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DistributedOverlay

Virtual

Ethernet

(DOVE)Networks

RenatoRecio

IBMFellow&

SystemNetworking

CTO

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Campus

Access Layer

Aggregation Layer

Core Layer

EarlyEthernetCampusEvolution

Inthebeginning,Ethernetwasusedto

interconnectstations(e.g.dumbterminals),

initiallythroughrepeater&hubtopologies,

eventuallythroughswitchedtopologies.

Ethernetcampusesevolvedintoa

structurednetworktypicallydivided

intoaCore,Service(e.g.firewall),

Aggregationand

Access

Layer.

TrafficpatternismostlyNorthSouth(directedoutsidecampusvs peerpeer).

Toavoidspanningtreeproblems, campus

networks

typically

are

divided

at

access.

WAN

5%

95%

Layer3

Layer2

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Layer2

Layer2

SAN

EthernetintheDataCenter

Thesamestructurednetworktopologies

wereusedinthedatacenter, but

TrafficpatternismostlyEastWest(e.g.ApplicationtoDatabasetier).

Largelayer

2domains

needed

for

clusteringandVirtualMachinemobility.

PartlyduetoEthernetlimitations

(e.g.lack

of

flow

control),

the

data

center

usedadditionalnetworks,suchas

FibreChannelStorageAreaNetworks(SAN)

InfiniBandclusternetworks.

WAN

Data Center

Access Layer

Core Layer

Aggregation Layer

> 75%