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Thread ID: 110591 2010-06-24 05:27:00 Class A B C IP addresses Knuth (15845) Press F1
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1113009 2010-06-24 05:27:00 Can anyone please explain how Class A B C IP addresses are assigned, how it works and the reasons for doing it this way. I have read text book and wikipedia and makes no sense.

Any assitance welcome!
Knuth (15845)
1113010 2010-06-24 05:28:00 . Knuth (15845)
1113011 2010-06-24 06:12:00 See here (www.catb.org) - normally I'd consider this a DYOFH question (ditto for the other threads you started recently) - note that most tech types are fairly good at spotting these.


...I have read text book and wikipedia and makes no sense.Which part of the explanation confuses you? It would help to know where you're getting stuck, otherwise you're likely to just get replies that say more or less the same thing as your textbooks.
Erayd (23)
1113012 2010-06-24 06:18:00 With a Class A network address, the first octet defines the network, and the other three can all be used to define host addresses, therefore each Class A network can contain up to 16,777,214 hosts (24 bits are used for the host portion of the address, and the first and last addresses are always the network address and the broadcast address, respectively, so this is (2^24) - 2 usable host addresses). A Class B address uses the first two octets (16 bits) of the address for the network, and therefore has less hosts per network ((2^16) - 2). Class C uses the first three octets for the network. Any IP address from 0.0.0.0 to 127.255.255.255 is a Class A address, Class B is from 128.0.0.0 to 191.255.255.255 and Class C is from 192.0.0.0 to 223.255.255.255. Addresses above this (Class D and E) are used for multicast (Class D) and reserved (Class E). Class D and E are not generally used.

These days with subnetting, one organisation will not necessarily own all of a Class A or B network. This is referred to as classless addressing.
ryanjames.powell (13554)
1113013 2010-06-24 07:45:00 Thanks that makes it a lot clearer Knuth (15845)
1113014 2010-06-24 09:22:00 Thanks that makes it a lot clearerHmm - if that was really all you needed, I strongly recommend you invest in a new textbook. Most good books will explain things in similar terms to those that ryanjames.powell used; if you found yours unclear on this point then it's likely you'll run into other issues with it later on.

If your current one is a set book for your course then you may be stuck with it, but nothing's stopping you having multiple textbooks - at least you'll have an additional resource to consult.
Erayd (23)
1113015 2010-06-24 09:39:00 Thanks that makes it a lot clearer

Just copy and paste into the homework. That won't make you understand but you might get a A.
Sweep (90)
1113016 2010-06-24 09:42:00 Just copy and paste into the homework. That won't make you understand but you might get a A.Indeed. He'll fail the exam though, so we're still safe :rolleyes:. Erayd (23)
1113017 2010-06-24 11:34:00 ABC, diff amount of host and networks. They start at diff numbers. A 192 is a Class C which is what your router might be at home.

MNC will have Class A - 0.0.0.0 up to not incl 128.0.0.0
4 Octets is in the IP. Class A for example has 1 of network I think and 3 for host.

Then you can do your maths :lol: IP address, subnet mask, first and last, and broadcasting :D
Nomad (952)
1113018 2010-06-24 11:44:00 For maths easiest way is to get a pen and a calculator and do it. Nomad (952)
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