ThenumberofhomeusersandsmallbusinessesthatwanttousetheInternetiseverincreasing.Theshortageofaddressesisbecomingaseriousproblem.Aquicksolutiontothisproblemiscallednetworkaddresstranslation(NAT).NATenablesausertohavealargesetofaddresses(请作答此空)andoneaddress,orasmallsetofaddresses,externally.Thetrafficinsidecanusethelargeset;thetraffic(),thesmallset.ToseparatetheaddressesusedinsidethehomeorbusinessandtheonesusedfortheInternet,theInternetauthoritieshavereservedthreesetsofaddressesas()addresses.AnyorganizationcanuseanaddressoutofthissetwithoutpermissionfromtheInternetauthorities.Everyoneknowsthatthesereservedaddressesareforprivatenetworks.Theyare()insidetheorganization,buttheyarenotuniqueglobally.Norouterwill()apacketthathasoneoftheseaddressesasthedestinationaddress.ThesitemusthaveonlyonesingleconnectiontotheglobalInternetthrougharouterthatrunstheNATsoftware.
A.absolutely B.completely C.internally D.externally正确答案C