Networking
An internetwork is a collection of individual network,connected by intermediate networking devices, such as routers and switches that function as a single large network.
Inter-networking is a term used by Cisco, and other providers of network products and services as a comprehensive term for all the concepts, technologies, and generic device that allow people and their computers to communicate across different kind of network,For example, someone at a computer on a Token Ring local area network may want to communicate with someone at a computer on an Ethernet local area network in another country using a wide area network interconnection.
The common internetwork protocols, routing tables, and related network devices required to achieve this communication constitute inter-networking.
Inter-networking is a term used by Cisco, and other providers of network products and services as a comprehensive term for all the concepts, technologies, and generic device that allow people and their computers to communicate across different kind of network,For example, someone at a computer on a Token Ring local area network may want to communicate with someone at a computer on an Ethernet local area network in another country using a wide area network interconnection.
The common internetwork protocols, routing tables, and related network devices required to achieve this communication constitute inter-networking.
IP Addressing
IP address is numeric identifier assigned to each computer or device on a TCP/IP network. It designates the specific location of a device on the network. It allows hosts on one network to communicate with a host on different network regardless of type of LANs. An IP address is a software (logical) address not a hardware address like MAC.
Basic IP Terminologies
- Bit :- A bit is one digit either a 1 or a 0.IP
- Byte :- A Byte is 8-bits or digits. Octet :- An octet is made up of 8-bits binary number. The term byte and octet are completely interchangeable.
| FIGURE :-The Structure of IPv4 addresses |
| The computer using this IP address is on network 192.168.10.0 |
Hexadecimal is not used as often as dotted-decimal, only Windows Registry stores machines IP in hexadecimal. The advantage of hierachical address is that it can handle a large number of addresses, namely 4.3 billion.
Without the IP address, information cannot be received. IP addresses may either br assigned permanently (static IP) or temporarily (dynamic IP). Dynamic IP is assigned by DHCP server from a range of available addresses,with the first serve basis.
Without the IP address, information cannot be received. IP addresses may either br assigned permanently (static IP) or temporarily (dynamic IP). Dynamic IP is assigned by DHCP server from a range of available addresses,with the first serve basis.
| FIGURE :-Binary Weight of each bit |
Octet (8-Bits) |
| FIGURE :-IP Address Format |
 |
IP Address Classes
IP address is short for Internet Protocol (IP) address.An IP address is an identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination.
When IP was First Developed, No classes of addresses are exist, Bur as the number of network grew, the IP addresses were broken into categories called Classes. IP addresses are divided into five callsses,
Each of which is designated with the alphabetic letters A to E.
When IP was First Developed, No classes of addresses are exist, Bur as the number of network grew, the IP addresses were broken into categories called Classes. IP addresses are divided into five callsses,
The key to understanding IP, and all of the issues related to IP, is knowing what a routing table looks like and the effects each IP topic has on the entries in a routing table. To begin with, let's review the basics.
IP addresses are 32 bit numbers, most commonly represented in dotted decimal notation (xxx.xxx.xxx.xxx). Each decimal number represents eight bits of binary data, and therefore can have a decimal value between 0 and 255. IP addresses most commonly come as class A, B, or C. It's the value of the first number of the IP address that determines the class to which a given IP address belongs. Class D addresses are used for multi-cast applications.
Table describes how IP address classes are organized.
Class
|
Network Portion
|
Hosts Allowed
|
|---|---|---|
A
|
from 1.0 to 127.0
|
approx. 16 million
|
B
|
from 128.0 to 191.255
|
65,536
|
C
|
from 192.0 to 223.255.255
|
255
|
Class A
Address Range
The first bit of first octet in a Class A network address must always be 0(ZERO). It other 7 bits all are turned off and then all on , Class A network address range will be found. This means a Class A address must be between 0 and 127 in the first octet.
Addresses
In a Class A network address, the first octet is assigned to the network - address and the remaining three octet are used for the HOST-addresses.
Subnet Masks
A subnet mask tells a router how much of an address it should treat as the network portion. The masks for traditional Class A, B and C networks are shown below in Table -2
Table -2 Standard IP Subnets
Comparing the masks above to the first chart, you can see that the 255s in a mask identify the network portion of the address.
Just as the masks above specify what portion of the global IP address range a network is using, a subnet mask can also be used to subdivide a Class A, B or C network range into multiple groups of hosts, or "subnets."
This is done by telling the router that more than the traditional number of bits in the mask are to be treated as the network portion of the address. Table -3 shows all of the possible Class C subnet masks, and how many hosts are then allowed on each subnet.
Table -3 Subnetted Class C Host Ranges
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