chapter 9: Communicating Securely Over Network Connections
What is Network ?
A network consists of computers and other electronic devices that are connected to each other over a transmission medium. The transmission medium can be cable (copper or optical fibre), Wi-Fi, radio waves, infrared waves, or a satellite. There are many benefits of computer networks such as higher speed, reduced cost, enhanced security, flexible access, email access, and centralised software and hardware management.
On the basis of Size, networks are classified under the following Categories
Local Area Network (LAN)
It is a network that is confined to a small geographical area such as a school, office, or multiple offices within a campus. However, a single LAN can be connected to other LANs over long distance via telephone lines and radio waves. The LAN is a private network which can restrict communication to the nodes within the network and prevent it from reaching the Internet.
Metropolitan Area Network (MAN)
MAN is a large, high-speed computer network that usually spans a large campus or an entire city. A MAN usually interconnects multiple LANS using high-capacity fibreoptical links. MAN COvers the geographical area larger than the LAN but smaller than the area covered by a WAN . Companies that use MAN usually have several branches within a city such as banks, local IsPs, cable television companies and local telephone companies. Metro Ethernet is one of the latest forms of MAN.
Wide Area Network (WAN)
It is a network that spans over a large geographical area, such as a country or the entire world. A WAN can contain multiple smaller networks, such as LANs and MANs. WANs are used by large organisations to interconnect LANs at offices in different countries. The Internet is the biggest public WAN and a network of ATMs is a private WAN.
Virtual Private Network (VPN)
It is a type of network that allows computers or an entire network to connect to each other over the Internet securely. VPN is based on the client-server architecture so it consists of a VPN client and VPN server and the software that enables secure connections. VPN uses different security tools such as tunnelling protocol. The tunnelling protocol creates a tunnel between two devices and encrypts all the information in the tunnel.
Home Area Network (HAN)
HAN is a network that connects all devices in your home to the Internet and to each other. These devices include desktop computer, laptop, mobile phone, tablet, printer and gaming system. You can set up a home network to perform the following tasks:
Threats to Wireless Networks
Misconfiguration: Many novice users deploy their wireless networks on their own using default unsecured configurations. This makes t possible for hackers to gain easy access to their networks, hard drives and use resources such as Internet connections. To correctly configure your wireless router, you must always read the instructions manual that came with it
Evil Twin: An evil twin is a (rogue) wireless network access point that imperson ates as a legitimate wireless access point. Hackers create evil twins to trick users looking for tree Internet connections. The evil twin looks like a hot spot with a very strong signal that attracts users to connect to it. Once users log in, they become susceptible to attacks of various kinds.
War Driver: The act of searching for unsecured W-Fi networks by an individual in a moving vehicle, using a computer and an 802.11 wireless LAN adapter is called war driving. This is done to gain unauthorised access to computers on the non-secure WE-Fi network. This attack can be pertormed by the war driver within the range of the router
How to secure you network
Firewall:
Antivirus:
Encryption:
Browsing only secure website:
Lock icon:
URL :
