Transparent Interconnection of Lots of Links(TRILL)Speaker: Hui-Hsiung Chung

Date:2011/12/28

1

Introduction

Spanning Tree Protocol(STP) A protocol that ensures a loop-free topology for

any bridged Ethernet local area network. Bridge

TRILL A protocol to perform Layer 2 bridging using

Intermediate System to Intermediate System(IS-IS) link state routing.

Routing Bridge(RBridge)

2

STP

3

I think that I shall never see A graph more lovely than a tree.A tree whose crucial property Is loop-free connectivity.A tree which must be sure to span So packets can reach every LAN.First the Root must be selected By ID it is elected.Least cost paths from Root are traced In the tree these paths are placed.A mesh is made by folks like me. Then bridges find a spanning tree.

Radia Perlman

STP Cont.

4

P.S. lowest root bridge id, lowest path cost, lowest sender bridge id

2

3

5

4

67

14

11

10

9

A

X

2,2,11

2,3,3

2,2,4

2,2,4

2,1,14

2,1,5

2,0,2

2,0,2

2,1,6

2,1,7

Introduction

Spanning Tree Protocol(STP) A protocol that ensures a loop-free topology for

any bridged Ethernet local area network. Bridge

TRILL A protocol to perform Layer 2 bridging using

Intermediate System to Intermediate System(IS-IS) link state routing.

Routing Bridge(RBridge)

5

IS-IS

A link state routing protocol Developed by DECnet Phase V

6

Routing Protocol

OSPF IS-IS

Algorithm Dijkstra Dijkstra

Classless(VLSM) Support Support

Network Original for IP Original for CLNS

Address IP NSAP

Topology Point-to-pointPoint-to-multicastBroadcastNonbroadcast

Point-to-pointBroadcast

RBridge

Compatible with existing bridges and routers Like routers, terminate bridges’ spanning

tree Like bridges, glue LANs together a IP subnet Like routers, optimal path, fast convergence Like bridges, plug-and-play Link state protocol among RBridges Like bridges, learn location of end-nodes

from receiving data traffic

7

TRILL

TRILL Header V (Version): 2-bit R (Reserved): 2 –bit M (Multi-destination): 1 bit Op-Lng (Options Length): 5-bit Hop Count: 6-bit Egress RBridge Nickname: 16-bit identifier Ingress RBridge Nickname: 16-bit identifier

8Egress RBridge Nickname

Ingress RBridges Nickname

V R M OPLng HopTRILL Ethertype

RBridging

9

BR4

BR3

BR2

BR1

BR5

BR6

BR7

LAN

Comparison

Bridges with STP

10

B1

B2 B3

:end-node

Comparison Cont.

RBridges with TRILL

11

B1

B2 B3

Conclusion

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I hope that we shall one day see A graph more lovely than a tree.A graph to boost efficiency While still configuration-free.A network where RBridges can Route packets to their target LAN.The paths they find, to our elation, Are least cost paths to destination!With packet hop counts we now see, The network need not be loop-free!RBridges work transparently, Without a common spanning tree.

Ray Perlner

Reference

RFC 5556 RFC 6325 Tutorial on Bridges, Routers, Switches, Oh

My! Bridges and the TRILL protocol

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Network Devices

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Device Repeater Hub Bridge Switch

OSI Layer Layer 1 Layer 1 Layer 2 Layer 2

Number of port

2 >2 2 > 2

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