NETWORK SECURITY

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INTRODUCTION TO NETWORK SECURITY

What is a Network?
Computer Network is simply interconnected collection of autonomous computers. These computers can communicate with each other. Also they can exchange the information.
There are different types of networks such as LAN (local area network), WAN (wide area network) and MAN (metropolitan area network).These networks are having different topologies. Firstly network was used by researchers for mail sending and by some corporate employees for sharing printers, etc. So at those times security was not an important issue. But now a day’s security is the most important.


What is Security?
Security is a broad topic concerned with making sure that no other people cannot read, or modify messages intended for other recipients. It is concerned with people trying to access remote services that are not authorized to them.
Security is a very difficult topic. Everyone has a different idea of what ``security'' is, and what levels of risk are acceptable. The key for building a secure network is to define what security means to your organization.


Application Gateways
Application gateways are sometimes known as proxy gateways made up of bastion hosts that run special software to act as a proxy server. This software runs at the Application Layer of our old friend the ISO/OSI Reference Model, hence the name. These are also typically the slowest, because more processes need to be started in order to have a request serviced.

Packet Filtering
Packet filtering inspects each packet passing through the network and accepts or rejects it based on user-defined rules. Although difficult to configure, it is fairly effective and mostly transparent to its users. It is susceptible to IP spoofing.


Conclusion

Network security is a complicated subject, historically only tackled by well-trained and experienced experts. However, as more and more people become ``wired'', an increasing number of people need to understand the basics of security in a networked world. We have to consider risk management, network threats, firewalls, and more special-purpose secure networking devices. Understanding the reasons of insecurity and trying to avoid those reasons and solving them so as to provide secure networks are a must.