Shand, M., Ed., and C. Martin, "A Policy
              Control Mechanism in IS-IS Using Administrative Tags",
              RFC 5130, DOI 10.17487/RFC5130, February 2008,

Sarkar, et al.            Expires June 10, 2016                [Page 13]

Internet-Draft  Advertising Per-node Admin Tags in IS-IS   December 2015

   [RFC5286]  Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
              IP Fast Reroute: Loop-Free Alternates", RFC 5286,
              DOI 10.17487/RFC5286, September 2008,

Authors' Addresses

   Pushpasis Sarkar (editor)
   Juniper Networks, Inc.
   Electra, Exora Business Park
   Bangalore, KA  560103


   Hannes Gredler
   Juniper Networks, Inc.
   1194 N. Mathilda Ave.
   Sunnyvale, CA  94089


   Shraddha Hegde
   Juniper Networks, Inc.
   Electra, Exora Business Park
   Bangalore, KA  560103


   Stephane Litkowski


   Bruno Decraene


Sarkar, et al.            Expires June 10, 2016                [Page 14]

Internet-Draft  Advertising Per-node Admin Tags in IS-IS   December 2015

   Li Zhenbin
   Huawei Technologies
   Huawei Bld. No.156 Beiqing Rd
   Beijing, KA  100095


   Ebben Aries
   1 Hacker Way
   Menlo Park, CA  94025


   Rafael Rodriguez
   1 Hacker Way
   Menlo Park, CA  94025


   Harish Raghuveer


Sarkar, et al.            Expires June 10, 2016                [Page 15]