subnet woes.
hexem
Member Posts: 177
in CCNA & CCENT
Ok so iv'e checked out the easy subnetting guide on here, seem's pretty easy to follow but when it come's to class a/b addresses, i get confused slightly.
take this for example.
105.254.219.251/15
Ok so following the guide,
16 - 15 = 2 ^ 1 = 2 (block size?)
Addresses like this confuse me..
take this for example.
105.254.219.251/15
Ok so following the guide,
16 - 15 = 2 ^ 1 = 2 (block size?)
Addresses like this confuse me..
ICND1 - Passed 25/01/10
ICND2 - Passed 9/03/10
Studying CCNA:S
ICND2 - Passed 9/03/10
Studying CCNA:S
Comments
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miller811 Member Posts: 897Ok so iv'e checked out the easy subnetting guide on here, seem's pretty easy to follow but when it come's to class a/b addresses, i get confused slightly.
take this for example.
105.254.219.251/15
Ok so following the guide,
16 - 15 = 2 ^ 1 = 2 (block size?)
Addresses like this confuse me..
always use the following
There are 3 main classes of IP address that we are concerned with.
Class A Range 0 - 127 in the first octet (0 and 127 are reserved)
Class B Range 128 - 191 in the first octet
Class C Range 192 - 223 in the first octet
Below shows you how, for each class, the address is split in terms of network (N) and host (H) portions.
NNNNNNNN . HHHHHHHH . HHHHHHHH . HHHHHHHH Class A
NNNNNNNN . NNNNNNNN . HHHHHHHH . HHHHHHHH Class B
NNNNNNNN . NNNNNNNN . NNNNNNNN . HHHHHHHH Class C
so it is a class A address
105.254.219.251/15
7 bits are being borrowed so it is a 2 bit range, as you stated
subnet 105.254.0.0
first host 105.254.0.1
last host 105.255.255.254
broadcast 105.255.255.255
17 bits are used for the host addresses = 131072 (-2) hosts
practice here
IP Subnet PracticeI don't claim to be an expert, but I sure would like to become one someday.
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