< draft-ietf-trill-multi-topology-05.txt   mt132fftoc.txt 
INTERNET-DRAFT Donald Eastlake INTERNET-DRAFT Donald Eastlake
Intended status: Proposed Standard Mingui Zhang Intended status: Proposed Standard Mingui Zhang
Updates: 6325, 7177 Huawei Huawei
Ayan Banerjee Ayan Banerjee
Cisco Cisco
Expires: May 11, 2018 November 12, 2017 Expires: September 7, 2018 March 8, 2018
TRILL: Multi-Topology TRILL: Multi-Topology
<draft-ietf-trill-multi-topology-05.txt> <draft-ietf-trill-multi-topology-06.txt>
Abstract Abstract
This document specifies extensions to the IETF TRILL (Transparent This document specifies extensions to the IETF TRILL (Transparent
Interconnection of Lots of Links) protocol to support multi-topology Interconnection of Lots of Links) protocol to support multi-topology
routing of unicast and multi-destination traffic based on IS-IS routing of unicast and multi-destination traffic based on IS-IS
(Intermediate System to Intermediate System) multi-topology specified (Intermediate System to Intermediate System) multi-topology specified
in RFC 5120. This document updates RFC 6325 and RFC 7177. in RFC 5120.
Status of This Memo Status of This Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Distribution of this document is unlimited. Comments should be sent Distribution of this document is unlimited. Comments should be sent
to the TRILL working group mailing list. to the TRILL working group mailing list.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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Shadow Directories can be accessed at Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
INTERNET-DRAFT TRILL: Multi-Topology INTERNET-DRAFT TRILL: Multi-Topology
Table of Contents Table of Contents
1. Introduction............................................3 1. Introduction............................................3
1.1 Terminology............................................4 1.1 Terminology............................................4
2. Topologies..............................................6 2. Topologies..............................................5
2.1 Special Topology Zero..................................6 2.1 Special Topology Zero..................................5
2.2 Links and Multi-Topology...............................6 2.2 Links and Multi-Topology...............................5
2.3 TRILL Switches and Multi-Topology......................6 2.3 TRILL Switches and Multi-Topology......................5
2.4 TRILL Data Packets and Multi-Topology..................7 2.4 TRILL Data Packets and Multi-Topology..................6
2.4.1 Explicit Topology Labeling Support...................7 2.4.1 Explicit Topology Labeling Support...................6
2.4.2 The Explicit Topology Label..........................8 2.4.2 The Explicit Topology Label..........................7
2.4.3 TRILL Use of the MT Label............................9 2.4.3 TRILL Use of the MT Label............................8
3. TRILL Multi-Topology Adjacency and Routing.............11
3.1 Adjacency (Updates to RFC 7177).......................11
3.2 TRILL Switch Nicknames................................11
3.3 TRILL Unicast Routing.................................12
3.4 TRILL Multi-Destination Routing.......................12
3.4.1 Distribution Trees..................................12
3.4.2 Multi-Access Links..................................14
4. Mixed Links............................................15 3. TRILL Multi-Topology Adjacency and Routing.............10
3.1 Adjacency.............................................10
3.2 TRILL Switch Nicknames................................10
3.3 TRILL Unicast Routing.................................11
3.4 TRILL Multi-Destination Routing.......................11
3.4.1 Distribution Trees..................................11
3.4.2 Multi-Access Links..................................13
5. Other Multi-Topology Considerations....................16 4. Mixed Links............................................14
5.1 Address Learning......................................16
5.1.1 Data Plane Learning.................................16
5.1.2 Multi-Topology ESADI................................16
5.2 Legacy Stubs..........................................16
5.3 RBridge Channel Messages..............................16
5.4 Implementations Considerations........................17
6. Allocation Considerations..............................18 5. Other Multi-Topology Considerations....................15
6.1 IEEE Registration Authority Considerations............18 5.1 Address Learning......................................15
6.2 IANA Considerations...................................18 5.1.1 Data Plane Learning.................................15
5.1.2 Multi-Topology ESADI................................15
5.2 Legacy Stubs..........................................15
5.3 RBridge Channel Messages..............................15
5.4 Implementations Considerations........................16
7. Security Considerations................................19 6. Allocation Considerations..............................17
6.1 IEEE Registration Authority Considerations............17
6.2 IANA Considerations...................................17
Normative References......................................20 7. Security Considerations................................18
Informative References....................................21
Acknowledgements..........................................22 Normative References......................................19
Informative References....................................20
Appendix A: Differences from RFC 5120.....................23 Acknowledgements..........................................21
Appendix A: Differences from RFC 5120.....................21
Authors' Addresses........................................24 Authors' Addresses........................................22
INTERNET-DRAFT TRILL: Multi-Topology INTERNET-DRAFT TRILL: Multi-Topology
1. Introduction 1. Introduction
This document specifies extensions to the IETF TRILL (Transparent This document specifies extensions to the IETF TRILL (Transparent
Interconnection of Lots of Links) protocol [RFC6325] [RFC7177] Interconnection of Lots of Links) protocol [RFC6325] [RFC7177]
[RFC7780] to support multi-topology routing for both unicast and [RFC7780] to support multi-topology routing for both unicast and
multi-destination traffic based on IS-IS (Intermediate System to multi-destination traffic based on IS-IS (Intermediate System to
Intermediate System, [IS-IS]) multi-topology [RFC5120]. Intermediate System, [IS-IS]) multi-topology [RFC5120].
Implementation and use of multi-topology are optional and use Implementation and use of multi-topology are optional and use
requires configuration. It is anticipated that not all TRILL campuses requires configuration. It is anticipated that not all TRILL
will need or use multi-topology. campuses will need or use multi-topology.
This document updates [RFC7177] as specified in Section 3.1. This
document updates numerous aspects of [RFC6325] including changing
routing (Sections 3.3 and 3.4), address learning (Section 5.1), and
distribution tree construction (Section 3.4), to take multi-topology
into account.
Multi-topology creates different topologies or subsets from a single Multi-topology creates different topologies or subsets from a single
physical TRILL campus topology. This is different from Data Labels physical TRILL campus topology. This is different from Data Labels
(VLANs and Fine Grained Labels [RFC7172]). Data Labels specify (VLANs and Fine Grained Labels [RFC7172]). Data Labels specify
communities of end stations and can be viewed as creating virtual communities of end stations and can be viewed as creating virtual
topologies of end station connectivity. However, in a single topology topologies of end station connectivity. However, in a single topology
TRILL campus, TRILL Data packets can use any part of the physical TRILL campus, TRILL Data packets can use any part of the physical
topology of TRILL switches and links between TRILL switches, topology of TRILL switches and links between TRILL switches,
regardless of the Data Label of that packet's payload. In a multi- regardless of the Data Label of that packet's payload. In a multi-
topology TRILL campus, TRILL data packets in a topology are topology TRILL campus, TRILL data packets in a topology are
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multicast or IPv6 islands, routing a class of traffic so that it multicast or IPv6 islands, routing a class of traffic so that it
avoids certain TRILL switches that lack some characteristic needed by avoids certain TRILL switches that lack some characteristic needed by
that traffic, or making a class of traffic avoid certain links due to that traffic, or making a class of traffic avoid certain links due to
security, reliability, or other concerns. security, reliability, or other concerns.
It is possible for a particular topology to not be fully connected, It is possible for a particular topology to not be fully connected,
either intentionally or due to node or link failures or incorrect either intentionally or due to node or link failures or incorrect
configuration. This results in two or more islands of that topology configuration. This results in two or more islands of that topology
that cannot communicate. In such a case, end station connected in that cannot communicate. In such a case, end station connected in
that topology to different islands will be unable to communicate with that topology to different islands will be unable to communicate with
INTERNET-DRAFT TRILL: Multi-Topology
each other. each other.
Multi-topology TRILL supports regions of topology-ignorant TRILL Multi-topology TRILL supports regions of topology-ignorant TRILL
switches as part of a multi-topology campus; however, such regions switches as part of a multi-topology campus; however, such regions
can only ingress to, egress from, or transit TRILL Data packets in can only ingress to, egress from, or transit TRILL Data packets in
the special base topology zero. the special base topology zero.
INTERNET-DRAFT TRILL: Multi-Topology
1.1 Terminology 1.1 Terminology
The terminology and acronyms of [RFC6325] are used in this document. The terminology and acronyms of [RFC6325] are used in this document.
Some of these are listed below for convenience along with some Some of these are listed below for convenience along with some
additional terms. additional terms.
campus - The name for a TRILL network, like "bridged LAN" is a campus - The name for a TRILL network, like "bridged LAN" is a
name for a bridged network. It does not have any academic name for a bridged network. It does not have any academic
implication. implication.
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TRILL - Transparent Interconnection of Lots of Links or Tunneled TRILL - Transparent Interconnection of Lots of Links or Tunneled
Routing in the Link Layer [RFC6325]. Routing in the Link Layer [RFC6325].
TRILL Switch - A device implementing the TRILL protocol. TRILL TRILL Switch - A device implementing the TRILL protocol. TRILL
switches are [IS-IS] Intermediate Systems (routers). switches are [IS-IS] Intermediate Systems (routers).
VL - VLAN Labeling or VLAN Labeled or VLAN Label [RFC7172]. By VL - VLAN Labeling or VLAN Labeled or VLAN Label [RFC7172]. By
implication, a "VL RBridge" or "VL TRILL switch" does not implication, a "VL RBridge" or "VL TRILL switch" does not
support FGL or MT. support FGL or MT.
INTERNET-DRAFT TRILL: Multi-Topology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
INTERNET-DRAFT TRILL: Multi-Topology INTERNET-DRAFT TRILL: Multi-Topology
2. Topologies 2. Topologies
In TRILL multi-topology, a topology is a subset of the TRILL switches In TRILL multi-topology, a topology is a subset of the TRILL switches
and of the links between TRILL switches in the TRILL campus. TRILL and of the links between TRILL switches in the TRILL campus. TRILL
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version zero. version zero.
R - A 2-bit reserved field that MUST be sent as zero and ignored R - A 2-bit reserved field that MUST be sent as zero and ignored
on receipt. on receipt.
MT-ID - The 12-bit topology using the topology number space of the MT-ID - The 12-bit topology using the topology number space of the
MT TLV [RFC5120]. MT TLV [RFC5120].
2.4.3 TRILL Use of the MT Label 2.4.3 TRILL Use of the MT Label
With the addition of the MT label, the four standardized content With the addition of the version zero MT label, the four standardized
varieties for the TRILL Data packet data labeling area (the area content varieties for the TRILL Data packet data labeling area (the
after the Inner.MacSA (or Flag Word if the Flag Word is present area after the Inner.MacSA (or Flag Word if the Flag Word is present
[RFC7780]) and before the payload) are as show below. {PRI, D} is a [RFC7780]) and before the payload) are as show below. TRILL Data
3-bit priority and a drop eligibility indicator bit [RFC7780]. All packets received with any other data labeling are discarded. {PRI,
MT TRILL switches MUST support FGL, in the sense of being FGL safe D} is a 3-bit priority and a drop eligibility indicator bit
[RFC7172], and thus MUST support all four data labeling area contents [RFC7780].
shown below.
All MT TRILL switches MUST support FGL, in the sense of being FGL
safe [RFC7172], and thus MUST support all four data labeling area
contents shown below. (This requirement is imposed, rather than
having FGL support and MT support be independent, to reduce the
number of variations in RBridges and simplify testing.)
1. C-VLAN [RFC6325] 1. C-VLAN [RFC6325]
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-VLAN = 0x8100 | PRI |D| VLAN ID | | C-VLAN = 0x8100 | PRI |D| VLAN ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2. FGL [RFC7172] 2. FGL [RFC7172]
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FGL = 0x893B | PRI |D| FGL High Part | | FGL = 0x893B | PRI |D| FGL High Part |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FGL = 0x893B | PRI |D| FGL Low Part | | FGL = 0x893B | PRI |D| FGL Low Part |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
INTERNET-DRAFT TRILL: Multi-Topology
3. MT C-VLAN [this document] 3. MT C-VLAN [this document]
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MT Ethertype = TBD | 0 | R | MT-ID | | MT Ethertype = TBD | 0 | R | MT-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| C-VLAN = 0x8100 | PRI |D| VLAN ID | | C-VLAN = 0x8100 | PRI |D| VLAN ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
INTERNET-DRAFT TRILL: Multi-Topology
4. MT FGL [this document] [RFC7172] 4. MT FGL [this document] [RFC7172]
1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 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 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MT Ethertype = TBD | 0 | R | MT-ID | | MT Ethertype = TBD | 0 | R | MT-ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FGL = 0x893B | PRI |D| FGL High Part | | FGL = 0x893B | PRI |D| FGL High Part |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| FGL = 0x893B | PRI |D| FGL Low Part | | FGL = 0x893B | PRI |D| FGL Low Part |
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Inclusion or use of S-VLAN or further stacked tags are beyond the Inclusion or use of S-VLAN or further stacked tags are beyond the
scope of this document but, as stated in [RFC6325], are obvious scope of this document but, as stated in [RFC6325], are obvious
extensions. extensions.
INTERNET-DRAFT TRILL: Multi-Topology INTERNET-DRAFT TRILL: Multi-Topology
3. TRILL Multi-Topology Adjacency and Routing 3. TRILL Multi-Topology Adjacency and Routing
Routing calculations in IS-IS are based on adjacency. Section 3.1 Routing calculations in IS-IS are based on adjacency. Section 3.1
specifies multi-topology updates to the TRILL adjacency specification specifies multi-topology TRILL adjacency. Section 3.2 describes the
[RFC7177]. Section 3.2 describes the handling of nicknames. handling of nicknames. Sections 3.3 and 3.4 specify how unicast and
Sections 3.3 and 3.4 specify how unicast and multi-destination TRILL multi-destination TRILL multi-topology routing differ from the TRILL
multi-topology routing differ from the TRILL base protocol routing. base protocol routing.
3.1 Adjacency (Updates to RFC 7177) 3.1 Adjacency
There is no change in the determination or announcement of adjacency There is no change in the determination or announcement of adjacency
for topology zero which is as specified in [RFC7177]. When a for topology zero which is as specified in [RFC7177]. When a
topology zero adjacency reaches the Report state as specified in topology zero adjacency reaches the Report state as specified in
[RFC7177], the adjacency is announced in core LSPs using the Extended [RFC7177], the adjacency is announced in core LSPs using the Extended
Intermediate System Reachability TLV (#22). This will be compatible Intermediate System Reachability TLV (#22). This will be compatible
with any legacy topology-ignorant RBridges that might not support E- with any legacy topology-ignorant RBridges that might not support E-
L1FS FS-LSPs [RFC7780]. L1FS FS-LSPs [RFC7780].
Adjacency is announced for non-zero topologies in LSPs using the MT Adjacency is announced for non-zero topologies in LSPs using the MT
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consists of disjoint islands, each distribution tree consists of disjoint islands, each distribution tree
construction for topology T is local to one such island. construction for topology T is local to one such island.
o Only the Nickname sub-TLV, Trees sub-TLV, Tree Identifiers sub- o Only the Nickname sub-TLV, Trees sub-TLV, Tree Identifiers sub-
TLV, and Trees Used sub-TLV occurring in an MT Router TLV, and Trees Used sub-TLV occurring in an MT Router
Capabilities TLV (#144) specifying topology T are used in Capabilities TLV (#144) specifying topology T are used in
determining the tree root(s), if any, for a connected area of determining the tree root(s), if any, for a connected area of
non-zero topology T. non-zero topology T.
+ There may be non-zero topologies with no multi-destination + There may be non-zero topologies with no multi-destination
traffic or, as descried in [RFC5120], even topologies with traffic or, as described in [RFC5120], even topologies with
no traffic at all. For example, if only known destination no traffic at all. For example, if only known destination
unicast IPv6 TRILL Data packets were in topology T and all unicast IPv6 TRILL Data packets were in topology T and all
multi-destination IPv6 TRILL Data packets were in some other multi-destination IPv6 TRILL Data packets were in some other
topology, there would be no need for a distribution tree for topology, there would be no need for a distribution tree for
topology T. For this reasons, a Number of Trees to Compute topology T. For this reason, a Number of Trees to Compute
of zero in the Trees sub-TLV for the TRILL switch holding of zero in the Trees sub-TLV for the TRILL switch holding
the highest priority to be a tree root for a non-zero the highest priority to be a tree root for a non-zero
topology T is honored and causes no distribution trees to be topology T is honored and causes no distribution trees to be
calculated for non-zero topology T. This is different from calculated for non-zero topology T. This is different from
the base topology zero where, as specified in [RFC6325], a the base topology zero where, as specified in [RFC6325], a
zero Number of Trees to Compute causes one tree to be zero Number of Trees to Compute causes one tree to be
computed. computed.
o Nicknames are allocated as described in Section 3.2. If a o Nicknames are allocated as described in Section 3.2. If a
TRILL switch advertising that it provides topology T service TRILL switch advertising that it provides topology T service
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INTERNET-DRAFT TRILL: Multi-Topology INTERNET-DRAFT TRILL: Multi-Topology
Acknowledgements Acknowledgements
The comments and contributions of the following are gratefully The comments and contributions of the following are gratefully
acknowledged: acknowledged:
Vishwas Manral and Martin Vigoureux Vishwas Manral and Martin Vigoureux
The document was prepared in raw nroff. All macros used were defined
within the source file.
INTERNET-DRAFT TRILL: Multi-Topology
Appendix A: Differences from RFC 5120 Appendix A: Differences from RFC 5120
TRILL multi-topology, as specified in this document, differs from RFC TRILL multi-topology, as specified in this document, differs from RFC
5120 as follows: 5120 as follows:
1. [RFC5120] provides for unicast multi-topology. This document 1. [RFC5120] provides for unicast multi-topology. This document
extends that to cover multi-destination TRILL data distribution extends that to cover multi-destination TRILL data distribution
(see Section 3.4). (see Section 3.4).
2. [RFC5120] assumes the topology of data packets is always 2. [RFC5120] assumes the topology of data packets is always
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