topology network exercise

There are around 8 topology network :

• Point-to-point
• Bus
• Star
• Ring or circular
• Mesh
• Tree
• Hybrid
• Daisy chain

Below showed 3 example topology  network  with advantages and disadvantages for the network. topology network are created to connect user in radius places with 1 network that even if the internet are broke down but still user can connect to each other and send file,document and items.

BUS TOPOLOGY

Bus networks (not to be confused with the system bus of a computer) use a common backbone to connect all devices. A single cable, the backbone functions as a shared communication medium that devices attach or tap into with an interface connector. A device wanting to communicate with another device on the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and processes the message.
Ethernet bus topologies are relatively easy to install and don't require much cabling compared to the alternatives. 10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") both were popular Ethernet cabling options many years ago for bus topologies. However, bus networks work best with a limited number of devices. If more than a few dozen computers are added to a network bus, performance problems will likely result. In addition, if the backbone cable fails, the entire network effectively becomes unusable.
See the illustration of Bus Network Topology.

Advantages of a Linear Bus Topology

• Easy to connect a computer or peripheral to a linear bus.
• Requires less cable length than a star topology.

Disadvantages of a Linear Bus Topology

• Entire network shuts down if there is a break in the main cable.
• Terminators are required at both ends of the backbone cable.
• Difficult to identify the problem if the entire network shuts down.
• Not meant to be used as a stand-alone solution in a large building.

TREE TOPOLOGY 

Tree topologies integrate multiple star topologies together onto a bus. In its simplest form, only hub devices connect directly to the tree bus, and each hub functions as the "root" of a tree of devices. This bus/star hybrid approach supports future expandability of the network much better than a bus (limited in the number of devices due to the broadcast traffic it generates) or a star (limited by the number of hub connection points) alone.
See the illustration of Tree Network Topology.

Advantages of a Tree Topology

• Point-to-point wiring for individual segments.
• Supported by several hardware and software venders.

Disadvantages of a Tree Topology

• Overall length of each segment is limited by the type of cabling used.
• If the backbone line breaks, the entire segment goes down.
• More difficult to configure and wire than other topologies. 

STAR TOPOLOGY

 Many home networks use the star topology. A star network features a central connection point called a "hub" that may be a hub, switch or router. Devices typically connect to the hub with Unshielded Twisted Pair (UTP) Ethernet.
Compared to the bus topology, a star network generally requires more cable, but a failure in any star network cable will only take down one computer's network access and not the entire LAN. (If the hub fails, however, the entire network also fails.)
See the illustration of Star Network Topology.

Advantages of a Star Topology

• Easy to install and wire.
• No disruptions to the network then connecting or removing devices.
• Easy to detect faults and to remove parts.

Disadvantages of a Star Topology

• Requires more cable length than a linear topology.
• If the hub or concentrator fails, nodes attached are disabled.
• More expensive than linear bus topologies because of the cost of the concentrators.

Individual Assignment!

Briefly explain about virus ( with examples) and find out the latest antiviruses in market.

there are lots of virus and boot that are can critically attack our computer. They can transfer from one computer to other. \its better the computer that are infected to be isolated from other computer.

"A Virus is defined as a program inserted into another program. It gets activated by its host program. It replicates itself and spreads to others through floppy transfer. A virus infects data or program every time the user runs the infected program and the virus takes advantages and replicates itself." Online Security"



"If the virus is found in any of the PC's that PC should immediately be isolated. The virus can be removed by giving an antidote by studying the virus. The machine should be put into use only after the virus is eliminated." Online Security.

one of example of virus is we called \"BOMB"
Bomb: This is also know as 'Logic Bomb' and 'Time Bomb'. An event triggered routine in a program that causes a program to crash is defined as a 'bomb'. Generally, 'bomb' is a software inserted in a program by a person working in the company.This virus create to perform and attack other on certain time and date.

Antivirus Software: What to Look For

All security software is not created equal. Like all consumer products, antivirus software has the good, the bad and the mediocre. The choices for antivirus protection are many and varied. We feature the best antivirus software available today from a number of providers and compare them. When it really comes down to it, effectiveness and usability can either make or break antivirus software. Our top-ranked antivirus software combine optimal security with user-friendly features and tools.
Below are the criteria Top Ten REVIEWS uses to evaluate and compare antivirus software:

Scope of Protection
While most security solutions tout multi-layered protection and 360-degree defense, some are more thorough than others. The best antivirus solutions will include traditional protection from viruses, worms, Trojans and spyware, but should also include defense from key loggers, phishing scams, email-borne threats and root kits. While antivirus programs are by no means full-blown internet security suites, they should protect from as many threats on as many fronts as they can.

Effectiveness
Antivirus is specifically designed to protect your computer, so if it doesn’t do that well, what good is it? All the features, bells and whistles and sleek interfaces can’t make up for poor performance. We look at results from the industry-standard security software testers and professional security organizations to find the most effective software available.

Ease of Installation and Setup
Security software shouldn’t be a chore to install and should have you protected as soon as possible. From download to install, to the first scan, implementing antivirus software should be quick and easy.

Ease of Use
Antivirus software is complex stuff, but shouldn’t require a degree in computer security. The best security programs have all the features security experts want, but are just as easiy for a beginner. Everyday computer users want a security solution that they can install and forget about; software that doesn’t require constant maintenance or have annoying interruptions. The best antivirus software is flexible enough to do exactly what you want to (even if that means running by itself).

Features
A well-rounded feature set takes a security solution from good to great. More than bells and whistles, added features provide security, usability and performance benefits.

Updates
Security software is only as good as its latest update. Viruses are being identified and added to signature databases all the time. So it’s important that your virus definition list updates accordingly. Modern antivirus software are equipped with automatic updates that perform regularly enough that you get faster updates that don’t slow down your system. The best security providers push updates to you as soon as they’re available.

Help & Support
The best software doesn’t require reading an in-depth manual to use, but still has one available. For specific questions, troubleshooting and additional help, the best antivirus manufacturers provide superior product support online and off. Additional support for software may come in the form of assistance over the phone, email, live chat or through a number of additional resources (knowledge base, FAQs, tutorials).

A well-balanced antivirus solution is effective, efficient and easy to use. Combining all the right features with a usable interface, our top antivirus software choices deliver the best security and usability without a serious investment in time, money or system resources.

Example for anti-virus are :