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<rfc xmlns:xi="http://www.w3.org/2001/XInclude" category="std" docName="draft-ietf-isis-l2bundles-07.txt" consensus="true"
     number="9999" ipr="trust200902" obsoletes=""
     updates="" submissionType="IETF" xml:lang="en" tocInclude="true"
     symRefs="true" sortRefs="true" version="3">
  <!-- xml2rfc v2v3 conversion 2.23.0 -->
  <front>
    <title abbrev="isis-l2bundles">Advertising abbrev="ISIS L2 Bundles">Advertising L2 Bundle Member Link
    Attributes in IS-IS</title>
    <seriesInfo name="Internet-Draft" value="draft-ietf-isis-l2bundles-07.txt"/> name="RFC" value="9999"/>
    <author fullname="Les Ginsberg" initials="L" surname="Ginsberg">
      <organization>Cisco Systems</organization>
      <address>
        <postal>
          <street>510 McCarthy Blvd.</street>
          <city>Milpitas</city>
          <code>95035</code>
          <region>CA</region>
          <country>USA</country>
        </postal>
        <email>ginsberg@cisco.com</email>
      </address>
    </author>
    <author fullname="Ahmed Bashandy" initials="A" surname="Bashandy">
      <organization>Cisco Systems</organization>
      <address>
        <postal>
          <street>170 West Tasman Drive</street>
          <city>San Jose</city>
          <code>95134</code>
          <region>Ca</region>
          <country>US</country>
        </postal>
      </address>
    </author>
    <author fullname="Clarence Filsfils" initials="C" surname="Filsfils">
      <organization>Cisco Systems</organization>
      <address>
        <postal>
          <street/>
          <city/>
          <code/>
          <region/>
          <country/>
        </postal>
        <email>cf@cisco.com</email>
      </address>
    </author>
    <author fullname="Mohan Nanduri" initials="M" surname="Nanduri">
      <organization>eBay</organization>
      <address>
        <postal>
          <street/>
          <city/>
          <code/>
          <country/>
        </postal>
        <email>mnanduri@ebay.com</email>
      </address>
    </author>
    <author fullname="Ebben Aries" initials="E" surname="Aries">
      <organization>Private Contributer</organization>
      <address>
        <postal>
          <street/>
          <city/>
          <code/>
          <country/>
        </postal>
        <email>exa@dscp.org</email>
      </address>
    </author>
    <date day="25" month="May" year="2017"/> month="July" year="2019"/>
    <area>Routing Area</area>
    <workgroup>Networking Working Group</workgroup>
    <keyword>Sample</keyword>
    <abstract>
      <t>There are deployments where the Layer 3 interface on which IS-IS
      operates is a Layer 2 interface bundle. Existing IS-IS advertisements
      only support advertising link attributes of the Layer 3 interface. If
      entities external to IS-IS wish to control traffic flows on the
      individual physical links which comprise the Layer 2 interface bundle
      link attribute information about the bundle members is required.</t>
      <t>This document introduces the ability for IS-IS to advertise the link
      attributes of layer 2 (L2) bundle members.</t>
    </abstract>
    <note>
      <name>Requirements Language</name>
      <t>The
        <t>
    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
      "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL
    NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
    "<bcp14>MAY</bcp14>", and "OPTIONAL" "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
    described in RFC 2119 [RFC2119].</t> BCP&nbsp;14 <xref target="RFC2119"/> <xref target="RFC8174"/>
    when, and only when, they appear in all capitals, as shown here.
        </t>
    </note>
  </front>
  <middle>
    <section numbered="true" toc="default">
      <name>Introduction</name>
      <t>There are deployments where the Layer 3 interface on which an IS-IS
      adjacency is established is a Layer 2 interface bundle, for instance a
      Link Aggregation Group (LAG) [IEEE802.1AX]. <xref target="IEEE802.1AX"/>. This reduces the number of
      adjacencies which need to be maintained by the routing protocol in cases
      where there are parallel links between the neighbors. Entities external
      to IS-IS such as Path Computation Elements (PCE) [RFC4655] <xref target="RFC4655"/> may wish to
      control traffic flows on individual members of the underlying Layer 2
      bundle. In order to do so link attribute information about individual
      bundle members is required. The protocol extensions defined in this
      document provide the means to advertise this information.</t>
      <t>This document introduces a new TLV to advertise link attribute
      information for each of the L2 bundle members which comprise the Layer 3
      interface on which IS-IS operates.</t>
      <t>[SR-ISIS]
      <t><xref target="SR-ISIS"/> introduces a new link attribute - adjacency segment
      identifier (Adj-SID) - which can be used as an instruction to forwarding
      to send traffic over a specific link. This document introduces
      additional sub-TLVs to advertise Adj-SIDs for L2 Bundle members.</t>
      <t>Note that the new advertisements defined in this document are
      intended to be provided to external (to IS-IS) entities. The following
      items are intentionally not defined and/or are outside the scope of this
      document:</t>
      <ul spacing="normal">
        <li>What link attributes will be advertised. This is determined by
          the needs of the external entities.</li>
        <li>A minimum or default set of link attributes.</li>
        <li>How these attributes are configured</li>
        <li>How the advertisements are used</li>
        <li>What impact the use of these advertisements may have on traffic
          flow in the network</li>
        <li>How the advertisements are passed to external entities</li>
      </ul>
    </section>
    <section numbered="true" toc="default">
      <name>L2 Bundle Member Attributes TLV</name>
      <t>A new TLV is introduced to advertise L2 Bundle member attributes.
      Although much of the information is identical to and uses the same
      sub-TLVs included in Extended IS-Neighbor advertisements (TLVs 22 and
      222), a new TLV is used so that changes to the advertisement of the L2
      Bundle member link attributes does not trigger unnecessary action by the
      [ISO10589]
      <xref target="ISO10589"/> Decision process.</t>
      <t>Advertisement of this information implies that the identified link is
      a member of the L2 Bundle associated with the identified Parent L3
      Neighbor and that the member link is operationally up. Therefore
      advertisements MUST <bcp14>MUST</bcp14> be withdrawn if the link becomes operationally down
      or it is no longer a member of the identified L2 Bundle.</t>
      <t>This new TLV utilizes the sub-TLV space defined for TLVs 22, 23, 141,
      222, and 223.</t>
      <t>The following new TLV is introduced:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[    L2

<ul empty="true" spacing="normal">
<li><t>L2 Bundle Member Attributes
    Type: Attributes</t>
<ul empty="true">
<li>Type: 25 (suggested - to be assigned by IANA)
    Length: IANA)</li>
<li>Length: Number of octets to follow

    Parent follow</li>
</ul>
</li>
</ul>

<ul empty="true">
<li><t>Parent L3 Neighbor Descriptor
     L3 Descriptor</t>
<ul empty="true">
 <li>L3 Neighbor System ID + pseudonode ID (7 octets)
     Flags: octets)</li>
 <li><t>Flags: 1 octet field of following flags: flags:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
          0 1 2 3 4 5 6 7
         +-+-+-+-+-+-+-+-+
         |P|             |
         +-+-+-+-+-+-+-+-+

        where:

        P-flag: When
      ]]></artwork>

  <t>where:</t>

<dl><dt>P-flag:</dt>
<dd>When set to 1 one of the sub-TLVs described in Section 2.1 immediately
follows the flags field. If the P-flag is set to 0, then none of the sub-TLVs
described in Section 2.1 are present.

        Other bits: MUST present.</dd>
<dt>Other bits:</dt>
<dd><bcp14>MUST</bcp14> be zero when originated and ignored when
         received.

   One received.</dd>
</dl>
  </li>
</ul>
</li>
</ul>

<ul empty="true">
<li><t>One or more of the following:
    L2 following:</t>
 <ul empty="true">
 <li><t>L2 Bundle Attribute Descriptors
      Length Descriptors</t>
  <ul empty="true">
  <li><t>Length of L2 Bundle Attribute Descriptor (1 octet)
        NOTE: octet)</t>
   <ul empty="true">
   <li>NOTE: This includes all fields described below.

      Number below.</li>
   </ul>
      <t>Number of L2 Bundle Member Descriptors (1 octet)
      L2 octet)</t>
      <t>L2 Bundle Member Link Local Identifiers
        (4 Identifiers</t>
      <ul empty="true">
      <li>(4 * Number of L2 Bundle Member Descriptors octets)

        NOTE: octets)</li>
      <li>NOTE: An L2 Bundle Member Descriptor is a Link Local Identifier as
      defined in [RFC4202].

      sub-TLV(s)

      A <xref target="RFC4202"/>.</li>
      </ul>
      <t>sub-TLV(s)</t>
      <t>A sub-TLV may define an attribute common to all of
      the bundle members listed or a sub-TLV may define an
      attribute unique to each bundle member. Use of these
      two classes of sub-TLVs is described in the following
      sections.

]]></artwork>
      <t>NOTE:
      sections.</t>
  </li>
  </ul>
 </li>
 </ul>
</li>
</ul>

      <aside><t>NOTE: Only one Parent L3 Neighbor Descriptor is present in a
      given TLV. Multiple L2 Bundle Attribute Descriptors may be present in a
      single TLV.</t> TLV.</t></aside>

      <section numbered="true" toc="default">
        <name>Parallel L3 Adjacencies</name>
        <t>When there exist multiple L3 adjacencies to the same neighbor
        additional information is required to uniquely identify the L3
        Neighbor. One and only one of the following three sub-TLVs is used to
        uniquely identify the L3 adjacency:</t>
        <ul spacing="normal">
          <li>IPv4 Interface Address (sub-TLV 6 defined in [RFC5305])</li> <xref target="RFC5305"/>)</li>
          <li>IPv6 Interface Address (sub-TLV 12 defined in [RFC6119])</li> <xref target="RFC6119"/>)</li>
          <li>Link Local/Remote Identifiers (sub-TLV 4 defined in
            [RFC5307])</li>
            <xref target="RFC5307"/>)</li>
        </ul>
        <t>When the P-bit is set in the flags field in the Parent L3 Neighbor
        Descriptor one and only one of the above sub-TLVs MUST <bcp14>MUST</bcp14> be present. The
        chosen sub-TLV MUST <bcp14>MUST</bcp14> immediately follow the flags field described in
        Section 2.</t>
        <t>These sub-TLVs MAY <bcp14>MAY</bcp14> be omitted if no parallel adjacencies to the
        neighbor exist.</t>
      </section>
      <section numbered="true" toc="default">
        <name>Shared Attribute sub-TLVs</name>
        <t>These sub-TLVs advertise a single copy of an attribute (e.g. link
        bandwidth). The attribute applies to all of the L2 Bundle Members in
        the set advertised under the preceding  L2 Bundle Member
        Attribute Descriptor. No more than one copy of a given sub-TLV in this
        category may appear in the set of sub-TLVs under the preceding L2
        Bundle Member Attribute Descriptor. If multiple copies of a given
        sub-TLV are present all copies MUST <bcp14>MUST</bcp14> be ignored.</t>
        <t>The set of L2 Bundle Member Descriptors which may be advertised
        under a single L2 Bundle Member Attribute Descriptor is therefore
        limited to bundle members which share the set of attributes advertised
        in the shared attribute sub-TLVs.</t>
        <t>All existing sub-TLVs defined in the IANA Sub-TLVs for TLVs 22, 23,
        141, 222, and 223 registry are in the category of shared attribute
        sub-TLVs unless otherwise specified in this document.</t>
      </section>
    </section>
    <section numbered="true" toc="default">
      <name>Advertising L2 Bundle Member Adj-SIDs</name>
      <t>[SR-ISIS]
      <t><xref target="SR-ISIS"/> defines sub-TLVs to advertise Adj-SIDs for L3 adjacencies.
      However these sub-TLVs only support a advertisement of a single Adj-SID.
      As it is expected that each L2 Bundle member will have unique Adj-SIDs
      in many deployments it is desirable to define a new sub-TLV which allows
      more efficient encoding of a set of Adj-SIDs in a single sub-TLV. Two
      new sub-TLVs are therefore introduced to support advertising Adj-SIDs
      for L2 Bundle members. The format of the new sub-TLVs is similar to that
      used for L3 adjacencies, but is optimized to allow advertisement of a
      set of Adj-SIDs (one per L2 Bundle Member) in a single sub-TLV.</t>
      <t>The two new sub-TLVs defined in the following sections do not fall
      into the category of shared attribute sub-TLVs.</t>

      <section numbered="true" toc="default">
        <name>L2 Bundle Member Adjacency Segment Identifier sub-TLV</name>
        <t>This sub-TLV is used to advertise Adj-SIDs for L2 Bundle Members
        associated with a parent L3 adjacency which is Point-to-Point. The
        following format is defined for this sub-TLV:</t>
        <artwork name="" type="" align="left" alt=""><![CDATA[     Type:

<ul empty="true" spacing="normal">
<li><t>Type: 41 (suggested value to be assigned by IANA) (1 octet)
     Length: octet)</t></li>
<li><t>Length: variable (1 octet)

     Flags: octet)</t></li>

<li><t>Flags: 1 octet field of following flags: flags:</t>

<artwork name="" type="" align="left" alt=""><![CDATA[
          0 1 2 3 4 5 6 7
         +-+-+-+-+-+-+-+-+
         |F|*|V|L|S|P|   |
         +-+-+-+-+-+-+-+-+

        where:

         NOTE:
]]></artwork>
</li>
</ul>

<!-- SG: Moved <aside> up because I couldn't figure out how to get it to
appear correctly AND get the right indentation.
-->

         <aside><t>NOTE: The flags are deliberately kept congruent to the flags
         in the L3 ADJ-SID defined in [SR-ISIS]. <xref target="SR-ISIS" />.
         * indicates a flag used in the L3 Adj-SID sub-TLV but which is
         NOT used in this sub-TLV. These bits SHOULD <bcp14>SHOULD</bcp14> be sent as 0 and
         MUST
         <bcp14>MUST</bcp14> be ignored on receipt.

         F-Flag: Address-Family receipt.</t></aside>

<ul empty="true" spacing="normal">
<li><t>where:</t>

<dl spacing="normal">
<dt>F-Flag:</dt>
<dd>Address-Family flag.  If unset, then the Adj-SID refers
         to an L2 Bundle Member with outgoing IPv4 encapsulation. If set
         then the Adj-SID refers to an L2 Bundle Member with outgoing
         IPv6 encapsulation.

         V-Flag: Value encapsulation.</dd>

<dt>V-Flag:</dt>
<dd>Value flag.  If set, then the Adj-SID carries a value.
         By default the flag is SET.

         L-Flag: Local SET.</dd>

<dt>L-Flag:</dt>
<dd>Local Flag.  If set, then the value/index carried by
         the Adj-SID has local significance.  By default the flag is
         SET.

         S-Flag.  Set
         SET.</dd>

<dt>S-Flag.</dt>
<dd>Set Flag.  When set, the S-Flag indicates that the
         Adj-SID refers to a set of L2 Bundle Members (and therefore
         MAY
         <bcp14>MAY</bcp14> be assigned to other L2 Bundle Members as well).

         P-Flag.  Persistent well).</dd>

<dt>P-Flag.</dt>
<dd>Persistent flag.  When set, the P-Flag indicates that
         the Adj-SID is persistently allocated, i.e., the Adj-SID value
         remains consistent across router restart and/or interface flap.

         Other bits: MUST flap.</dd>

<dt>Other bits:</dt>
<dd><bcp14>MUST</bcp14> be zero when originated and ignored when
         received.

    Weight: 1
         received.</dd>
</dl>
</li>
      </ul>

<dl>
<dt>Weight:</dt>
<dd>1 octet.  The value represents the weight of the Adj-SID
        for the purpose of load balancing.  The use of the weight is
        defined in [SR-ARCH].

    NOTE: <xref target="RFC8402"/>.</dd>
</dl>

<aside><t>NOTE: Flags and weight are shared by all L2 Bundle Members
    listed in the L2 Bundle Attribute Descriptor.

    L2 Descriptor.</t></aside>

<dl>
<dt>L2 Bundle Member Adj-SID Descriptors. There MUST Descriptors.</dt>
<dd><t>There <bcp14>MUST</bcp14> be one descriptor
     for each of the L2 Bundle Members advertised under the preceding
     L2 Bundle Member Attribute Descriptor. Each descriptor consists
     of one of the following fields:

      SID/Index/Label: according fields:</t>

  <dl>
  <dt>SID/Index/Label:</dt>
  <dd><t>according to the V and L flags, it contains
        either:

        *  A
        either:</t>

    <ul empty="true" spacing="normal">
    <li>A 3 octet local label where the 20 rightmost bits are used
           for encoding the label value.  In this case the V and L
           flags MUST <bcp14>MUST</bcp14> be set.

        *  A set.</li>

    <li>A 4 octet index defining the offset in the SID/Label space
           advertised by this router. See [SR-ISIS]. <xref target="SR-ISIS"/>.
           In this case V and L flags MUST <bcp14>MUST</bcp14> be unset.

]]></artwork> unset.</li>
    </ul>
</dd>
  </dl>
</dd>
</dl>

      </section>
      <section numbered="true" toc="default">
        <name>L2 Bundle Member LAN Adjacency Segment Identifier sub-TLV</name>
        <t>This sub-TLV is used to advertise Adj-SIDs for L2 Bundle Members
        associated with a parent L3 adjacency which is a LAN adjacency. In LAN
        subnetworks, the Designated Intermediate System (DIS) is elected and
        originates the Pseudonode-LSP (PN-LSP) including all neighbors of the
        DIS. When Segment Routing is used, each router in the LAN MAY <bcp14>MAY</bcp14>
        advertise the Adj-SID of each of its neighbors on the LAN. Similarly,
        for each L2 Bundle Member a router MAY <bcp14>MAY</bcp14> advertise an Adj-SID to each
        neighbor on the LAN.</t>
        <t>The following format is defined for this sub-TLV:</t>
        <artwork name="" type="" align="left" alt=""><![CDATA[     Type:

<t>Type: 42 (suggested value to be assigned by IANA) (1 octet)
     Length: octet)</t>
<t>Length: variable (1 octet)
     Neighbor octet)</t>
<t>Neighbor System ID: 6 octets

     Flags: octets</t>

<ul empty="true" spacing="normal">
<li><t>Flags: 1 octet field of following flags: flags:</t>

<artwork name="" type="" align="left" alt=""><![CDATA[
          0 1 2 3 4 5 6 7
         +-+-+-+-+-+-+-+-+
         |F|*|V|L|S|P|   |
         +-+-+-+-+-+-+-+-+

        where:

         NOTE:
]]></artwork>
</li>
</ul>

         <aside><t>NOTE: The flags are deliberately kept congruent to the flags
         in the L3 LAN_ADJ-SID defined in [SR-ISIS]. <xref target="SR-ISIS"/>.
         * indicates a flag used in the L3 Adj-SID sub-TLV but which is
         NOT used in this sub-TLV. These bits SHOULD <bcp14>SHOULD</bcp14> be sent as 0 and
         MUST
         <bcp14>MUST</bcp14> be ignored on receipt.

         F-Flag: Address-Family receipt.</t></aside>

<ul empty="true" spacing="normal">
<li><t>where:</t>

<dl>
<dt>F-Flag:</dt>
<dd>Address-Family flag.  If unset, then the Adj-SID refers
         to an L2 Bundle Member with outgoing IPv4 encapsulation. If set
         then the Adj-SID refers to an L2 Bundle Member with outgoing
         IPv6 encapsulation.

         V-Flag: Value encapsulation.</dd>

<dt>V-Flag:</dt>
<dd>Value flag.  If set, then the Adj-SID carries a value.
         By default the flag is SET.

         L-Flag: Local SET.</dd>

<dt>L-Flag:</dt>
<dd>Local Flag.  If set, then the value/index carried by
         the Adj-SID has local significance.  By default the flag is
         SET.

         S-Flag.  Set
         SET.</dd>

<dt>S-Flag.</dt>
<dd>Set Flag.  When set, the S-Flag indicates that the
         Adj-SID refers to a set of L2 Bundle Members (and therefore
         MAY
         <bcp14>MAY</bcp14> be assigned to other L2 Bundle Members as well).

         P-Flag.  Persistent well).</dd>

<dt>P-Flag.</dt>
<dd>Persistent flag.  When set, the P-Flag indicates that
         the Adj-SID is persistently allocated, i.e., the Adj-SID value
         remains consistent across router restart and/or interface flap.

         Other bits: MUST flap.</dd>

<dt>Other bits:</dt>
<dd><bcp14>MUST</bcp14> be zero when originated and ignored when
         received.

    Weight: 1
         received.</dd>
</dl>
</li>
</ul>

<dl>
<dt>Weight:</dt>
<dd>1 octet.  The value represents the weight of the Adj-SID
    for the purpose of load balancing.  The use of the weight is
    defined in [SR-ARCH].

    NOTE: <xref target="RFC8402"/>.</dd>
</dl>

    <aside><t>NOTE: Flags and weight are shared by all L2 Bundle Members
    listed in the L2 Bundle Attribute Descriptor.

    L2 Descriptor.</t></aside>

<dl>
<dt>L2 Bundle Member LAN Adj-SID Descriptors. There MUST Descriptors.</dt>
<dd><t>There <bcp14>MUST</bcp14> be one
    descriptor for each of the L2 Bundle Members advertised
    under the preceding L2 Bundle Member Attribute Descriptor.
    Each descriptor consists of one of the following fields:

      SID/Index/Label: according fields:</t>
<dl>
<dt>SID/Index/Label:</dt>
<dd><t>according to the V and L flags, it contains
        either:

        *  A
        either:</t>
<ul><li>A 3 octet local label where the 20 rightmost bits are used
           for encoding the label value.  In this case the V and L
           flags MUST <bcp14>MUST</bcp14> be set.

        *  A set.</li>

    <li>A 4 octet index defining the offset in the SID/Label space
           advertised by this router. See [SR-ISIS]. <xref target="SR-ISIS"/>.
           In this case V and L flags MUST <bcp14>MUST</bcp14> be unset.

]]></artwork> unset.</li>
</ul>
</dd>
</dl>
</dd>
</dl>

      </section>
    </section>
    <section anchor="IANA" numbered="true" toc="default">
      <name>IANA Considerations</name>
      <t>This document adds the following new TLV to the IS-IS TLV Codepoints
      registry.</t>
      <t>Value:
<ul empty="true">
<li><t>Value: 25 (suggested - to be assigned by IANA)</t>
      <t>Name: IANA)</t></li>
<li><t>Name: L2 Bundle Member Attributes</t> Attributes</t></li>
</ul>
      <t>The name of the Sub-TLVs for TLVs 22, 23, 141, 222, and 223 registry
      needs to be changed to Sub-TLVs for TLVs 22, 23, 25, 141, 222, and 223
      registry. An additional column needs to be added to the registry to
      indicate which sub-TLVs may appear in the new L2 Bundle Member
      Attributes TLV. The column for TLV 25 has one of the following three
      values:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[y - sub-TLV

<dl>
 <dt>y:</dt>
 <dd>sub-TLV may appear in TLV 25 but MUST <bcp14>MUST</bcp14> NOT be shared by multiple
    L2 Bundle Members
y(s) - sub-TLV Members</dd>

 <dt>y(s):</dt>
 <dd>sub-TLV may appear in TLV 25 and MAY <bcp14>MAY</bcp14> be shared by multiple
    L2 Bundle Members
n - sub-TLV MUST Members</dd>

 <dt>n:</dt>
 <dd>sub-TLV <bcp14>MUST</bcp14> NOT appear in TLV 25]]></artwork> 25</dd>
</dl>
      <t>The following table indicates the appropriate settings for all
      currently defined sub-TLVs as regards their use in the new L2 Bundle
      Member Attributes TLV.</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[    3 Administrative

<table anchor="iana-table">
<name>Appropriate Settings for All Defined Sub-TLVs as regards their use in
the new L2 Bundle Member Attributes TLV</name>
  <thead>
      <tr>
	<th>Type</th>
	<th>Description</th>
	<th>25</th>
      </tr>
    </thead>
    <tbody>
      <tr>
	<td>3</td>
	<td>Administrative group (color) y(s)
    4 Link (color)</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>4</td>
	<td>Link Local/Remote Identifiers y(s)
    6 IPv4 Identifiers</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>6</td>
	<td>IPv4 interface address y(s)
    8 IPv4 address</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>8</td>
	<td>IPv4 neighbor address y(s)
    9 Maximum address</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>9</td>
	<td>Maximum link bandwidth y(s)
    10 Maximum bandwidth</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>10</td>
	<td>Maximum reservable link bandwidth y(s)
    11 Unreserved bandwidth y(s)
    12 IPv6 bandwidth</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>11</td>
	<td>Unreserved bandwidth</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>12</td>
	<td>IPv6 Interface Address y(s)
    13 IPv6 Address</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>13</td>
	<td>IPv6 Neighbor Address y(s)
    14 Extended Address</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>14</td>
	<td>Extended Administrative Group y(s)
    18 TE Group</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>18</td>
	<td>TE Default metric y(s)
    19 Link-attributes y(s)
    20 Link metric</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>19</td>
	<td>Link-attributes</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>20</td>
	<td>Link Protection Type y(s)
    21 Interface Type</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>21</td>
	<td>Interface Switching Capability Descriptor y(s)
    22 Bandwidth Constraints y(s)
    23 Unconstrained Descriptor</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>22</td>
	<td>Bandwidth Constraints</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>23</td>
	<td>Unconstrained TE LSP Count y(s)
    24 Remote Count</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>24</td>
	<td>Remote AS number n
    25 IPv4 number</td>
	<td>n</td>
      </tr>
      <tr>
	<td>25</td>
	<td>IPv4 remote ASBR Identifier n
    26 IPv6 Identifier</td>
	<td>n</td>
      </tr>
      <tr>
	<td>26</td>
	<td>IPv6 remote ASBR Identifier n
    27 Interface Identifier</td>
	<td>n</td>
      </tr>
      <tr>
	<td>27</td>
	<td>Interface Adjustment Capability Descriptor (IACD) y(s)
    28 MTU n
    29 SPB-Metric y(s)
    30 SPB-A-OALG y(s)
    33 Unidirectional (IACD)</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>28</td>
	<td>MTU n</td>
	<td>n</td>
      </tr>
      <tr>
	<td>29</td>
	<td>SPB-Metric</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>30</td>
	<td>SPB-A-OALG</td>
	<td>y(s)</td>
      </tr>
      <tr>
	<td>33</td>
	<td>Unidirectional Link Delay y
    34 Min/Max Delay</td>
	<td>y</td>
      </tr>
      <tr>
	<td>34</td>
	<td>Min/Max Unidirectional Link Delay</td>
	<td>y</td>
      </tr>
      <tr>
	<td>35</td>
	<td>Unidirectional Delay y
    35 Unidirectional Delay Variation y
    36 Unidirectional Variation</td>
	<td>y</td>
      </tr>
      <tr>
	<td>36</td>
	<td>Unidirectional Link Loss y
    37 Unidirectional Loss</td>
	<td>y</td>
      </tr>
      <tr>
	<td>37</td>
	<td>Unidirectional Residual Bandwidth y
    38 Unidirectional Bandwidth</td>
	<td>y</td>
      </tr>
      <tr>
	<td>38</td>
	<td>Unidirectional Available Bandwidth y
    39 Unidirectional Bandwidth</td>
	<td>y</td>
      </tr>
      <tr>
	<td>39</td>
	<td>Unidirectional Utilized Bandwidth y
    40 RTM Capability n

]]></artwork> Bandwidth</td>
	<td>y</td>
      </tr>
      <tr>
	<td>40</td>
	<td>RTM Capability</td>
	<td>n</td>
      </tr>
    </tbody>
      </table>

      <t>This document adds the following new sub-TLVs to the sub-TLVs for
      TLVs 22, 23, 25, 141, 222, and 223 registry.</t>
      <t>Value:
<ul empty="true">
 <li><t>Value: 41 (suggested - to be assigned by IANA)</t>
      <t>Name: IANA)</t></li>
 <li><t>Name: L2 Bundle Member Adj-SID</t>
      <t>This Adj-SID</t></li>
 <li><t>This sub-TLV is allowed in the following TLVs:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[ 22 23 25 141 222 223
 n  n  y   n   n   n
]]></artwork>
      <t>Value: TLVs:</t></li>
</ul>

<table anchor="table2">
  <thead>
      <tr>
        <th>22</th>
	<th>23</th>
        <th>25</th>
        <th>141</th>
        <th>222</th>
        <th>223</th>
      </tr>
  </thead>
    <tbody>
      <tr>
        <td>n</td>
        <td>n</td>
        <td>y</td>
        <td>n</td>
        <td>n</td>
        <td>n</td>
      </tr>
    </tbody>
</table>

<ul empty="true">
 <li><t>Value: 42 (suggested to be assigned by IANA)</t>
      <t>Name: IANA)</t></li>
 <li><t>Name: L2 Bundle Member LAN Adj-SID</t>
      <t>This Adj-SID</t></li>
 <li><t>This sub-TLV is allowed in the following TLVs:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[ 22 23 25 141 222 223
 n  n  y   n   n   n
]]></artwork> TLVs:</t></li>
</ul>

<table anchor="table3">
  <thead>
      <tr>
        <th>22</th>
        <th>23</th>
        <th>25</th>
        <th>141</th>
        <th>222</th>
        <th>223</th>
      </tr>
  </thead>
    <tbody>
      <tr>
        <td>n</td>
        <td>n</td>
        <td>y</td>
        <td>n</td>
        <td>n</td>
        <td>n</td>
      </tr>
    </tbody>
</table>

    </section>
    <section anchor="Security" numbered="true" toc="default">
      <name>Security Considerations</name>
      <t>The IS-IS protocol has supported the advertisement of link attribute
      information, including link identifiers, for many years. The
      advertisements defined in this document are identical to existing
      advertisements defined in [RFC4202], [RFC5305], [RFC7810], <xref target="RFC4202"/>, <xref
      target="RFC5305"/>, <xref target="RFC7810"/>, and [SR-ISIS] <xref target="SR-ISIS"/>
      - but are associated with L2 links which are part of a bundle interface
      on which the IS-IS protocol operates. There are therefore no new
      security issues introduced by the extensions in this document.</t>
      <t>As always, if the protocol is used in an environment where
      unauthorized access to the physical links on which IS-IS PDUs are sent
      occurs then attacks are possible. The use of authentication as defined
      in [RFC5304] <xref target="RFC5304"/> and [RFC5310] <xref target="RFC5310"/> is recommended to prevent such attacks.</t>
    </section>

    <section numbered="true" toc="default">
      <name>Contributors</name>
      <t>The following people gave a substantial contribution to the content
      of this document and should be considered as co-authors:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[Stefano alt=""><![CDATA[
Stefano Previdi
Cisco Systems
Via Del Serafico 200
Rome  0144
Italy

Email: sprevidi@cisco.com]]></artwork>
    </section>
    <section anchor="Acknowledgements" numbered="true" toc="default">
      <name>Acknowledgements</name>
      <t>The authors would like to thank Jon Mitchell for his careful
      review.</t>
    </section>
  </middle>
  <back>
    <references>
      <name>References</name>
      <references>
        <name>Normative References</name>
        <reference anchor="ISO10589">
          <front>
            <title>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)</title>
            <seriesInfo name="ISO/IEC" value="10589:2002, Second Edition"/>
            <author>
              <organization abbrev="ISO">International Organization for
            Standardization</organization>
            </author>
            <date month="Nov" year="2002"/>
          </front>
        </reference>
        <reference anchor="IEEE802.1AX">
          <front>
            <title>IEEE Standard for Local and Metropolitan Area Networks - Link
          Aggregation.</title>
            <author>
              <organization abbrev="IEEE">Institute of Electrical and
            Electronics Engineers</organization>
            </author>
            <date month="Nov" year="2008"/>
          </front>
        </reference>

<reference anchor="SR-ISIS"> anchor='SR-ISIS'>
<front>
<title>IS-IS Extensions for Segment Routing,
          draft-ietf-isis-segment-routing-extensions-12(work in
          progress)</title> Routing</title>

<author fullname="Previdi S., et al,"/>
            <date month="April" year="2017"/>
          </front>
        </reference>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <seriesInfo name="DOI" value="10.17487/RFC2119"/>
            <seriesInfo name="RFC" value="2119"/>
            <seriesInfo name="BCP" value="14"/> initials='S' surname='Previdi' fullname='Stefano Previdi'>
    <organization />
</author>

<author initials="S." surname="Bradner" fullname="S. Bradner">
              <organization/>
            </author>
            <date year="1997" month="March"/>
            <abstract>
              <t>In many standards track documents several words are used to signify the requirements in the specification.  These words are often capitalized. This document defines these words as they should be interpreted in IETF documents.  This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC4202" target="https://www.rfc-editor.org/info/rfc4202">
          <front>
            <title>Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)</title>
            <seriesInfo name="DOI" value="10.17487/RFC4202"/>
            <seriesInfo name="RFC" value="4202"/>
            <author initials="K." surname="Kompella" fullname="K. Kompella" role="editor">
              <organization/>
            </author>
            <author initials="Y." surname="Rekhter" fullname="Y. Rekhter" role="editor">
              <organization/>
            </author>
            <date year="2005" month="October"/>
            <abstract>
              <t>This document specifies routing extensions in support of carrying link state information for Generalized Multi-Protocol Label Switching (GMPLS).  This document enhances the routing extensions required to support MPLS Traffic Engineering (TE).  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC5304" target="https://www.rfc-editor.org/info/rfc5304">
          <front>
            <title>IS-IS Cryptographic Authentication</title>
            <seriesInfo name="DOI" value="10.17487/RFC5304"/>
            <seriesInfo name="RFC" value="5304"/>
            <author initials="T." surname="Li" fullname="T. Li">
              <organization/>
            </author>
            <author initials="R." surname="Atkinson" fullname="R. Atkinson">
              <organization/>
            </author>
            <date year="2008" month="October"/>
            <abstract>
              <t>This document describes the authentication of Intermediate System to Intermediate System (IS-IS) Protocol Data Units (PDUs) using the Hashed Message Authentication Codes - Message Digest 5 (HMAC-MD5) algorithm as found in RFC 2104.  IS-IS is specified in International Standards Organization (ISO) 10589, with extensions to support Internet Protocol version 4 (IPv4) described in RFC 1195.  The base specification includes an authentication mechanism that allows for multiple authentication algorithms.  The base specification only specifies the algorithm for cleartext passwords.  This document replaces RFC 3567.</t>
              <t>This document proposes an extension to that specification that allows the use of the HMAC-MD5 authentication algorithm to be used in conjunction with the existing authentication mechanisms.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC5305" target="https://www.rfc-editor.org/info/rfc5305">
          <front>
            <title>IS-IS Extensions for Traffic Engineering</title>
            <seriesInfo name="DOI" value="10.17487/RFC5305"/>
            <seriesInfo name="RFC" value="5305"/>
            <author initials="T." surname="Li" fullname="T. Li">
              <organization/>
            </author>
            <author initials="H." surname="Smit" fullname="H. Smit">
              <organization/>
            </author>
            <date year="2008" month="October"/>
            <abstract>
              <t>This document describes extensions to the Intermediate System to Intermediate System (IS-IS) protocol to support Traffic Engineering (TE).  This document extends the IS-IS protocol by specifying new information that an Intermediate System (router) can place in Link State Protocol Data Units (LSP).  This information describes additional details regarding the state of the network that are useful for traffic engineering computations.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC5307" target="https://www.rfc-editor.org/info/rfc5307">
          <front>
            <title>IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)</title>
            <seriesInfo name="DOI" value="10.17487/RFC5307"/>
            <seriesInfo name="RFC" value="5307"/>
            <author initials="K." surname="Kompella" fullname="K. Kompella" role="editor">
              <organization/>
            </author>
            <author initials="Y." surname="Rekhter" fullname="Y. Rekhter" role="editor">
              <organization/>
            </author>
            <date year="2008" month="October"/>
            <abstract>
              <t>This document specifies encoding of extensions to the IS-IS routing protocol in support of Generalized Multi-Protocol Label Switching (GMPLS).  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC5310" target="https://www.rfc-editor.org/info/rfc5310">
          <front>
            <title>IS-IS Generic Cryptographic Authentication</title>
            <seriesInfo name="DOI" value="10.17487/RFC5310"/>
            <seriesInfo name="RFC" value="5310"/>
            <author initials="M." surname="Bhatia" fullname="M. Bhatia">
              <organization/>
            </author>
            <author initials="V." surname="Manral" fullname="V. Manral">
              <organization/>
            </author>
            <author initials="T." surname="Li" fullname="T. Li">
              <organization/>
            </author>
            <author initials="R." surname="Atkinson" fullname="R. Atkinson">
              <organization/>
            </author>
            <author initials="R." surname="White" fullname="R. White">
              <organization/>
            </author>
            <author initials="M." surname="Fanto" fullname="M. Fanto">
              <organization/>
            </author>
            <date year="2009" month="February"/>
            <abstract>
              <t>This document proposes an extension to Intermediate System to Intermediate System (IS-IS) to allow the use of any cryptographic authentication algorithm in addition to the already-documented authentication schemes, described in the base specification and RFC 5304.  IS-IS is specified in International Standards Organization (ISO) 10589, with extensions to support Internet Protocol version 4 (IPv4) described in RFC 1195.</t>
              <t>Although this document has been written specifically for using the Hashed Message Authentication Code (HMAC) construct along with the Secure Hash Algorithm (SHA) family of cryptographic hash functions, the method described in this document is generic and can be used to extend IS-IS to support any cryptographic hash function in the future.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC6119" target="https://www.rfc-editor.org/info/rfc6119">
          <front>
            <title>IPv6 Traffic Engineering in IS-IS</title>
            <seriesInfo name="DOI" value="10.17487/RFC6119"/>
            <seriesInfo name="RFC" value="6119"/>
            <author initials="J." surname="Harrison" fullname="J. Harrison">
              <organization/>
            </author>
            <author initials="J." surname="Berger" fullname="J. Berger">
              <organization/>
            </author>
            <author initials="M." surname="Bartlett" fullname="M. Bartlett">
              <organization/>
            </author>
            <date year="2011" month="February"/>
            <abstract>
              <t>This document specifies a method for exchanging IPv6 traffic  engineering information using the IS-IS routing protocol. This information enables routers in an IS-IS network to  calculate traffic-engineered routes using IPv6 addresses. [STANDARDS-TRACK]</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="RFC7810" target="https://www.rfc-editor.org/info/rfc7810">
          <front>
            <title>IS-IS Traffic Engineering (TE) Metric Extensions</title>
            <seriesInfo name="DOI" value="10.17487/RFC7810"/>
            <seriesInfo name="RFC" value="7810"/>
            <author initials="S." surname="Previdi" fullname="S. Previdi" role="editor">
              <organization/>
            </author>
            <author initials="S." surname="Giacalone" fullname="S. Giacalone">
              <organization/>
            </author>
            <author initials="D." surname="Ward" fullname="D. Ward">
              <organization/>
            </author>
            <author initials="J." surname="Drake" fullname="J. Drake">
              <organization/> initials='L' surname='Ginsberg' fullname='Les Ginsberg'>
    <organization />
</author>

<author initials="Q." surname="Wu" fullname="Q. Wu">
              <organization/> initials='C' surname='Filsfils' fullname='Clarence Filsfils'>
    <organization />
</author>
            <date year="2016" month="May"/>
            <abstract>
              <t>In certain networks, such as, but not limited to, financial information networks (e.g., stock market data providers), network- performance criteria (e.g., latency) are becoming as critical to data-path selection as other metrics.</t>
              <t>This document describes extensions to IS-IS Traffic Engineering Extensions (RFC 5305) such that network-performance information can be distributed and collected in a scalable fashion.  The information distributed using IS-IS TE Metric Extensions can then be used to make path-selection decisions based on network performance.</t>
              <t>Note that this document only covers the mechanisms with which network-performance information is distributed.  The mechanisms for measuring network performance or acting on that information, once distributed, are outside the scope of this document.</t>
            </abstract>
          </front>
        </reference>
      </references>
      <references>
        <name>Informational References</name>
        <reference anchor="RFC4655" target="https://www.rfc-editor.org/info/rfc4655">
          <front>
            <title>A Path Computation Element (PCE)-Based Architecture</title>
            <seriesInfo name="DOI" value="10.17487/RFC4655"/>
            <seriesInfo name="RFC" value="4655"/>

<author initials="A." surname="Farrel" fullname="A. Farrel">
              <organization/> initials='A' surname='Bashandy' fullname='Ahmed Bashandy'>
    <organization />
</author>

<author initials="J.-P." surname="Vasseur" fullname="J.-P. Vasseur">
              <organization/> initials='H' surname='Gredler' fullname='Hannes Gredler'>
    <organization />
</author>

<author initials="J." surname="Ash" fullname="J. Ash">
              <organization/> initials='B' surname='Decraene' fullname='Bruno Decraene'>
    <organization />
</author>

<date year="2006" month="August"/>
            <abstract>
              <t>Constraint-based path computation is a fundamental building block for traffic engineering systems such as Multiprotocol Label Switching (MPLS) and Generalized Multiprotocol Label Switching (GMPLS) networks.  Path computation in large, multi-domain, multi-region, or multi-layer networks is complex and may require special computational components and cooperation between the different network domains.</t>
              <t>This document specifies the architecture month='May' day='19' year='2019' />

<abstract><t>Segment Routing (SR) allows for a Path Computation Element (PCE)-based model to address this problem space.  This document does not attempt to provide a detailed description flexible definition of all end-to-end paths within IGP topologies by encoding paths as sequences of topological sub-paths, called "segments".  These segments are advertised by the architectural components, but rather it link-state routing protocols (IS-IS and OSPF).  This draft describes a set of building blocks for the PCE architecture from which solutions may necessary IS-IS extensions that need to be constructed.  This memo provides information introduced for the Internet community.</t>
            </abstract>
          </front>
        </reference>
        <reference anchor="SR-ARCH">
          <front>
            <title>Segment Segment Routing Architecture,
          draft-ietf-spring-segment-routing-11(work in progress)</title>
            <author fullname="Filsfils C., et al,"/>
            <date month="February" year="2017"/> operating on an MPLS data-plane.</t></abstract>

</front>

<seriesInfo name='Work in Progress' value='draft-ietf-isis-segment-routing-extensions-25' />
<format type='TXT'
        target='http://www.ietf.org/internet-drafts/draft-ietf-isis-segment-routing-extensions-25.txt' />
</reference>

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4202.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5304.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5305.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5307.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.5310.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6119.xml"/>
<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.7810.xml"/>
      </references>

      <references>
        <name>Informational References</name>

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8402.xml"/>

<xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4655.xml"/>

      </references>
    </references>
    <section numbered="true" toc="default">
      <name>Example Encoding</name>
      <t/>
      <t>Below is an example encoding of L2 Bundle advertisements in a case
      where we have two parallel adjacencies to the same neighbor whose
      system-id is 1234.1234.1234.00. The two L2 bundles have the following
      sets of attributes:</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[L3

<t>L3 Adjacency #1
L3 #1</t>
<t>L3 IPv4 local link address: 192.0.2.1
Four 192.0.2.1</t>
<t>Four bundle members with the following attributes:

--------------------------------------------------
Num | Link attributes:</t>

<table anchor="table4">
  <thead>
      <tr>
        <th>Num</th>
        <th>Link Local ID | Bandwidth | Adj-SID/Weight |
--------------------------------------------------
1   | 0x11111111    | 1G        | 0x11111/1      |
--------------------------------------------------
2   | 0x11112222    | 1G        | 0x11112/1      |
--------------------------------------------------
3   | 0x11113333    | 10G       | 0x11113/1      |
--------------------------------------------------
4   | 0x11114444    | 10G       | 0x11114/1      |
--------------------------------------------------

L3 ID</th>
        <th>Bandwidth</th>
        <th>Adj-SID/Weight</th>
      </tr>
  </thead>
    <tbody>
<tr>
<td>1</td>
<td>0x11111111</td>
<td>1G</td>
<td>0x11111/1</td>
</tr>

<tr>
<td>2</td>
<td>0x11112222</td>
<td>1G</td>
<td>0x11112/1</td>
</tr>

<tr>
<td>3</td>
<td>0x11113333</td>
<td>10G</td>
<td>0x11113/1</td>
</tr>

<tr>
<td>4</td>
<td>0x11114444</td>
<td>10G</td>
<td>0x11114/1</td>
</tr>
</tbody>
</table>

<t>L3 Adjacency #2
L3 #2</t>
<t>L3 IPv4 local link address: 192.0.2.2
Three 192.0.2.2</t>
<t>Three bundle members with the following attributes:

--------------------------------------------------
Num | Link attributes:</t>

<table anchor="table5">
  <thead>
      <tr>
        <th>Num</th>
        <th>Link Local ID | Bandwidth | Adj-SID/Weight |
--------------------------------------------------
1   | 0x22221111    | 10G       | 22221/1        |
--------------------------------------------------
2   | 0x22222222    | 10G       | 22222/1        |
--------------------------------------------------
3   | 0x22223333    | 10G       | 22223/1        |
--------------------------------------------------
]]></artwork> ID</th>
        <th>Bandwidth</th>
        <th>Adj-SID/Weight</th>
      </tr>
  </thead>
    <tbody>
<tr>
<td>1</td>
<td>0x22221111</td>
<td>10G</td>
<td>22221/1</td>
</tr>

<tr>
<td>2</td>
<td>0x22222222</td>
<td>10G</td>
<td>22222/1</td>
</tr>

<tr>
<td>3</td>
<td>0x22223333</td>
<td>10G</td>
<td>22223/1</td>
</tr>
</tbody>
</table>

      <t>This requires two TLVs, one for each L3 adjacency.</t>
      <t>TLV
      <t><strong>TLV for Adjacency #1:</t> #1:</strong></t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 0                   1
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Type(25)     |Len: 64        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Parent
]]></artwork>

<t>Parent L3 Neighbor Descriptor Descriptor</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor System-ID octets 1-4: 1234.1234                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| System-ID octets 5-6: 1234    | P-node: 00    |1|0|0|0|0|0|0|0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

IPv4
]]></artwork>

<t>IPv4 Interface Address sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 0                   1
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Type(6))     | Length(4)     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 address:192.0.2.1                                          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Attribute Descriptors Descriptors</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Len:9+6+10 = 25| # Desc: 2     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #1: 0x11111111            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #2: 0x11112222            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Maximum
]]></artwork>

<t>Maximum Link Bandwidth sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(9)       | Length(4)    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Value: 1G/8                                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Member Adjacency Segment Identifier sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(41)     | Length(8)     |0|0|1|1|0|0|0|0| Weight: 1     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #1: 0x11111         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #2: 0x11112         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Attribute Descriptors Descriptors</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Len:9+6+10 = 25| # Desc: 2     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #3: 0x11113333            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #4: 0x11114444            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Maximum
]]></artwork>

<t>Maximum Link Bandwidth sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(9)       | Length(4)    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Value: 10G/8                                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Member Adjacency Segment Identifier sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(41)     | Length(8)     |0|0|1|1|0|0|0|0| Weight: 1     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #3: 0x11113         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #4: 0x11114         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
]]></artwork>
      <t>TLV

      <t><strong>TLV for Adjacency #2</t> #2</strong></t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
0                   1
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Type(25)     | Len: 46       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Parent
]]></artwork>

<t>Parent L3 Neighbor Descriptor Descriptor</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Neighbor System-ID octets 1-4: 1234.1234                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| System-ID octets 5-6: 1234    | P-node: 00    |1|0|0|0|0|0|0|0|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

IPv4
]]></artwork>

<t>IPv4 Interface Address sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 0                   1
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Type(6))     | Length(4)     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IPv4 address: 192.0.2.2                                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Attribute Descriptors Descriptors</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Len:13+6+13=32 | # Desc: 3     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #1: 0x22221111            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #2: 0x22222222            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Local Identifier Bundle Member #3: 0x22223333            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Maximum
]]></artwork>

<t>Maximum Link Bandwidth sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(9)       | Length(4)    |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Bandwidth Value: 10G/8                                        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

L2
]]></artwork>

<t>L2 Bundle Member Adjacency Segment Identifier sub-TLV sub-TLV</t>
      <artwork name="" type="" align="left" alt=""><![CDATA[
 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(41)     | Length(11)    |0|0|1|1|0|0|0|0| Weight: 1     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #1: 0x22221         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #2: 0x22222         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Local Label Bundle Member #3: 0x22223         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
]]></artwork>
    </section>
  </back>
</rfc>