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 A X 2,2,11 2,3,3 2,2,4 2,1,14 2,1,5 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 ProtocolOSPFIS-IS AlgorithmDijkstra Classless(VLSM)Support NetworkOriginal for IPOriginal for CLNS AddressIPNSAP TopologyPoint-to-point Point-to-multicast Broadcast Nonbroadcast Point-to-point Broadcast

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 8 Egress RBridge Nickname Ingress RBridges Nickname VRMOPLngHop TRILL Ethertype

RBridging 9 BR4 BR3 BR2 BR1 BR5 BR6 BR7 LAN

Comparison Bridges with STP 10 B1 B2B3 :end-node

Comparison Cont. RBridges with TRILL 11 B1 B2B3

Conclusion 12 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 13

Network Devices 14 DeviceRepeaterHubBridgeSwitch OSI LayerLayer 1 Layer 2 Number of port 2>22 Back