17 Fabric Path Overview v2

8/2/2019 17 Fabric Path Overview v2

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Cisco FabricPath OverviewCisco FabricPath Overview


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La er 2 for Data Centers

FabricPath Simple, Efficient, Scalable Layer 2

2009 Cisco Systems, Inc. Al l r ights reserved. Cisco ConfidentialPresentation_ID 2


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Layer 2 for Data CentersLayer 2 for Data Centers



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La er 2 is still re uired b some data center

applications If Layer 2 VLANs exist everywhere:

Server mobility does not require interaction betweenNetwork/Server teams

Layer 2 is Layer 3 agnostic



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Branches of trees nevern erconnec no oop

11 Ph sical Links 5 Lo ical Links

S2

S1 S3

e pann ng ree rotoco s typ ca y use tobuild this tree

Tree to olo im lies:

Wasted bandwidth -> over-subscription exacerbated

Sub-optimal paths


onserva ve convergence -> a ure ca as rop c


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Simple, Efficient, Scalable Layer 2



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Introducing Cisco FabricPath- -

FabricPath brings Layer 3 routing benefits toFabricPath brings Layer 3 routing benefits to

SwitchingSwitching RoutingRouting

asy on gura on

Plug & Play

Provisioning Flexibility

u -pa ng

Fast Convergence

Highly Scalable

FabricPathFabricPath


ScalableBandwidth

u o- scoverySimple Operation

ex e or oaMobility

High-availability


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IS-IS assigns addresses to all FabricPath switches automatically

Plug-N-Play L2 IS-IS is used to manage forwarding topology

Compute shortest, pair-wise paths Support equal-cost paths between any FabricPath switch pairs

S1 S2 S3 S4

FabricPathRouting Table

FabricPathRouting Table

L1

L2L3

Switch IF

S1 L1

S2 L2

S3 L3

S11 S12 S42

L2 FabricL2 FabricL4S12 L1, L2, L3, L4

S42 L1, L2, L3, L4



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Forwarding decision based on FabricPath Routing Table

FabricPath header is imposed by ingress switch

S1 S2 S3 S4

Only switch addresses are used to make routing decisions No MAC learning required inside the L2 Fabric

FabricPath

Routing Table

FabricPath

Routing Table S11 S42S11 S42A BA B

S11 S12 S42FabricPathFabricPathSwitch IF

S42 L1, L2, L3, L4

Classical EthernetMac Address TableClassical EthernetMac Address Table

A BMAC IF

A 1/1

1/1ClassicalClassical

EthernetEthernet


B S42


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No L2 IS-IS confi uration re uired

Single control protocol for unicast, multicast, vlan pruning

N7K(config)# feature-set fabricpath

N7K(config)# fabricpath switch-id

N7K(config)# feature-set fabricpath

N7K(config)# fabricpath switch-id

N7K(config) interface ethernet

N7K(config-if)# switchport mode fabricpath

N7K(config) interface ethernet

N7K(config-if)# switchport mode fabricpath

L2 FabricL2 Fabric1/1

FabricPath Port

CE Port



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Shortest path, Multi-Pathing, High-availability

Shortest path for low latency

S1 S2 S3 S4

Up to 256 links active between any 2 nodes High availability with N+1 path redundancy

L1

L2

S11 S12 S42

L3

L4

Switch IF

S42 L1, L2, L3, L4


A B


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Safe Data Plane, Conversational learning

TTL and RFP check the data plane protect against loopsL2 can be extended in the data center (while STP is segmented)

Conversational learning allows scaling mac address tables atthe edge

FabricPathFabricPath

S11 S42

(no mac address learning in the Fabric)(no mac address learning in the Fabric)

S22

Classical EthernetClassical Ethernet

A B

Classical EthernetClassical Ethernet Classical EthernetClassical Ethernet

Mac Address Table

Mac Address Table

MAC IF

A 1/1

ClassicalClassicalEthernetEthernet

Mac Address Table

Mac Address Table

Mac Address Table

Mac Address Table

MAC IF

MAC IF

A S11


B S42 B 1/1


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Layer 3 NetworkLayer 3 Network

vPC+ helps integrating CE devices

Allows inserting non-FabricPath capable devices in

FHRPFHRP

ActiveActive L3 Routing

L2 FabricL2 FabricL2 FabricL2 Fabric

the network:

With Active/Active redundancy

Without rel in on STP

FHRP

FabricPath

(port channels)

Provides active/active FHRP Classical

Ethernet

Non-FabricPath


capable devices


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FabricPath Use CasesFabricPath Use Cases



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Workload Flexibility with FabricPath

Single domain Responsive

Pooled compute resources

Increased agility

Virtualized Applications movewithin minutes vs. days

Ca ex and O ex savin sworkload mobility Maximize resource utilization,

simplify IT operations

-

Web ServersWeb Servers

e wor a r ce wor a r c


Silo 1Silo 1 Silo 2Silo 2 Silo 3Silo 3

App ServersApp Servers

New AppsNew Apps


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Use Case: High Performance Compute

16 Chassis 8,192 10GE portsSpine Switch

16-way ECMP

16-port Etherchannel

32 Chassis256 10GE FabricPath Ports

160 Tbps System Bandwidth

Open I/O Slots forconnectivity

Edge Switch

HPC Requirements

HPC Clusters require high-

FabricPath Benefits for HPC

FabricPath enables building a high-

density of compute nodes

Minimal over-subscription

density fat-tree network

Fully non-blocking with FabricPathECMP & port-channels


Minimize switch hops to reduce

server to server latencies


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Scaling Bandwidth with FabricPath

,

16X improvement in bandwidth performance

From 74 managed devices to 12 devices 2X+ increase in network availability

Simplified IT operations

Traditional Spanning Tree Based Network FabricPath Based Network

FullyN

Blocked Links

:1o

n-Blocking

Network FabricNetwork Fabric

subscription

1

:1

2:1

4Pods


2, 048 Servers

8 Access Switches64 Access Switches

2, 048 Servers

Ove


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IXP Requirements

Layer 2 Peering enables multiple

providers to peer their internetrouters with one another

Provider A Provider B

10GE non-blocking fabric

Scale to thousands of ports

FabricPath Benefits for IXP

Transparent Layer 2 fabric

Bandwidth not limited by chassis /port-channel limitations

Provider C Provider D


Simple to manage, economical tobuild


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FabricPath is sim le, kee s the attractive as ects

of Layer 2Transparent to L3 protocols,

FabricPath is efficient

High bi-sectional bandwidth (ECMP)p ma pa e ween any wo no es

FabricPath is scalableCan extend a bridged domain without extending the risks generally

associated to Layer 2 (frame routing, TTL, RPFC)



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Documents

17 Fabric Path Overview v2