7.2 Monitoring the Network
7.2.1 Why is it necessary to monitor a network?
Although there are many reasons for network monitoring, the two primary reasons are predicting changes for future growth and detecting unexpected changes in network status. Unexpected changes might include things such as a router or switch failing, a hacker trying to gain illegal access to the network, or a communication link failure. Without the ability to monitor the network, an administrator can only react to problems as they occur, instead of preemptively preventing these problems from occurring. 

In the previous semester network management topics were covered with primary focus on Local Area Networking. Monitoring a Wide Area Network involves many of the same basic management techniques as managing a Local Area Network. One of the major differences in a WAN-LAN comparison is the physical placement of equipment. The placement and use of monitoring tools becomes critical to the uninterrupted operation of the Wide Area Network.