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Table Of Contents
VMware Server User’s Guide
248 VMware, Inc.
IfyouwantalluserstobeabletosetthevirtualnetworkAdapter(/dev/vmnet0inour
example)topromiscuousmode,runthefollowingcommandastherootuseronthe
host:
chmod a+rw /dev/vmnet0
Understanding NAT
Networkaddresstranslation,orNAT,providesasimplewayforvirtualmachinesto
usemostclientapplicationsoveralmostanytypeofnetworkconnectionavailableto
thehost.TheonlyrequirementforNATisthatthenetworkconnectionmustsupport
TCP/IP.
NATisusefulwhenyouhavealimitedsupplyof
IPaddressesorareconnectedtothe
networkthroughanonEthernetnetworkadapter.NATworksbytranslatingaddresses
ofvirtualmachinesinaprivateVMnetnetworktothatofthehostmachine.Whena
virtualmachinesendsarequesttoaccessanetworkresource,itappearstothenetwork
resourceasiftherequestcamefromthehostmachine.
NATusesthehost’sownnetworkresourcestoconnecttotheexternalnetwork.Thus,
anyTCP/IPnetworkresourcetowhichthehosthasaccessshouldbeavailablethrough
theNATconnection.
ThechiefadvantageofNATisthatitprovidesa
transparent,easytoconfigurewayfor
virtualmachinestogainaccesstonetworkresources.
ThefollowingsectionsprovidemoreinformationaboutNAT.
Using NAT
TheNATdeviceisconnectedtotheVMnet8virtualswitch.Virtualmachinesconnected
totheNATnetworkalsousetheVMnet8virtualswitch.
TheNATdevicewaitsforpacketscomingfromvirtualmachinesontheVMnet8virtual
network.Whenapacketarrives,theNATdevicetranslatestheaddressofthevirtual
machinetothatofthehostbeforeforwardingthepackettothe externalnetwork.When
dataarrivesfromtheexternalnetworkforthevirtualmachineontheprivatenetwork,
theNATdevicereceivesthedata,replacesthenetworkaddresswiththatofthevirtual
machineandforwardsthedatatothe
virtualmachineonthevirtualnetwork.This
translationoccursautomaticallyandrequiresminimalconfigurationontheguestand
thehost.