Zte ZXR10 8900 Series - Page 72

ZXR108900SeriesUserManual(BasicCongurationVolume)
Class
Prex
Characteristic
Bit
Network
Bit
HostBit
Range
Class
D
1110
Multicastaddress
224.0.0.0to
239.255.255.255
ClassE
1111
Reserved
240.0.0.0to
255.255.255.255
SomeaddressesofClassA,BandCarereservedforprivatenet-
works.Itisrecommendedthattheinternalnetworkshoulduse
theprivatenetworkaddress.Theyare:
�ClassA:10.0.0.0to10.255.255.255
�ClassB:172.16.0.0to172.31.255.255
�ClassC:192.168.0.0to192.168.255.255
Thisaddressclassicationmethodistofacilitateroutingprotocol
designing.Fromthismethoditcanbeknownthenetworktypejust
bytheprexcharacteristicbitoftheIPaddress.Thismethod,
however ,cannotmakethebestoftheaddressspace.Withthe
dramaticexpansionofInternet,problemofaddressshortagebe-
comesincreasinglyserious.
Network,Subnet
andHostBit
TomakemostofIPaddresses,networkcanbedividedintomultiple
subnets.Borrowsomebitsfromthehighestbitofthehostbit
asthesubnetbit.Remainingpartofthehostbitstillservesas
thehostbit.IPaddressiscomposedofthreeparts:networkbit,
subnetbitandhostbit.
Networkbitandsubnetbitidentifyanetworkuniquely.Subnet
maskisusedtodecidewhichpartsofIPaddressarethenetwork
bits,subnetbitandhostbit.Thepartwiththesubnetmaskbeing
1correspondstothenetworkbitandsubnetbitoftheIPaddress.
Partwiththesubnetmaskbeing0correspondstothehostbit.
DivisionofthesubnetgreatlyimprovestheutilizationoftheIP
address,andalleviatestheproblemofIPaddressshortage.
SomeconventionsforIPaddresses:
�0.0.0.0isusedwhenthehostwithoutanIPaddressisstarted.
AddressisobtainedthroughRARP,BOOTPandDHCP .Thisad-
dressisalsousedasadefaultrouteintheroutingtable.
�255.255.255.255isusedforthedestinationaddressofbroad-
castandcannotbeusedasasourceaddress.
�127.X.X.Xiscalledloop-backaddress.WhentheactualIPad-
dressofthehostisnotknown,thisaddressisusedtorepresent
“thishost”.
�Addresswithonlythehostbitbeing0indicatesthenetworkit-
self.Addresswiththehostbitbeing1isthebroadcastaddress
ofthenetwork.
�NetworkpartorthehostpartofavalidhostIPaddresscannot
beall0or1.
60CondentialandProprietaryInformationofZTECORPORATION