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Table Of Contents
VMware, Inc. 255
Chapter 11 Configuring a Virtual Network
Thisbehavioriscontrolledbyentriesinsectionsheaded[privilegedUDP]and
[privilegedTCP].Youmighthavetoaddsettingstoormodifysettingsineitheror
bothofthesesections,dependingonthekindofconnectionyouneedtomake.
Youcansettwoparameters,eachofwhichappearsonaseparate
line.
autodetect = <n>
TheautodetectsettingdetermineswhethertheVMwareNATdeviceautomatically
attemptstomapvirtualmachinesourceportsbelow1024toNATsourceportsbelow
1024.Asettingof1meanstrue.Asettingof0meansfalse.OnaWindowshost,the
defaultis1(true).OnaLinux
host,thedefaultis0(false).
port = <n>
Theportsettingspecifiesadestinationport(<n>istheportontheserverthataccepts
theconnectionfromtheclient).Wheneveravirtualmachineconnectstothespecified
portonanyserver,theNATdeviceattemptstomaketheconnectionfromasource
port
below1024.Youcanincludeoneormoreportsettingsinthe[privilegedUDP]or
[privilegedTCP]sectionorinbothsections,asrequiredfortheconnectionsyouneed
tomake.Eachportsettingmustbeenteredonaseparateline.
Considerations for Using NAT
BecauseNATrequiresthateverypacketsentandreceivedfromvirtualmachinesbein
theNATnetwork,thereisanunavoidableperformancepenalty.Ourtestingshowsthat
thepenaltyisminorfordialupandDSLconnections,andperformanceisadequatefor
mostVMwareServ eruses.
NATisnotperfectlytransparent.
Itdoesnotnormallyallowconnectionstobeinitiated
fromoutsidethenetwork,althoughyoucansetupserverconnectionsbymanually
configuringtheNATdevice.ThepracticalresultisthatsomeTCPandUDPprotocols
thatrequireaconnectionbeinitiatedfromtheservermachinesomepeertopeer
applications,forexampledonot workautomatically,andsomemightnotworkatall.
AstandardNATconfigurationprovidesbasiclevelfirewallprotectionbecausethe
NATdevicecaninitiateconnectionsfromtheprivateNATnetwork,butdevicesonthe
externalnetworkcannotnormallyinitiateconnectionstotheprivateNATnetwork.
Using NAT with NetLogon
WhenusingNATnetworkinginavirtualmachinewithaWindowsguestoperating
systemrunningonaWindowshost,youcanuseNetLogontologontoaWindows
domainfromthevirtualmachine.YoucanthenaccessfilesharesknownbytheWINS
serverinthedomain.