Enterasys Matrix DFE-Gold Series User Manual

Enterasys Matrix DFE-Gold Series Configuration Guide 23-1
23
Transparent Web Cache Balancing Configuration
ThischapterdescribestheTransparentWebCacheBalancing(TWCB)commandsandhowtouse
them.
Understanding Transparent Web Cache Balancing (TWCB)
TransparentWebCacheBalancing(TWCB)providesforthestoringoffrequentlyaccessedweb
objectsonacacheoflocalservers.EachHTTPrequestistransparentlyredirectedbytheN‐Series
routertoaconfiguredcacheserver.Whenauserfirstaccessesawebobjectthatobjectisstoredon
acache
server.Eachsubsequentrequestfortheobjectusesthiscachedobject.Webcachingallows
multipleuserstoaccesswebobjectsstoredonlocalcacheserverswithamuchfasterresponsetime
thanaccessingthesameobjectsoveraninternetconnectionorthroughadefaultgateway.Thiscan
alsoresultin
substantialcostsavingsbyreducingtheinternetbandwidthusage.
TheN‐Seriesrouterdoesnotactasacacheforwebobjects;rather,itredirectsHTTPrequeststo
localserversonwhichwebobjectsarecached.Thecacheserversshouldhaveaweb‐basedproxy
cacherunning.TheSquidapplicationis
anexampleofaweb‐basedproxycache.
ImplementingaTWCBconfigurationrequiresuserstoconfigurearoutednetworkwithIP
interfacesthatallowtheN‐Seriesroutertosendrequestsfortheinternettothecorrectweb
cachingdevice.
TherearefiveaspectstoTWCBconfiguration:
• Createtheserverfarms
thatwillcachethewebobjects.Aserverfarmismadeupof1ormore
cacheservers.
•SpecifytheenduserswhoseHTTPrequestswillorwillnotberedirectedtothecacheservers.
Thisstepisoptional.Ifnohostsareconfigured,thefirmwareredirectsallHTTPrequests.
•Specifythe
websitehoststhatwillnottakepartinTWCB.
• Createaweb‐cachethattheserverfarmswillbeassociatedwith.
•ApplythecachingpolicytoanoutboundinterfacetoredirectHTTPtrafficonthatinterfaceto
thecacheservers.
Figure 23‐1providesanexampleofaTWCBconfigurationoverview.The
web‐cacheismadeupof
serverfarmswhichlogicallygrouponeormorecacheservers.Inourexample,Cache1isthename
oftheweb‐cache.Itismadeupoftwoserverfarms:s2Serversands1Servers.Thes1Serverserver
Router: Unless otherwise specified, the commands covered in this chapter can be executed only
when the device is in router mode. For details on how to enable router configuration modes, refer to
Enabling Router Configuration Modes on page 2-103.
Note: An Enterasys Feature Guide document that contains a complete discussion on TWCB
configuration exists at the following Enterasys web site: http://www.enterasys.com/support/
manuals/

Enterasys Matrix DFE-Gold Series Specifications

General

Brand	Enterasys
Model	Matrix DFE-Gold Series
Category	Switch
Language	English