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Jun 17, 2003, 09:08 AM
#1
Internet Addressing
PSTN = 7 digits (xxx - xxxx)
IP Addressing = 32-bits (4 8-bit quad notation)
Dotted Decimal Notation
255.0.0.0} Decimal
Decimal Quad
Octet
11111111.00000000.00000000.00000000
8-bits 8-bits 8-bits 8-bits
IP Address are actually binary notation.
The version of IP Addressing that is currently in use by most internet users is IP Version 4 (IPv4).
IP version 6 a 128-bit version, is started to replace Ipv4. IP Version 6 is sometimes represented as Ipv6 or IPnG which means IP New Generation.
Base 2 = Binary (0-1)
Base 10 = Decimal (0-9)
Base 16 = Hexadecimal (0-9 & A-F)
Classes of IP Address
Addresses Class Range Reserved Octet Positions
Class A 0-126 xxx.000.000.000
Class B 128-191 xxx.xxx.000.000
Class C 192-233 xxx.xxx.xxx.000
Class D 234-239 Reserved for Multitasking
Class E 240-255 Reserved for Scientific & Future use
The 127 Range is reserved for loop back testing.
Depending on the class of IP Address, the reserved octets will indicate the network portion of the Address & the remaining octet(s) will indicate the host portion. IP Address are made up of 2 portions:
> The Network portion
> The Host Portion
Eg. Class A 121.54.7.19
a b
Class B 130.27.217.3
Key a = Network
b = Host
Contd.
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Jun 17, 2003, 09:15 AM
#2
Re:Internet Addressing
IANA
InterNIC – Network Information Center
Network Solutions
Address Class Network Available Host Available
Class A 127 16,777,214
Class B 16,384 65,534
Class C 2,097,152 254
Understanding Binary
2n Decimal
20 1
21 2
22 4
23 8
24 16
25 32
26 64
27 128
Class A
High Order Bit = 0
Value = 127
128 64 32 16 8 4 2 1
0 1 1 1 1 1 1 1
64 + 32 + 16 + 8 + 4 + 2 + 1 = 127
Class B
High Order Bit = 10
Value = 191
128 64 32 16 8 4 2 1
1 0 1 1 1 1 1 1
128 + 32 + 16 + 8 + 4 + 2 + 1 =191
Class C
High Order Bit = 100
Value = 233
128 64 32 16 8 4 2 1
1 1 0 1 1 1 1 1
128 + 64 + 16 + 8 + 4 + 2 + 1 = 233
Private vs. Public Address
This Internet Assigned Names & Numbers Authority (IANA), has reserved three blacks of IP Address for private use on a network that will not be connected to the internet; They are:
10.0.0.0 => 10.255.255.255 Class A
127.16.0.0 => 172.31.255.255 Class B
192.168.0.0 => 192.168.255.255 Class C
The subnet mask identifies the network portion of an address. This portion is identified by all one and cannot be changed. The Host portion is identified by all zeros, athe selection can be changed.
Address Class Subnet Mask (Dec) Subnet Mask (Bin)
A 255.0.0.0 11111111.00000000.00000000.00000000
B 255.255.0.0 11111111. 11111111. 00000000.00000000
C 255.255.255.0 11111111. 11111111. 11111111.00000000
Formulas:
Number of host
(2-n – 2)
Number of Subnets
(2n - 2)
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Jun 17, 2003, 09:34 AM
#3
Re:Internet Addressing
IP
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Acronym for Internet Protocol. IP specifies the format of packets, also called datagrams.
Each set of numbers is called an Octet.
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An octet is 8 bits. It is equivalent to a byte, as long as the byte is also 8 bits. Bytes range from 4 - 10 bits, but octets are always 8 bits.
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So an IP address size is 4bytes or 32 bits.
IP addressing is coupled with some form of connection method between destination and source. FOr example on the internet we use TCP/IP which is Transmission Control Protocol/ Internet Protocol to govern the way we send an receive data.
more to come...
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