IP address question

sid160sid160 Member Posts: 5 ■□□□□□□□□□
Hi all,
Got a question for you...
How are the first octets of class A, B and C IP addresses represented in binary?
Class A: 01xxxxxx?
Class B: ........?
Class C: ......?

Thanks for you help.


  • WebmasterWebmaster Admin Posts: 10,292 Admin
    Take a look at icon_arrow.gifwww.techexams.net/technotes/networkplus/tcpipsuite.shtml

    It will show you the first octets as well as how to convert from decimal to binary. You must be able to do this from the top of your head for the CCNA exam... give it a shot and give us the answer.. icon_wink.gif
  • sid160sid160 Member Posts: 5 ■□□□□□□□□□
    Got it....

    Class A: 0xxxxxxx
    Class B: 10xxxxxx
    Class C: 110xxxxx
  • WebmasterWebmaster Admin Posts: 10,292 Admin
    Actually, the answers are:

    The first octet of a
    Class A IP address, can be 1 to 126
    Class B IP address, can be 128 to 191
    Class C IP address, can be 192 to 223

    Listing the binary equivalents of these would result in a long long post ;)

    The first octet of a
    Class A subnet mask is 255, as in
    Class B subnet mask is 255, second octet is also 255, as in
    Class C subnet mask is 255, second and third octet are also 255, as in

    In binary a class A subnet mask is: 11111111.00000000.00000000.00000000

    a class B subnet mask is:

    and class C:
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