2011年10月6日星期四

Let's obtain slightly train with this. what's the webwork portion of the adclothe23.14.189.200

Passing the CompTIA Network+ certification exam and happening to transform a subnetting professionalis mastering the fundamentals of IP addressing, and that suggests understanding the diffehireclasses, their default masks, and whon these masks mean. Let抯 begin!

a part of every IP adclotheindicates the webwork the host is a chapter of, and the opposite part identifies that expresshost. you wish to have so that you tin take a look by an IP adclotheand diagram outthe webwork and host portions, and also you do this by determining the category of the address.

Many books catalogue merely three network classes, whatever tlisted here are 5. because you absence ton't apportion an adclothefrom the los angelesst two lessonsto a number, you better know whon they're ugg roseberry!

eleganceA networks have a beginning octet of one - 126.

eleganceB networks have a beginning octet of one28-191.

eleganceC networks have a beginning octet of one92 - 223.

realizea host missing? 127 is the reserved first octet for loopback addresses, this type ofs the 127.0.0.1 adclotheassigned to a microprocessor.

eleganceD networks are reserved for multicasting. eleganceD addresses startwith an octet within the 224 - 23ninerange.

eleganceE networks are reserved as "tentative use", and the basicoctet of those addresses is two40 - 255. Those addresses are kept by the netEngineering Task Force (IETF). Neither eleganceD neither eleganceE networks absence to be assigned to host devices. For exam and real-globalpurposes, entire of the adclothediversity224.0.0.0 - 255.255.255.25fiveare unacceptable for delegation to network hosts, for is whichever adclothebeginning with 127.

Now, what does all this need to do with identifying the webwork and host portions of an address? lessonsA, B, and C all have diffehiredefault network masks, and that it isthat mask that tells you which of them a part of an adclotheis the webwork portion and which part is the host portion.

eleganceA's default mask is two55.0.0.0, alternatively /8

eleganceB's default mask is two55.255.0.0, or /16

eleganceC's default mask is two55.255.255.0, or /24.

despite the fact that you justwere alin a positionconversant within the se default masks uggs liberty boots 5509, you will be wondering what that "/8" affair is. that is in a another usage to exacta network mask. it isknown asprefix notation, and that it ismuch simpler than it sounds. The digit back the slash is simplythe alternative of successive ones initially of the mask once It isexpressed in binary.

255.0.0.0 in binary is 11111111 00000000 00000000 00000000.

255.255.0.0 in binary is 11111111 11111111 00000000 00000000.

255.255.255.0 in binary is 11111111 11111111 11111111 00000000.

when you blot all of the worths in an octet set to 1 ugg roseberry, the value of the octet is two55. ought you spot an IP adclothewith an octet installperthan 255, it isinvalid. ("256.1.1.1" literally cannot occur, so it is an invalid address.)

Prefix exegesis is the maximum well liked access of expressing subinternetmasks. A mask of /8 is affirmed "slash eight", that is distant better than mentioning "two-fifty-five naught naught zero". It also has fewer mathematics to type, which I still believe is the tangible cause we use it! you might no watch prelude notation for your Network+ exam, merely for it抯 so commonly utilized in network documentation, you wish to need to are aware of it.

Now, almost those web and host parts.....

the category A network mask 255.0.0.0 method the basicoctet of the adclotheis the webwork portion, and the general three octets are the host portion.

the category B network mask 255.255.0.0 means the basictwo octets of the adclotheare the webwork portion, and the general 2 octets are the host portion.

the category C network mask 255.255.255.0 means the basicthree octets of the adclotheare the webwork portion, and the general octet is the host portion.

Identifying the webwork or host part of a given IP adclotheis a two-step process:

1. figure outthe adclotheeleganceby examining the basicoctet

2. Use the webwork mask to figure out the webwork and host portions

Let's get slightly train with this. what's the webwork part of the adclothe23.14.189.200?

1. the basicoctet falls into the category a variety

2. the webwork mask for sophistication A is two55.0.0.0, averaging thon the basicoctet of the adclotheis the webwork portion and the rest three octets are the host portion

That's really all of there's to it. the basicoctet, "23", is the webwork portion. the rest octets ugg highkoo boots, "14.189.200", comprise the host portion.

It抯 simplythat straightforward to spot the webwork and host portions of an IP address. But what happens once we flee out of IP addresses for our hosts? locateout in my next CompTIA Network Plus exam tutorial!






CompTIA Network+ Certification Exam Tutorial: The Five IP AdclotheClasses

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