Showing posts with label networks. Show all posts
Showing posts with label networks. Show all posts

Friday, March 23, 2012

Networking Fundamentals


Computer Networking is any set of computers or devices connected to each other so as to communicate or exchange data. For a network to function, the devices must be interconnected. Network connections can be wired or wireless.

All networks are connected to enable communication with different kinds of media (wire or cables), which includes, twisted-pair copper wire cable, coaxial cable, optical fiber, power lines and various wireless technologies.

The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet).

In Wired networks, the medium is either copper, which carries electrical signals, or optical fibre, which carries light signals.

In Wireless networks, the medium of connection or mode of transmitting is radio waves, space, or microwaves. Wireless networks may include the home wireless connection between a wireless router and a computer with a wireless network card, the global wireless connection between two ground stations, or the communication between devices on earth and satellites then received via the internet.

Examples of Networks are:
Local Area Network. (LAN)
A LAN (Local Area Network) is an individual network that covers a single geographical area, providing networking services and applications to people within a common managerial structure, such as a single business, campus or region.

A LAN is usually administered by a single organization. The administrative control that governs the security and access control policies are enforced on the network level. LANs and WANs are very useful to individual organizations. They connect the users within the organization. They allow many forms of communication including exchange e-mails, corporate training, and other resource sharing. 

Wide Area Network. (WAN)
WAN that is usually a larger network that covers a large geographic area. An example of this is an organization that uses a WAN to interconnect their offices in different countries. The largest and best example of a WAN is the Internet, which is a network of networks, composed of many smaller networks. The Internet is considered the largest network in the world.

Main Features of WANs:
  • WANs generally connect devices that are separated by a broader geographical area than can be served by a LAN.
  • WANs use the services of carriers, such as telephone companies, cable companies, satellite systems, and network providers.
  • WANs use serial connections of various types to provide access to bandwidth over large geographic areas.

Wireless LANs and WANs. (WLAN & WWAN)
WLAN & WWAN are the wireless equivalent of the LAN and WAN. But there are no wires between end devices and servers. Communication or data is transferred over sets of radio transceivers or waves. These types of networks are beneficial when it is too costly or inconvenient to run the necessary cables.. The media access protocols for LANs come from the IEEE.

Components of the Network
The path that a message takes from source to destination can be as simple as a single cable connecting one computer to another or as complex as a network that literally spans the globe. This network infrastructure is the platform that supports our human network. It provides the stable and reliable channel over which our communications can occur.

Devices and Media
Devices and media are the physical elements or hardware of the network. Hardware is often the visible components of the network platform such as a laptop, a PC, a Switch, Router or the cabling used to connect the devices. Occasionally, some components may not be so visible. In the case of wireless media, messages are transmitted through the air using invisible radio frequency or infrared waves.

More Networking info you can visit: http://blog.router-switch.com/

Monday, March 12, 2012

Types of Firewalls: Hardware Firewalls & Software Firewalls

Firewalls can be Either Hardware or Software. The ideal firewall configuration will consist of both. In addition to limiting access to your computer and network, a firewall is also useful for allowing remote access to a private network through secure authentication certificates and logins.

While many people do not completely understand the importance and necessity of a firewall, or consider it to be a product for businesses only, if your network or computer has access to the outside world via the Internet then you need have a firewall to protect your network, individual computer and data therein.

Hardware firewalls can be purchased as a stand-alone product but more recently hardware firewalls are typically found in broadband routers, and should be considered an important part of your system and network set-up, especially for anyone on a broadband connection. Hardware firewalls can be effective with little or no configuration, and they can protect every machine on a local network. Most hardware firewalls will have a minimum of four network ports to connect other computers, but for larger networks, business networking firewall solutions are available.

A hardware firewall uses packet filtering to examine the header of a packet to determine its source and destination. This information is compared to a set of predefined or user-created rules that determine whether the packet is to be forwarded or dropped.

As with any electronic equipment, a computer user with general computer knowledge can plug in a firewall, adjust a few settings and have it work. To ensure that your firewall is configured for optimal security and protect however, consumers will no doubt need to learn the specific features of their hardware firewall, how to enable them, and how to test the firewall to ensure its doing a good job of protecting your network.

Not all firewalls are created equal, and to this end it is important to read the manual and documentation that comes with your product. Additionally the manufacturer's Web site will usually provide a knowledgebase or FAQ to help you get started. If the terminology is a bit too tech-oriented, you can also use the Webopedia search to help you get a better understanding of some of the tech and computer terms you will encounter while setting up your hardware firewall.

To test your hardware firewall security, you can purchase third-party test software or search the Internet for a free online-based firewall testing service. Firewall testing is an important part of maintenance to ensure your system is always configured for optimal protection.

Software Firewalls
For individual home users, the most popular firewall choice is a software firewall. Software firewalls are installed on your computer (like any software) and you can customize it; allowing you some control over its function and protection features. A software firewall will protect your computer from outside attempts to control or gain access your computer, and, depending on your choice of software firewall, it could also provide protection against the most common Trojan programs or e-mail worms. Many software firewalls have user defined controls for setting up safe file and printer sharing and to block unsafe applications from running on your system. Additionally, software firewalls may also incorporate privacy controls, web filtering and more. The downside to software firewalls is that they will only protect the computer they are installed on, not a network, so each computer will need to have a software firewall installed on it.

Like hardware firewalls there is a vast number of software firewalls to choose from. To get started you may wish to read reviews of software firewalls and search out the product Web site to glean some information first. Because your software firewall will always be running on your computer, you should make note of the system resources it will require to run and any incompatibilities with your operating system. A good software firewall will run in the background on your system and use only a small amount of system resources. It is important to monitor a software firewall once installed and to download any updates available from the developer.

The differences between a software and hardware firewall are vast, and the best protection for your computer and network is to use both, as each offers different but much-needed security features and benefits. Updating your firewall and your operating system is essential to maintaining optimal protection, as is testing your firewall to ensure it is connected and working correctly.

More Notes: Cisco news, Cisco info and Cisco tips and How to's you can visit: http://blog.router-switch.com/