WHAT IS NETWORK OR I.P. ADDRESS?

NETWORK ADDRESS

It is more commonly known as IP address.  It is the numeric address of a computer connected to the network. It can be compared to the physical address that we use for our homes which uniquely identifies it from the rest of the homes in our neighborhood, town, city, province, country and the whole wide world.

Also is a set of numbers, called as “octets” or “dotted decimal” notation, that identifies any network device.

IP Versions

IPv4 – Internet Protocol version 4 known as "standard version".

It is canonically represented in dotted-decimal notation, which consists of four decimal numbers, each ranging from 0 to 255, separated by dots, e.g., 172.16.254.1. Each part represents a group of 8 bits (octet) of the address.'

IPv6 – Internet Protocol version 6 known as "advanced version".

CLASSES OF IP ADDRESS

Class A - 1 to 126

Class B - 128 to 191

Class C - 192 to 223

Class D - 224 to 239

Class E - 240 to 255

Note:  127 – Loop back function of a network Class D - is for multicast Class E - reserved for future or experimental purposes

CREATING IP ADDRESS 

1.  Right click My Network Places

2.  Click Properties

3.  Right click Local Area Connection

4.  Click Properties

5.  Click TCP/IP

6. Click Properties           Obtain an IP address automatically           Use the following IP address

7.  Click OK

IP CONFIGURATION

1.  Click Start button

2.  Click Run

3.  Type cmd

4.  Type ipconfig

5.  Type ping [IP address]

WHAT IS THE DIFFERENCE BETWEEN STRAIGHT THROUGH AND CROSS-OVER CABLE?

Connecting a UTP cable involves the use of a RJ 45 connector.  This is an eight-wire connector commonly used to connect devices onto a local area network (LAN)

We need to use the correct color for the appropriated pin in the RJ-45 jack as shown in the table below.

PIN	T568 A	T568 B
1	White/Green	White/Orange
2	Green	Orange
3	White/Orange	White/Green
4	Blue	Blue
5	White/Blue	White/Blue
6	Orange	Green
7	White/Brown	White/Brown
8	Brown	Brown

 

  1.   Straight Through

-   It is used to connect different type of devices.

Example:

Computer – Switch

Switch – Router

Router - Computer

It uses A-A and B-B coding. 

    

    2.   Cross-Over

-   It is used to connect same type of devices.

Example:

Computer – Computer

Switch – Switch

Router - Router

It uses A-B coding.

WHAT ARE THE DIFFERENT TYPES OF CABLE?

WHAT IS A CABLE?

Cable - it is a medium that connects computer in a network

TYPES OF CABLE

1.    Twisted-pair cable

- Is the most common type of cable.

- Have eight individual copper wires bundled together and covered with an insulating material.

- The copper wire is always color-coded with plastic insulations and they are twisted in pairs for a total of four pairs.

a.     STP – Shielded Twisted Pair

- Often used in “noisy” environments where a shield of metallic foil is wrapped around each of the wire pairs, with an additional overall shielding to protect against   excessive electromagnetic interference.

b. UTP – Unshielded Twisted Pair

-   Is the most common form of twisted pair wiring.

-   It is less expensive and easier to work with than STP.

2.    Coaxial Cable

- the standard media used by cable TV operators.

- it consists of a plastic insulator that separates the solid copper inner conductor and the woven, copper braid outer conductor.

   

   3.    Fiber-optic Cable

-   has a reflective coating that allows light beams to travel without outer interference.

WHAT ARE THE DIFFERENT NETWORKING DEVICES?

Hub

A common connection point for devices in a network. Hubs are devices commonly used to connect segments of a LAN. The hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switch

A hardware device that channels incoming data from multiple input ports to a specific output port that will take it toward its intended destination. It is a small device that transfers data packets between multiple network devices such as computers, routers, servers or other switches.

Router

A hardware device designed to receive, analyze and move incoming packets to another network. It may also be used to convert the packets to another network interface, drop them, and perform other actions relating to a network. The picture shows the Linksys BEFSR11 wireless router and is what many home routers resemble.

Bridge

A type of computer network device that provides interconnection with other bridge networks that use the same protocol. Bridge devices work at the data link layer of the Open System Interconnect (OSI) model, connecting two different networks together and providing communication between them.

Networking Interface Card

A computer hardware component that connects a computer to a computer network. Early network interface controllers were commonly implemented on expansion cards that plugged into a computer bus.

 

Modem

A device which converts the computer-generated digital signals of a computer into analog signals to enable their travelling via phone lines. The 'modulator-demodulator' or modem can be used as a dial up for LAN or to connect to an ISP.

 

Transceivers

A group of transceivers comprising both a transmitter and a receiver which are combined and share common circuitry or a single housing. When no circuitry is common between transmit and receive functions, the device is a transmitter-receiver. The term originated in the early 1920s.

Firewall

A network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and entrusted external network, such as the Internet. 

WHAT IS A NETWORK TOPOLOGY?

Network Topology refers to layout of a network. How different nodes in a network are connected to each other and how they communicate is determined by the network's topology. Network Topology refers to the layout of a network and how different nodes in a network are connected to each other and how they communicate.

TYPES OF NETWORK TOPOLOGY

1. Bus Topology

In networking a bus is the central cable -- the main wire -- that connects all devices on a local-area network (LAN). It is also called the backbone. This is often used to describe the main network connections composing the Internet.  Bus networks are relatively inexpensive and easy to install for small networks. 

Main Advantage:  It's easy to connect a computer or device and typically it requires less cable than a star topology.

Main Disadvantage: The entire network shuts down if there is a break in the main wire and it can be difficult to identify the problem if the network shuts down.

2. Star Topology

In a star network devices are connected to a central computer, called a hub. Nodes communicate across the network by passing data through the hub.

Main Advantage: In a star network, one malfunctioning node doesn't affect the rest of the network.
Main Disadvantage: If the central computer fails, the entire network becomes unusable.

 3. Ring Topology

A local-area network (LAN) whose topology is a ring. That is, all of the nodes are connected in a closed loop. Messages travel around the ring, with each node reading those messages addressed to it. 

Main Advantage: One main advantage to a ring network is that it can span larger distances than other types of networks, such as bus networks, because each node regenerates messages as they pass through it.

4. Mesh Topology

In a mesh network, devices are connected with many redundant interconnections between network nodes. In a true mesh topology every node has a connection to every other node in the network. There are two types of mesh topologies:

Full mesh topology: occurs when every node has a circuit connecting it to every other node in a network. Full mesh is very expensive to implement but yields the greatest amount of redundancy, so in the event that one of those nodes fails, network traffic can be directed to any of the other nodes. Full mesh is usually reserved for backbone networks.

Partial mesh topology: is less expensive to implement and yields less redundancy than full mesh topology. With partial mesh, some nodes are organized in a full mesh scheme but others are only connected to one or two in the network. Partial mesh topology is commonly found in peripheral networks connected to a full meshed backbone.

5. Hybrid Topology

A hybrid topology is a type of network topology that uses two or more differing network topologies. These topologies include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology.

Advantages: It is extremely flexible, very reliable, and easily scalable

Disadvantages: It is expensive, the design of a hybrid network is complex and hardware changes are required in order to connect topology to another topology.