TRILL WG                                                   Radia Perlman
Internet-Draft                                                  Dell EMC
Intended status: Standards Track                              Fangwei Hu
Expires: August 31, 2018                                 ZTE Corporation
                                                         Donald Eastlake
                                                               Ting Liao
                                                     Huawei Technologies
                                                            Feb 27, 2018

                          TRILL Smart Endnodes


   This draft addresses the problem of the size and freshness of the
   endnode learning table in edge RBridges, by allowing endnodes to
   volunteer for endnode learning and encapsulation/decapsulation.  Such
   an endnode is known as a "Smart Endnode".  Only the attached edge
   RBridge can distinguish a "Smart Endnode" from a "normal endnode".
   The smart endnode uses the nickname of the attached edge RBridge, so
   this solution does not consume extra nicknames.  The solution also
   enables Fine Grained Label aware endnodes.

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
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   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   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 August 31, 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

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   ( 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.  Conventions used in this document . . . . . . . . . . . . . .   3
     2.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
     2.2.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   3.  Solution Overview . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Smart-Hello Mechanism between Smart Endnode and RBridge . . .   5
     4.1.  Smart-Hello Encapsulation . . . . . . . . . . . . . . . .   5
     4.2.  Edge RBridge's Smart-Hello  . . . . . . . . . . . . . . .   7
     4.3.  Smart Endnode's Smart-Hello . . . . . . . . . . . . . . .   7
   5.  Data Packet Processing  . . . . . . . . . . . . . . . . . . .   8
     5.1.  Data Packet Processing for Smart Endnode  . . . . . . . .   8
     5.2.  Data Packet Processing for Edge RBridge . . . . . . . . .   9
   6.  Multi-homing Scenario . . . . . . . . . . . . . . . . . . . .  10
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .  11
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  12
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  12
     10.1.  Informative References . . . . . . . . . . . . . . . . .  12
     10.2.  Normative References . . . . . . . . . . . . . . . . . .  12
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

1.  Introduction

   The IETF TRILL (Transparent Interconnection of Lots of Links)
   protocol [RFC6325] [RFC7780] provides optimal pair-wise data frame
   forwarding without configuration, safe forwarding even during periods
   of temporary loops, and support for multipathing of both unicast and
   multicast traffic.  TRILL accomplishes this by using IS-IS [IS-IS]
   [RFC7176] link state routing and encapsulating traffic using a header
   that includes a hop count.  Devices that implement TRILL are called
   "RBridges" (Routing Bridges) or "TRILL Switches".

   An RBridge that attaches to endnodes is called an "edge RBridge" or
   "edge TRILL Switch", whereas one that exclusively forwards
   encapsulated frames is known as a "transit RBridge" or "transit TRILL
   Switch".  An edge RBridge traditionally is the one that encapsulates
   a native Ethernet frame with a TRILL header, or that receives a
   TRILL-encapsulated packet and decapsulates the TRILL header.  To

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   encapsulate efficiently, the edge RBridge must keep an "endnode
   table" consisting of (MAC, Data Label, TRILL egress switch nickname)
   sets, for those remote MAC addresses in Data Labels currently
   communicating with endnodes to which the edge RBridge is attached.

   These table entries might be configured, received from ESADI
   [RFC7357], looked up in a directory [RFC7067], or learned from
   decapsulating received traffic.  If the edge RBridge has attached
   endnodes communicating with many remote endnodes, this table could
   become very large.  Also, if one of the MAC addresses and Data Labels
   in the table has moved to a different remote TRILL switch, it might
   be difficult for the edge RBridge to notice this quickly, and because
   the edge RBridge is encapsulting to the incorrect egress RBridge, the
   traffic will get lost.

2.  Conventions used in this document

2.1.  Terminology

   Edge RBridge: An RBridge providing endnode service on at least one of
   its ports.  It is also called an edge TRILL Switch.

   Data Label: VLAN or FGL.

   DRB: Designated RBridge [RFC6325].

   ESADI: End Station Address Distribution Information [RFC7357].

   FGL: Fine Grained Label [RFC7172].

   IS-IS: Intermediate System to Intermediate System [IS-IS].

   RBridge: Routing Bridge, an alternative name for a TRILL switch.

   Smart Endnode: An endnode that has the capability specified in this
   document including learning and maintaining (MAC, Data Label,
   Nickname) entries and encapsulating/decapsulating TRILL frame.

   Transit RBridge: An RBridge exclusively forwards encapsulated frames.
   It is also named as transit RBridge.

   TRILL: Transparent Interconnection of Lots of Links

   TRILL ES-IS: TRILL End System to Intermediate System, is a variation
   of TRILL IS-IS designed to operate on a TRILL link among and between
   one or more TRILL switches and end stations on that link[RFC8171].

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   TRILL Switch: a device that implements the TRILL protocol; an
   alternative term for an RBridge.

2.2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  Solution Overview

   The Smart Endnode solution defined in this document addresses the
   problem of the size and freshness of the endnode learning table in
   edge RBridges.  An endnode E, attached to an edge RBridge R, tells R
   that E would like to be a "Smart Endnode", which means that E will
   encapsulate and decapsulate the TRILL frame, using R's nickname.
   Because E uses R's nickname, this solution does not consume extra

   Take the figure 1 as the example Smart Endnode scenario: RB1, RB2 and
   RB3 are the RBridges in the TRILL domain, and SE1 and SE2 are the
   smart endnodes which can encapsulate and decapsulate the TRILL
   packets.  RB1 is the edge RB and it is been attached by SE1 and SE2.
   RB1 assigns its nickname being used to SE1 and SE2.

   Each Smart Endnode, SE1 and SE2, uses RB1's nickname when
   encapsulating, and maintains an endnode table of (MAC, label, TRILL
   egress switch nickname) for remote endnodes that it (SE1 or SE2) is
   corresponding with.  RB1 does not decapsulate packets destined for
   SE1 or SE2, and does not learn (MAC, label, TRILL egress switch
   nickname) for endnodes corresponding with SE1 or SE2, but RB1 does
   decapsulate, and does learn (MAC, label, TRILL egress switch
   nickname) for any endnodes attached to RB1 that have not declared
   themselves to be Smart Endnodes.

   Just as an RBridge learns and times out (MAC, label, TRILL egress
   switch nickname), Smart Endnodes SE1 and SE2 also learn and time out
   endnode entries.  However, SE1 and SE2 might also determine, through
   ICMP messages or other techniques that an endnode entry is not
   successfully reaching the destination endnode, and can be deleted,
   even if the entry has not timed out.

   If SE1 wishes to correspond with destination MAC D, and no endnode
   entry exists, SE1 will encapsulate the packet as an unknown
   destination, or consulting a directory [RFC7067] (just as an RBridge
   would do if there was no endnode entry).

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  |SE1(Smart |
  |Endnode1) |  \      +------------------------------+
  +----------+   \    /                                \
                  \  /+------+   +------+    +-----+    \   +----------+
                  /-+-| RB 1 |---|  RB2 |----| RB3 |-----+--| Endnode1 |
                 /  | +------+   +------+    +-----+     |  +----------+
  +----------+ /     \                                  /
  |SE2(Smart |        \                                /
  | Endnode2)|         +------------------------------+
                     Figure 1 Smart Endnode Scenario

   The mechanism in this draft is that the Smart Endnode SE1 issues a
   Smart-Hello, indicating SE1's desire to act as a Smart Endnode,
   together with the set of MAC addresses and Data Labels that SE1 owns.
   The Smart-Hello is used to announce the Smart Endnode capability and
   parameters (such as MAC address, Data Label etc.).  The Smart-Hello
   is a type of TRILL ES-IS ,which is specified in section 5 of
   [RFC8171].  The detailed content for a smart endnode's Smart-Hello is
   defined in section 4.

   If RB1 supports having a Smart Endnode neighbor it also sends Smart-
   Hellos.  The smart endnode learns from RB1's Smart-Hellos what RB1's
   nickname is and which trees RB1 can use when RB1 ingresses multi-
   destination frames.  Although Smart Endnode SE1 transmits Smart-
   Hellos, it does not transmit or receive LSPs or E-L1FS FS-LSPs

   Since a Smart Endnode can encapsulate TRILL Data packets, it can
   cause the Inner.Lable to be a Fine Grained Label [RFC7172], thus this
   method supports FGL aware endnodes.  When and how a smart endnode
   decides to use the FGL instead of VLANs to encapsulate the TRILL Data
   packet is out of scope in this document.

4.  Smart-Hello Mechanism between Smart Endnode and RBridge

   The subsections below describe Smart-Hello messages.

4.1.  Smart-Hello Encapsulation

   Although a Smart Endnode is not an RBridge, does not send LSPs or
   maintain a copy of the link state database, and does not perform
   routing calculations, it is required to have a "Hello" mechanism (1)
   to announce to edge RBridges that it is a Smart Endnode and (2) to
   tell them what MAC addresses it is handling in what Data Labels.
   Similarly, an edge RBridge that supports Smart Endnodes needs a
   message (1) to announce that support, (2) to inform Smart Endnodes

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   what nickname to use for ingress and what nickname(s) can be used as
   egress nickname in a multi-destination TRILL Data packet, and (3) the
   list of smart end nodes it knows about on that link.

   The messages sent by Smart Endnodes and by edge RBridges that support
   Smart Endnodes are called "Smart-Hellos".  The Smart-Hello is a type
   of TRILL ES-IS, which is specified in [RFC8171].

   The Smart-Hello Payload, both for Smart-Hellos sent by Smart Endnodes
   and for Smart-Hellos sent by Edge RBridges, consists of TRILL IS-IS
   TLVs as described in the following two sub-sections.  The non-
   extended format is used so TLVs, sub-TLVs, and APPsub-TLVs have an
   8-bit size and type field.  Both types of Smart-Hellos MUST include a
   Smart-Parameters APPsub-TLV as follows inside a TRILL GENINFO TLV:

                 |Smart-Parameters|                 (1 byte)
                 |    Length      |                 (1 byte)
                 |        Holding Time           |  (2 bytes)
                 |             Flags             |  (2 bytes)

                   Figure 2 Smart Parameters APPsub-TLV

      Type: APPsub-TLV type Smart-Parameters, value is TBD1.

      Length: 4.

      Holding Time: A time in seconds as an unsigned integer.  It has
      the same meaning as the Holding Time field in IS-IS Hellos [IS-IS]
      . A Smart Endnode and an Edge RBridge supporting Smart Endndoes
      MUST send a Smart-Hello at least three times during their Holding
      Time.  If no Smart-Hellos is received from a Smart Endnode or Edge
      RBridge within the most recent Holding Time it sent, it is assumed
      that it is no longer available.

      Flags: At this time all of the Flags are reserved and MUST be send
      as zero and ignored on receipt.

   If more than one Smart Parameters APPsub-TLV appears in a Smart-
   Hello, the first one is used and any following ones are ignored.  If
   no Smart Parameters APPsub-TLV appears in a Smart-Hello, that Smart-
   Hello is ignored.

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4.2.  Edge RBridge's Smart-Hello

   The edge RBridge's Smart-Hello contains the following information in
   addition to the Smart-Parameters APPsub-TLV:

   o  RBridge's nickname.  The nickname sub-TLV, specified in section
      2.3.2 in [RFC7176], is reused here carried inside a TLV 242 (IS-IS
      router capability) in a Smart-Hello frame.  If more than one
      nickname appears in the Smart-Hello, the first one is used and the
      following ones are ignored.

   o  Trees that RB1 can use when ingressing multi-destination frames.
      The Tree Identifiers Sub-TLV, specified in section 2.3.4 in
      [RFC7176], is reused here.

   o  Smart Endnode neighbor list.  The TRILL Neighbor TLV, specified in
      section 2.5 in [RFC7176], is reused for this purpose.

   o  An Autentication TLV MAY also be included.

4.3.  Smart Endnode's Smart-Hello

   A new APPsub-TLV (Smart-MAC TLV) is defined for use by Smart Endnodes
   as defined below.  In addition, there will be a Smart-Parameters
   APPsub-TLV and there MAY be an Authentication TLV in a Smart Endnode

   If there are several VLANs/FGL Data Labels for that Smart Endnode,
   the Smart-MAC APPsub-TLV is included several times in Smart Endnode's
   Smart-Hello.  This APPsub-TLV appears inside a TRILL GENINFO TLV.

    |Type=Smart-MAC |                  (1 byte)
    |   Length      |                  (1 byte)
    | F |RSV | VLAN/FGL Data Label  |  (2 bytes or 4 bytes)
    |                          MAC (1)       (6 bytes)                 |
    |                      .................                           |
    |                          MAC (N)       (6 bytes)                 |

                     Figure 3 Smart-MAC APPsub-TLV

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   o  Type: TRILL APPsub-TLV Type Smart-MAC, value is TBD2.

   o  Length: Total number of bytes contained in the value field.

   o  F: 1 bit.  If it sets to 1, which indicates that the endnode
      supports FGL data label, otherwise, the VLAN/FGL Data Labels
      [RFC7172] and that this Smart-MAC APPsub-TLV has an FGL in the
      following VLAN/FGL field.  Otherwise, the VLAN/FGL Data Label
      field is a VLAN ID.

   o  RSV: 2 bits or 6 bits, is reserved for the future use.  If VLAN/
      FGL Data Label indicates the VLAN ID(F flag sets to 0), the RESV
      field is 2 bits long.  Otherwise it is 6 bits.

   o  VLAN/FGL Data Label: This carries a 12-bits VLAN identifier or
      24-bits FGL Data Label that is valid for all subsequent MAC
      addresses in this APPsub-TLV, or the value zero if no VLAN/FGL
      data label is specified.

   o  MAC(i): This is a 48-bit MAC address reachable in the Data Label
      given from the Smart Endnode that is announcing this APPsub-TLV.

5.  Data Packet Processing

   The subsections below specify Smart Endnode data packet processing.
   All TRILL Data packets sent to or from Smart Endnodes are sent in the
   Designated VLAN [RFC6325] of the local link but do not necessarily
   have to be VLAN tagged.

5.1.  Data Packet Processing for Smart Endnode

   A Smart Endnode does not issue or receive LSPs or E-L1FS FS-LSPs or
   calculate topology.  It does the following:

   o  Smart Endnode maintains an endnode table of (the MAC address of
      remote endnode, Data Label, the nickname of the edge RBridge's
      attached) entries of end nodes with which the Smart Endnode is
      communicating.  Entries in this table are populated the same way
      that an edge RBridge populates the entries in its table:

      *  learning from (source MAC address ingress nickname) on packets
         it decapsulates.

      *  by querying a directory [RFC7067].

      *  by having some entries configured.

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   o  When Smart Endnode SE1 wishes to send unicast frame to remote node
      D, if (MAC address of remote endnode D, Data Label, nickname)
      entry is in SE1's endnode table, SE1 encapsulates the ingress
      nickname as the nicknamae of the RBridge(RB1), egress nickname as
      indicated in D's table entry.  If D is unknown, SE1 either queries
      a directory or encapsulates the packet as a multi-destination
      frame, using one of the trees that RB1 has specified in RB1's
      Smart-Hello.  The mechanism for querying a directory is given in

   o  When SE1 wishes to send a a multi-destination (multicast, unknown
      unicast, or broadcast) to the TRILL campus, SE1 encapsulates the
      packet using one of the trees that RB1 has specified.

   If the Smart Endnode SE1 sends a multi-destination TRILL Data packet,
   the destination MAC of the outer Ethernet is All-RBridges multicast

   The Smart Endnode SE1 need not send Smart-Hellos as frequently as
   normal RBridges.  These Smart-Hellos could be periodically unicast to
   the Appointed Forwarder RB1.  In case RB1 crashes and restarts, or
   the DRB changes and SE1 receives the Smart-Hello without mentioning
   SE1, SE1 SHOULD send a Smart-Hello immediately.  If RB1 is Appointed
   Forwarder for any of the VLANs that SE1 claims, RB1 MUST list SE1 in
   its Smart-Hellos as a Smart Endnode neighbor.

5.2.  Data Packet Processing for Edge RBridge

   The attached edge RBridge processes and forwards TRILL Data packets
   based on the endnode property rather than for encapsulation and
   forwarding the native frames the same way as the traditional
   RBridges.  There are several situations for the edge RBridges as

   o  If receiving an encapsulated unicast TRILL Data packet from a port
      with a Smart Endnode, with RB1's nickname as ingress, the edge
      RBridge RB1 forwards the frame to the specified egress nickname,
      as with any encapsulated frame.  However, RB1 MAY filter the
      encapsulation frame based on the inner source MAC and Data Label
      as specified for the Smart Endnode.  If the MAC (or Data Label)
      are not among the expected entries of the Smart Endnode, the frame
      would be dropped by the edge RBridge.

   o  If receiving a unicast TRILL Data packet with RB1's nickname as
      egress from the TRILL campus, and the destination MAC address in
      the enclosed packet is listed as "smart endnode", RB1 leaves the
      packet encapsulated when forwarding to the smart endnode, and both
      the outer and inner Ethernet destination MAC is the destination

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      smart endnode's MAC address, and the outer Ethernet source MAC
      address is the RB1's port MAC address.  The edge RBridge still
      decreases the Hop count value by 1, for there is one hop between
      the RB1 and Smart Endnode.

   o  If receiving an multi-destination TRILL Data packet from a port
      with a Smart Endnode, RBridge RB1 forwards the TRILL encapsulation
      to the TRILL campus based on the distribution tree indicated by
      the egress nickname.  If the egress nickname does not correspond
      to a distribution tree, the packet is discarded.  If there are any
      normal endnodes (i.e, non-Smart Endnodes) attached to the edge
      RBridge RB1, RB1 decapsulates the frame and sends the native frame
      to these ports possibly pruned based on multicast listeners, in
      addition to forwarding the multi-destination TRILL frame to the
      rest of the campus.

   o  If RB1 receives a native multi-destination data frame, which is
      sent by a non-smart endnode, from a port, including hybrid
      endnodes (smart endnodes and non-smart endnodes), RB1 will
      encapsulate it as multi-destination TRILL Data packet , and send
      the encapsulated multi-destination TRILL Data Packet out that same
      port to the smart endnodes attached to the port, and also send the
      encapsulated multi-destination TRILL Data Packet to the TRILL
      campus through other ports .

   o  If RB1 receives a multi-destination TRILL Data packet from a
      remote RBridge, and the exit port includes hybrid endnodes(Smart
      Endnodes and non-Smart Endnodes), it sends two copies of multicast
      frames out the port, one as native and the other as TRILL
      encapsulated frame.  When Smart Endnode receives multi-destination
      TRILL Data packet, it learns the remote (MAC address, Data Label,
      Nickname) entry, A Smart Endnodes ignores native data frames.  A
      normal (non-smart) endnode receives the native frame and learns
      the remote MAC address and ignores the TRILL data packet.  This
      transit solution may bring some complexity for the edge RBridge
      and waste network bandwidth resource, so avoiding the hybrid
      endnodes scenario by attaching the Smart Endnodes and non-Smart
      Endnodes to different ports is RECOMMENDED.

6.  Multi-homing Scenario

   Multi-homing is a common scenario for the Smart Endnode.  The Smart
   Endnode is on a link attached to the TRILL domain in two places: to
   edge RBridge RB1 and RB2.  Take the figure below as example.  The
   Smart Endnode SE1 is attached to the TRILL domain by RB1 and RB2
   separately.  Both RB1 and RB2 could announce their nicknames to SE1.

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                        . .....................
                        .  +------+           .
                        .  | RB1  |           .
                        . /+------+           .
           +----------+ ./            +-----+ .    +----------+
           |SE1(Smart |/.             | RB3 |......| Smart    |
           | Endnode1)| .\            +-----+ .    | Endnode2 |
           +----------+ . \                   .    +----------+
                        .  +-----+            .
                        .  | RB2 |   TRILL    .
                        .  +-----+   Domain   .

                          Figure 4 Multi-homing Scenario

   Smart Endnode SE1 can choose either RB1 or RB2's nickname, when
   encapsulating and forwarding a TRILL data packet.  If the active-
   active load balance is considered for the multi-homing scenario, the
   Smart Endnode SE1 could use both RB1 and RB2's nickname to
   encapsulate and forward TRILL Data packet.  SE1 uses RB1's nickname
   when forwarding through RB1, and RB2's nickname when forwarding
   through RB2. this will cause MAC flip-flopping(see [RFC7379]) of the
   endnode table entry in the remote RBridges (or Smart Endnodes).  The
   solution for the MAC flip-flopping issue is to set a multi- homing
   bit in the RSV field of the TRILL data packet.  When remote RBridge
   RB3 or Smart Endnodes receives a data packet with the multi-homed bit
   set, the endnode entries (SE1's MAC address, label, RB1's nickname)
   and (SE1's MAC address, label, RB2's nickname) will coexist as
   endnode entries in the remote RBridge.  Another solution is to use
   the ESADI protocol to distribute multiple attachments of a MAC
   address of a multi-homing group,The ESADI is deployed among the edge
   RBridges (See section 5.3 of [RFC7357]).

7.  Security Considerations

   Smart-Hellos can be secured by using Authentication TLVs based on

   For general TRILL Security Considerations, see [RFC6325].

   For TRILL ES-IS Security Considerations, see [RFC8171].

8.  IANA Considerations

   IANA is requested to allocate APPsub-TLV type numbers for the Smart-
   MAC and Smart-Parameters APPsub-TLVs from the range below 256 and

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   update the "TRILL APPsub-TLV Types under IS-IS TLV 251 Application
   Identifier 1" registry as follows.

           |  Protocol |    Description    |    Reference     |
           |    TBD1   |  Smart-Parameters | [this document]  |
           |    TBD2   |     Smart-MAC     | [this document]  |

                                  Table 1

9.  Acknowledgements

   The contributions of the following persons are gratefully
   acknowledged: Mingui Zhang, Weiguo Hao, Linda Dunbar, Kesava Vijaya
   Krupakaran, and Andrew Qu.

10.  References

10.1.  Informative References

   [RFC7067]  Dunbar, L., Eastlake 3rd, D., Perlman, R., and I.
              Gashinsky, "Directory Assistance Problem and High-Level
              Design Proposal", RFC 7067, DOI 10.17487/RFC7067, November
              2013, <>.

   [RFC7379]  Li, Y., Hao, W., Perlman, R., Hudson, J., and H. Zhai,
              "Problem Statement and Goals for Active-Active Connection
              at the Transparent Interconnection of Lots of Links
              (TRILL) Edge", RFC 7379, DOI 10.17487/RFC7379, October
              2014, <>.

10.2.  Normative References

   [IS-IS]    ISO/IEC 10589:2002, Second Edition,, "Intermediate System
              to Intermediate System Intra-Domain Routing Exchange
              Protocol for use in Conjunction with the Protocol for
              Providing the Connectionless-mode Network Service (ISO
              8473)", 2002.

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

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   [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, <>.

   [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,

   [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,

   [RFC7176]  Eastlake 3rd, D., Senevirathne, T., Ghanwani, A., Dutt,
              D., and A. Banerjee, "Transparent Interconnection of Lots
              of Links (TRILL) Use of IS-IS", RFC 7176,
              DOI 10.17487/RFC7176, May 2014,

   [RFC7357]  Zhai, H., Hu, F., Perlman, R., Eastlake 3rd, D., and O.
              Stokes, "Transparent Interconnection of Lots of Links
              (TRILL): End Station Address Distribution Information
              (ESADI) Protocol", RFC 7357, DOI 10.17487/RFC7357,
              September 2014, <>.

   [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,

   [RFC8171]  Eastlake 3rd, D., Dunbar, L., Perlman, R., and Y. Li,
              "Transparent Interconnection of Lots of Links (TRILL):
              Edge Directory Assistance Mechanisms", RFC 8171,
              DOI 10.17487/RFC8171, June 2017,

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <>.

Perlman, et al.          Expires August 31, 2018               [Page 13]

Internet-Draft            TRILL Smart Endnodes                  Feb 2018

Authors' Addresses

   Radia Perlman
   Dell EMC
   176 South Street
   Hopkinton, MA  01748

   Phone: +1-206-291-367

   Fangwei Hu
   ZTE Corporation
   No.889 Bibo Rd
   Shanghai  201203

   Phone: +86 21 68896273

   Donald Eastlake
   Huawei Technologies
   155 Beaver Street
   Milford, MA 01757

   Phone: +1-508-634-2066

   Ting Liao
   Huawei Technologies
   Nanjing, Jiangsu  210012


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