Internet Engineering Task Force (IETF)                          M. Umair
Request for Comments: 8385                                         Cisco
Category: Informational                               S. Kingston Smiler
ISSN: 2070-1721                                            PALC Networks
                                                        D. Eastlake 3rd
                                                                 Huawei
                                                                L. Yong
                                                            Independent
                                                              June 2018


         Transparent Interconnection of Lots of Links (TRILL)
                   Transparent Transport over MPLS

Abstract

  This document specifies methods to interconnect multiple TRILL
  (Transparent Interconnection of Lots of Links) sites with an
  intervening MPLS network using existing TRILL and VPLS (Virtual
  Private LAN Service) standards.  This document addresses two
  problems: 1) providing connection between more than two TRILL sites
  that are separated by an MPLS provider network and 2) providing a
  single logical virtualized TRILL network for different tenants that
  are separated by an MPLS provider network.

Status of This Memo

  This document is not an Internet Standards Track specification; it is
  published for informational purposes.

  This document is a product of the Internet Engineering Task Force
  (IETF).  It represents the consensus of the IETF community.  It has
  received public review and has been approved for publication by the
  Internet Engineering Steering Group (IESG).  Not all documents
  approved by the IESG are a candidate for any level of Internet
  Standard; see Section 2 of RFC 7841.

  Information about the current status of this document, any errata,
  and how to provide feedback on it may be obtained at
  https://www.rfc-editor.org/info/rfc8385.











Umair, et al.                 Informational                     [Page 1]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


Copyright Notice

  Copyright (c) 2018 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 ....................................................3
     1.1. Terminology ................................................3
  2. TRILL-over-MPLS Model ...........................................5
  3. VPLS Model ......................................................5
     3.1. Entities in the VPLS Model .................................6
     3.2. TRILL Adjacency for VPLS Model .............................7
     3.3. MPLS Encapsulation for VPLS Model ..........................7
     3.4. Loop-Free Provider PSN/MPLS ................................7
     3.5. Frame Processing ...........................................7
  4. VPTS Model ......................................................7
     4.1. Entities in the VPTS Model .................................9
          4.1.1. TRILL Intermediate Router (TIR) ....................10
          4.1.2. Virtual TRILL Switch/Service Domain (VTSD) .........10
     4.2. TRILL Adjacency for VPTS Model ............................10
     4.3. MPLS Encapsulation for VPTS Model .........................10
     4.4. Loop-Free Provider PSN/MPLS ...............................11
     4.5. Frame Processing ..........................................11
          4.5.1. Multi-destination Frame Processing .................11
          4.5.2. Unicast Frame Processing ...........................11
  5. VPTS Model versus VPLS Model ...................................11
  6. Packet Processing between Pseudowires ..........................12
  7. Efficiency Considerations ......................................12
  8. Security Considerations ........................................12
  9. IANA Considerations ............................................13
  10. References ....................................................13
      10.1. Normative References ....................................13
      10.2. Informative References ..................................14
  Acknowledgements ..................................................15
  Authors' Addresses ................................................16





Umair, et al.                 Informational                     [Page 2]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


1.  Introduction

  The IETF Transparent Interconnection of Lots of Links (TRILL)
  protocol [RFC6325] [RFC7177] [RFC7780] provides transparent
  forwarding in multi-hop networks with arbitrary topology and link
  technologies using a header with a hop count and link-state routing.
  TRILL provides optimal pair-wise forwarding without configuration,
  safe forwarding even during periods of temporary loops, and support
  for multipathing of both unicast and multicast traffic.  Intermediate
  Systems (ISs) implementing TRILL are called Routing Bridges
  (RBridges) or TRILL switches.

  This document, in conjunction with [RFC7173] on TRILL transport using
  pseudowires, addresses two problems:

  1) providing connection between more than two TRILL sites that belong
     to a single TRILL network and are separated by an MPLS provider
     network using [RFC7173].  (Herein, this is also called "problem
     statement 1".)

  2) providing a single logical virtualized TRILL network for different
     tenants that are separated by an MPLS provider network.  In short,
     this is for providing connection between TRILL sites belonging to
     a tenant/tenants over a MPLS provider network.  (Herein, this is
     also called "problem statement 2".)

  A tenant is the administrative entity on whose behalf their
  associated services are managed.  Here, "tenant" refers to a TRILL
  campus that is segregated from other tenants for security reasons.

  A key multi-tenancy requirement is traffic isolation so that one
  tenant's traffic is not visible to any other tenant.  This document
  also addresses the problem of multi-tenancy by isolating one tenant's
  traffic from the other.

  [RFC7173] mentions how to interconnect a pair of TRILL switch ports
  using pseudowires.  This document explains how to connect multiple
  TRILL sites (not limited to only two sites) using the mechanisms and
  encapsulations defined in [RFC7173].

1.1.  Terminology

  Acronyms and terms used in this document include the following:

  AC         - Attachment Circuit [RFC4664]

  Data Label - VLAN Label or Fine-Grained Label




Umair, et al.                 Informational                     [Page 3]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  database   - IS-IS link state database

  ECMP       - Equal-Cost Multipath

  FGL        - Fine-Grained Labeling [RFC7172]

  IS-IS      - Intermediate System to Intermediate System [IS-IS]

  LAN        - Local Area Network

  MPLS       - Multiprotocol Label Switching

  PBB        - Provider Backbone Bridging

  PE         - Provider Edge device

  PSN        - Packet Switched Network

  PW         - Pseudowire [RFC4664]

  TIR        - TRILL Intermediate Router (Device that has both IP/MPLS
               and TRILL functionality)

  TRILL      - Transparent Interconnection of Lots of Links OR Tunneled
               Routing in the Link Layer

  TRILL site - A part of a TRILL campus that contains at least one
               RBridge.

  VLAN       - Virtual Local Area Network

  VPLS       - Virtual Private LAN Service

  VPTS       - Virtual Private TRILL Service

  VSI        - Virtual Service Instance [RFC4664]

  VTSD       - Virtual TRILL Switch Domain OR Virtual TRILL Service
               Domain.  A Virtual RBridge that segregates one tenant's
               TRILL database as well as traffic from the other.

  WAN       - Wide Area Network









Umair, et al.                 Informational                     [Page 4]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


2.  TRILL-over-MPLS Model

  TRILL over MPLS can be achieved in two different ways:
     a) the VPLS Model for TRILL b) the VPTS Model / TIR Model for
     TRILL

  Both these models can be used to solve problem statements 1 and 2.
  Herein, the VPLS Model for TRILL is also called "Model 1" and the
  VPTS Model / TIR Model is also called "Model 2".

3.  VPLS Model

  Figure 1 shows the topological model of TRILL over MPLS using the
  VPLS model.  The PE routers in the below topology model should
  support all the functional components mentioned in [RFC4664].

         +-----+                                               +-----+
         | RBa +---+      ...........................      +---| RBb |
         +-----+   |      .                         .      |   +-----+
         Site 1    |    +----+                   +----+    |    Site 2
                   +----|PE1 |                   |PE2 |----+
                        +----+    MPLS Cloud     +----+
                          .                         .
                          .         +----+          .
                          ..........|PE3 |...........
                                    +----+      ^
                                       |        |
                                       |        +-- Emulated LAN
                                    +-----+
                                    | RBc |
                                    +-----+
                                    Site 3

             Figure 1: Topological Model of TRILL over MPLS
                        Connecting 3 TRILL Sites

  Figure 2 below shows the topological model of TRILL over MPLS to
  connect multiple TRILL sites belonging to a tenant.  ("Tenant" here
  is a TRILL campus, not a specific Data Label.) VSI1 and VSI2 are two
  Virtual Service Instances that segregate Tenant1's traffic from other
  tenant traffic.  VSI1 will maintain its own database for Tenant1;
  similarly, VSI2 will maintain its own database for Tenant2.









Umair, et al.                 Informational                     [Page 5]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


     +-----+         ............................          +-----+
     |RBat1+---+     . ++++++++++++++++++++++++ .      +---|RBbt1|
     +-----+   |     . +                      + .      |   +-----+
     Tenant1   |    +----+                   +----+    |   Tenant1
     Site 1    +----|VSI1|                   |VSI1|----+   Site 2
               +----|VSI2|    MPLS  Cloud    |VSI2|----+
               |    +----+                   +----+    |
     +-----+   |     . +                       + .     |   +-----+
     |RBat2+---+     . +++++++++ +----+ ++++++++ .     +---|RBbt2|
     +-----+         ............|VSI1|...........         +-----+
     Tenant2                     |VSI2|                    Tenant2
     Site 1                      +----+                    Site 2
                                   |
                                +-----+
                                |RBct2|
                                +-----+
                            Tenant2 Site 3

        .... VSI1 Path
        ++++ VSI2 Path

                 Figure 2: Topological Model for VPLS Model
                   Connecting 2 Tenants with 3 Sites Each

  In this model, TRILL sites are connected to VPLS-capable PE devices
  that provide a logical interconnect, such that TRILL RBridges
  belonging to a specific tenant are connected via a single bridged
  Ethernet.  These PE devices are the same as the PE devices specified
  in [RFC4026].  The Attachment Circuit ports of PE routers are Layer 2
  switch ports that are connected to the RBridges at a TRILL site.
  Here, each VPLS instance looks like an emulated LAN.  This model is
  similar to connecting different RBridges by a Layer 2 bridge domain
  (multi-access link) as specified in [RFC6325].  This model doesn't
  requires any changes in PE routers to carry TRILL packets, as TRILL
  packets will be transferred transparently.

3.1.  Entities in the VPLS Model

  The PE (VPLS-PE) and Customer Edge (CE) devices are defined in
  [RFC4026].

  The generic L2VPN transport functional components like Attachment
  Circuits, pseudowires, VSI, etc., are defined in [RFC4664].

  The RB (RBridge) and TRILL campus are defined in [RFC6325] as updated
  by [RFC7780].





Umair, et al.                 Informational                     [Page 6]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


3.2.  TRILL Adjacency for VPLS Model

  As specified in Section 3, the MPLS cloud looks like an emulated LAN
  (also called multi-access link or broadcast link).  This results in
  RBridges at different sites looking like they are connected by a
  multi-access link.  With such interconnection, the TRILL adjacencies
  over the link are automatically discovered and established through
  TRILL IS-IS control messages [RFC7177].  These IS-IS control messages
  are transparently forwarded by the VPLS domain, after doing MPLS
  encapsulation as specified in Section 3.3.

3.3.  MPLS Encapsulation for VPLS Model

  Use of VPLS [RFC4762] [RFC4761] to interconnect TRILL sites requires
  no changes to a VPLS implementation -- in particular, the use of
  Ethernet pseudowires between VPLS PEs.  A VPLS PE receives normal
  Ethernet frames from an RBridge (i.e., CE) and is not aware that the
  CE is an RBridge device.  As an example, an MPLS-encapsulated TRILL
  packet within the MPLS network can use the format illustrated in
  Appendix A of [RFC7173] for the non-PBB case.  For the PBB case,
  additional header fields illustrated in [RFC7041] can be added by the
  entry PE and removed by the exit PE.

3.4.  Loop-Free Provider PSN/MPLS

  No explicit handling is required to avoid a loop-free topology.  The
  "split horizon" technique specified in [RFC4664] will take care of
  avoiding loops in the provider PSN network.

3.5.  Frame Processing

  The PE devices transparently process the TRILL control and data
  frames.  Procedures to forward the frames are defined in [RFC4664].

4.  VPTS Model

  The Virtual Private TRILL Service (VPTS) is a Layer 2 TRILL service
  that emulates TRILL service across a Wide Area Network (WAN).  VPTS
  is similar to what VPLS does for a bridged core but provides a TRILL
  core.  VPLS provides "Virtual Private LAN Service" for different
  customers.  VPTS provides "Virtual Private TRILL Service" for
  different TRILL tenants.

  Figure 3 shows the topological model of TRILL over MPLS using VPTS.
  In this model, the PE routers are replaced with TRILL Intermediate
  Routers (TIRs), and the VSIs are replaced with Virtual TRILL Switch
  Domains (VTSDs).  The TIR devices must be capable of supporting both




Umair, et al.                 Informational                     [Page 7]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  MPLS and TRILL as specified in Section 4.1.1.  The TIR devices are
  interconnected via PWs and appear as a unified emulated TRILL campus
  with each VTSD inside a TIR equivalent to an RBridge.

  Below are some of the reasons for interconnecting TRILL sites without
  isolating the TRILL control plane of one TRILL site from other sites.

  1) Nickname uniqueness: One of the basic requirements of TRILL is
     that RBridge nicknames are unique within the campus [RFC6325].  If
     we segregate the control plane of one TRILL site from other TRILL
     sites and provide interconnection between these sites, it may
     result in nickname collision.

  2) Distribution trees and their pruning: When a TRILL Data packet
     traverses a Distribution Tree, it will stay on it even in other
     TRILL sites.  If no end-station service is enabled for a
     particular Data Label in a TRILL site, the distribution tree may
     be pruned and TRILL data packets of that particular Data Label
     might never get to another TRILL site where the packets had no
     receivers.  The TRILL Reverse Path Forwarding (RPF) check will
     always be performed on the packets that are received by TIRs
     through pseudowires.

  3) Hop count values: When a TRILL data packet is received over a
     pseudowire by a TIR, the TIR does the processing of Hop Count
     defined in [RFC6325] and will not perform any resetting of Hop
     Count.

       +-----+                                               +-----+
       | RBa +---+      ...........................      +---| RBb |
       +-----+   |      .                         .      |   +-----+
       Site 1    |    +----+                   +----+    |    Site 2
                 +----|TIR1|                   |TIR2|----+
                      +----+    MPLS Cloud     +----+
                        .                         .
                        .         +----+          .
                        ..........|TIR3|...........
                                  +----+      ^
                                     |        |
                                     |        +-- Emulated TRILL
                                  +-----+
                                  | RBc |
                                  +-----+
                                  Site 3

      Figure 3: Topological Model of VPTS/TIR Connecting 3 TRILL Sites





Umair, et al.                 Informational                     [Page 8]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  In Figure 3, Site 1, Site 2, and Site 3 (running the TRILL protocol)
  are connected to TIR devices.  These TIR devices, along with the MPLS
  cloud, look like a unified emulated TRILL network.  Only the PE
  devices in the MPLS network should be replaced with TIRs so the
  intermediate provider routers are agnostic to the TRILL protocol.

  Figure 4 below extends the topological model of TRILL over MPLS to
  connect multiple TRILL sites belonging to a tenant ("tenant" here is
  a campus, not a Data Label) using the VPTS model.  VTSD1 and VTSD2
  are two Virtual TRILL Switch Domains (Virtual RBridges) that
  segregate Tenant1's traffic from Tenant2's traffic.  VTSD1 will
  maintain its own TRILL database for Tenant1; similarly, VTSD2 will
  maintain its own TRILL database for Tenant2.

      +-----+          ............................         +-----+
      |RBat1+---+      . ######################## .     +---|RBbt1|
      +-----+   |      . #                      # .     |   +-----+
      Tenant1   |    +-----+                 +-----+    |   Tenant1
      Site 1    +----|VTSD1|                 |VTSD1|----+   Site 2
                +----|VTSD2|   MPLS  Cloud   |VTSD2|----+
                |    +-----+                 +-----+    |
      +-----+   |      . #                       # .    |   +-----+
      |RBat2+---+      . #########+-----+######### .    +---|RBbt2|
      +-----+          ...........|VTSD1|...........        +-----+
      Tenant2                     |VTSD2|          ^        Tenant2
      Site 1                      +-----+          |        Site 2
                                     |             |
                                  +-----+          +-----Emulated
                                  |RBct2|                  TRILL
                                  +-----+
                               Tenant2 Site 3

          .... VTSD1 Connectivity
          #### VTSD2 Connectivity

                  Figure 4: Topological Model of VPTS/TIR
                  Connecting 2 Tenants with 3 TRILL Sites

4.1.  Entities in the VPTS Model

  The CE devices are defined in [RFC4026].

  The generic L2VPN transport functional components like Attachment
  Circuits, pseudowires, etc., are defined in [RFC4664].

  The RB (RBridge) and TRILL campus are defined in [RFC6325] as updated
  by [RFC7780].




Umair, et al.                 Informational                     [Page 9]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  This model introduces two new entities, TIR and VTSD, which are
  described below.

4.1.1.  TRILL Intermediate Router (TIR)

  The TIRs must be capable of running both VPLS and TRILL protocols.
  TIR devices are a superset of the VPLS-PE devices defined in
  [RFC4026] with the additional functionality of TRILL.  The VSI that
  provides transparent bridging functionality in the PE device is
  replaced with VTSD in a TIR.

4.1.2.  Virtual TRILL Switch/Service Domain (VTSD)

  The VTSD is similar to the VSI (Layer 2 bridge) in the VPLS model,
  but the VTSD acts as a TRILL RBridge.  The VTSD is a superset of the
  VSI and must support all the functionality provided by the VSI as
  defined in [RFC4026].  Along with VSI functionality, the VTSD must be
  capable of supporting TRILL protocols and forming TRILL adjacencies.
  The VTSD must be capable of performing all the operations that a
  standard TRILL switch can do.

  One VTSD instance per tenant must be maintained when multiple tenants
  are connected to a TIR.  The VTSD must maintain all the information
  kept by the RBridge on a per-tenant basis.  The VTSD must also take
  care of segregating one tenant's traffic from another's.  Each VTSD
  will have its own nickname for each tenant.  If a TIR supports 10
  TRILL tenants, it needs to be assigned with 10 TRILL nicknames, one
  for the nickname space of each of its tenants, and run 10 copies of
  TRILL protocols, one for each tenant.  It is possible that it would
  have the same nickname for two or more tenants, but, since the TRILL
  data and control traffic are separated for the tenants, there is no
  confusion.

4.2.  TRILL Adjacency for VPTS Model

  The VTSD must be capable of forming a TRILL adjacency with the
  corresponding VTSDs present in its peer VPTS neighbor and also with
  the neighboring RBridges of the TRILL sites.  The procedure to form
  TRILL adjacency is specified in [RFC7173] and [RFC7177].

4.3.  MPLS Encapsulation for VPTS Model

  The VPTS model uses PPP or Ethernet pseudowires for MPLS
  encapsulation as specified in [RFC7173] and requires no changes in
  the packet format in that RFC.  In accordance with [RFC7173], the PPP
  encapsulation is the default.





Umair, et al.                 Informational                    [Page 10]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


4.4.  Loop-Free Provider PSN/MPLS

  This model isn't required to employ the "split horizon" mechanism in
  the provider PSN network, as TRILL takes care of loop-free topology
  using distribution trees.  Any multi-destination packet will traverse
  a distribution tree path.  All distribution trees are calculated
  based on the TRILL base protocol standard [RFC6325] as updated by
  [RFC7780].

4.5.  Frame Processing

  This section specifies multi-destination and unicast frame processing
  in the VPTS/TIR model.

4.5.1.  Multi-destination Frame Processing

  Any multi-destination (unknown unicast, multicast, or broadcast, as
  indicated by the multi-destination bit in the TRILL header) packets
  inside a VTSD will be processed or forwarded through the distribution
  tree for which they were encapsulated on TRILL ingress.  If any
  multi-destination packet is received from the wrong pseudowire at a
  VTSD, the TRILL protocol running in the VTSD will perform an RPF
  check as specified in [RFC7780] and drop the packet.

  The pruning mechanism in distribution trees, as specified in
  [RFC6325] and [RFC7780], can also be used to avoid forwarding of
  multi-destination data packets on the branches where there are no
  potential destinations.

4.5.2.  Unicast Frame Processing

  Unicast packets are forwarded in the same way they get forwarded in a
  standard TRILL campus as specified in [RFC6325].  If multiple equal-
  cost paths are available over pseudowires to reach the destination,
  then VTSD should be capable of doing ECMP for those equal-cost paths.

5.  VPTS Model versus VPLS Model

  The VPLS model uses a simpler loop-breaking rule: the "split horizon"
  rule, where a PE must not forward traffic from one PW to another in
  the same VPLS mesh.  In contrast, the VPTS model uses distribution
  trees for loop-free topology.  As this is an emulated TRILL service,
  for interoperability purposes, the VPTS model is the default.








Umair, et al.                 Informational                    [Page 11]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


6.  Packet Processing between Pseudowires

  Whenever a packet gets received over a pseudowire, a VTSD will
  decapsulate the MPLS headers then check the TRILL header.  If the
  egress nickname in the TRILL header is for a TRILL site located
  beyond another pseudowire, then the VTSD will encapsulate the packet
  with new MPLS headers and send it across the proper pseudowire.

  For example, in Figure 3, consider that the pseudowire between TIR1
  and TIR2 fails.  Then, TIR1 will communicate with TIR2 via TIR3.
  Whenever packets that are destined to TIR3 are received from the
  pseudowire between TIR1 and TIR3, the VTSD inside TIR3 will
  decapsulate the MPLS headers, then check the TRILL header's egress
  nickname field.  If the egress nickname indicates it is destined for
  the RBridge in Site 3, then the packet will be sent to RBc; if the
  egress nickname is located at Site 2, VTSD will add MPLS headers for
  the pseudowire between TIR3 and TIR2 and forward the packet on that
  pseudowire.

7.  Efficiency Considerations

  Since the VPTS model uses distribution trees for processing of multi-
  destination data packets, it is always advisable to have at least one
  distribution tree root located in every TRILL site.  This will
  prevent data packets from being received at TRILL sites where end-
  station service is not enabled for that data packet.

8.  Security Considerations

  This document specifies methods using existing standards and
  facilities in ways that do not create new security problems.

  For general VPLS security considerations, including discussion of
  isolating customers from each other, see [RFC4761] and [RFC4762].

  For security considerations for transport of TRILL by pseudowires,
  see [RFC7173].  In particular, since pseudowires are supported by
  MPLS or IP, which are in turn supported by a link layer, that
  document recommends using IP security, such as IPsec [RFC4301] or
  DTLS [RFC6347], or the lower link-layer security, such as MACSEC
  [802.1AE] for Ethernet links.

  Transmission outside the customer environment through the provider
  environment, as described in this document, increases risk of
  compromise or injection of false data through failure of tenant
  isolation or by the provider.  In the VPLS model (Section 3), the use
  of link encryption and authentication between the CEs of a tenant
  that is being connected through provider facilities should be a good



Umair, et al.                 Informational                    [Page 12]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  defense.  In the VPTS model (Section 4), it is assumed that the CEs
  will peer with virtual TRILL switches of the provider network, and
  thus link security between TRILL switch ports is inadequate as it
  will terminate at the edge PE.  Thus, encryption and authentication
  from end station to end station and authentication are more
  appropriate for the VPTS model.

  For added security against the compromise of data, end-to-end
  encryption and authentication should be considered; that is,
  encryption and authentication from source end station to destination
  end station.  This would typically be provided by IPsec [RFC4301] or
  DTLS [RFC6347] or other protocols convenient to protect the
  information of concern.

  For general TRILL security considerations, see [RFC6325].

9.  IANA Considerations

  This document has no IANA actions.

10.  References

10.1.  Normative References

  [IS-IS]    ISO, "Intermediate system to Intermediate system routeing
             information exchange protocol for use in conjunction with
             the Protocol for providing the Connectionless-mode Network
             Service (ISO 8473)", ISO/IEC 10589:2002, 2002.

  [RFC4761]  Kompella, K., Ed., and Y. Rekhter, Ed., "Virtual Private
             LAN Service (VPLS) Using BGP for Auto-Discovery and
             Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
             <https://www.rfc-editor.org/info/rfc4761>.

  [RFC4762]  Lasserre, M., Ed., and V. Kompella, Ed., "Virtual Private
             LAN Service (VPLS) Using Label Distribution Protocol (LDP)
             Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
             <https://www.rfc-editor.org/info/rfc4762>.

  [RFC6325]  Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A.
             Ghanwani, "Routing Bridges (RBridges): Base Protocol
             Specification", RFC 6325, DOI 10.17487/RFC6325, July 2011,
             <https://www.rfc-editor.org/info/rfc6325>.








Umair, et al.                 Informational                    [Page 13]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  [RFC7173]  Yong, L., Eastlake 3rd, D., Aldrin, S., and J. Hudson,
             "Transparent Interconnection of Lots of Links (TRILL)
             Transport Using Pseudowires", RFC 7173,
             DOI 10.17487/RFC7173, May 2014,
             <https://www.rfc-editor.org/info/rfc7173>.

  [RFC7177]  Eastlake 3rd, D., Perlman, R., Ghanwani, A., Yang, H., and
             V. Manral, "Transparent Interconnection of Lots of Links
             (TRILL): Adjacency", RFC 7177, DOI 10.17487/RFC7177, May
             2014, <https://www.rfc-editor.org/info/rfc7177>.

  [RFC7780]  Eastlake 3rd, D., Zhang, M., Perlman, R., Banerjee, A.,
             Ghanwani, A., and S. Gupta, "Transparent Interconnection
             of Lots of Links (TRILL): Clarifications, Corrections, and
             Updates", RFC 7780, DOI 10.17487/RFC7780, February 2016,
             <https://www.rfc-editor.org/info/rfc7780>.

10.2.  Informative References

  [802.1AE]  IEEE, "IEEE Standard for Local and Metropolitan Area
             Networks: Media Access Control (MAC) Security", IEEE Std
             802.1AE, DOI 10.1109/IEEESTD.2006.245590.

  [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
             Private Network (VPN) Terminology", RFC 4026,
             DOI 10.17487/RFC4026, March 2005,
             <https://www.rfc-editor.org/info/rfc4026>.

  [RFC4301]  Kent, S. and K. Seo, "Security Architecture for the
             Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
             December 2005, <https://www.rfc-editor.org/info/rfc4301>.

  [RFC4664]  Andersson, L., Ed., and E. Rosen, Ed., "Framework for
             Layer 2 Virtual Private Networks (L2VPNs)", RFC 4664,
             DOI 10.17487/RFC4664, September 2006,
             <https://www.rfc-editor.org/info/rfc4664>.

  [RFC6347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
             Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
             January 2012, <https://www.rfc-editor.org/info/rfc6347>.

  [RFC7041]  Balus, F., Ed., Sajassi, A., Ed., and N. Bitar, Ed.,
             "Extensions to the Virtual Private LAN Service (VPLS)
             Provider Edge (PE) Model for Provider Backbone Bridging",
             RFC 7041, DOI 10.17487/RFC7041, November 2013,
             <https://www.rfc-editor.org/info/rfc7041>.





Umair, et al.                 Informational                    [Page 14]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


  [RFC7172]  Eastlake 3rd, D., Zhang, M., Agarwal, P., Perlman, R., and
             D. Dutt, "Transparent Interconnection of Lots of Links
             (TRILL): Fine-Grained Labeling", RFC 7172,
             DOI 10.17487/RFC7172, May 2014,
             <https://www.rfc-editor.org/info/rfc7172>.

Acknowledgements

  The contributions of Andrew G. Malis are gratefully acknowledged in
  improving the quality of this document.









































Umair, et al.                 Informational                    [Page 15]

RFC 8385          TRILL Transparent Transport over MPLS        June 2018


Authors' Addresses

  Mohammed Umair
  Cisco Systems
  SEZ, Cessna Business Park
  Sarjapur - Marathahalli Outer Ring road
  Bengaluru - 560103
  India

  Email: [email protected]


  S. Kingston Smiler
  PALC NETWORKS PVT LTD
  Envision Technology Center
  #119, 1st Floor, Road No.3
  EPIP Area Phase 1, Whitefield
  Near Vydehi Hospital
  Bengaluru - 560066, Karnataka
  India

  Email: [email protected]


  Donald Eastlake 3rd
  Huawei Technologies
  155 Beaver Street
  Milford, MA  01757
  United States of America

  Phone: +1-508-333-2270
  Email: [email protected]


  Lucy Yong
  Independent

  Phone: +1-469-227-5837
  Email: [email protected]












Umair, et al.                 Informational                    [Page 16]