As corporate intranets continue to grow, it is becoming increasingly important for network administrators to be aware of the different types of traffic that run through their networks. Traffic monitoring and analysis is essential to be able to solve and solve problems more effectively when they occur, so as not to bring network services to a stop for long periods of time. Numerous tools are available to assist administrators with monitoring and analyzing network traffic. This article discusses routing-based monitoring techniques and monitoring techniques based on non-routers (passive versus active). It provides an overview of the three most commonly used routers based network monitoring tools (SNMP, RMON and Cisco Netflow) and provides information on two most recent monitoring methods using a combination of passive and active monitoring techniques (WREN and SCNM ).