Chapter 12Introduction to Network Security
12.1 Introduction
Security concerns are very important in IP networks because such networks are inherently nonsecure. In this lecture, we first examine the types of attacks that can be launched on IP networks. We then examine the security mechanisms used in IP networks. Finally, we discuss the IP security (IPSec) protocol.
12.2 Types of Network Attacks
A network attack is an intrusion on a network infrastructure. The attacker first analyzes the environment and collects information in order to exploit the existing open ports or vulnerabilities. In some cases, the purpose of attack is only to learn and get some information from the system without altering or disabling it; this is referred to as a passive attack. In other cases called active attacks, the attacker accesses network resources to alter, disable, or destroy them. An attack can be performed either from outside of the organization by an unauthorized entity or from within the company by an “insider” that already has some access to the network.
There are different types of attacks that can be launched in a network. The following are some of the common ones:
- a. Network sniffing (packet sniffing) is a process of capturing the data packets traveling in the network. It is used by IT professionals to analyze and monitor the traffic to find such things as unexpected suspicious traffic. It is also used by attackers to collect data sent in clear text that is easily readable. In this ...