Chapter 10. Maintenance, Monitoring, and Troubleshooting
The ability to maintain, monitor, and troubleshoot networks is important. You might design a switched LAN network that meets the requirements of the organization using the network today, but over time these requirements might exceed the current capabilities of your design. It is very important that you understand how to monitor and troubleshoot your network, ensuring that you can identify key issues in your network and resolve them quickly and efficiently.
To ensure the continuing operation and stability of your LAN switches, you must put in place mechanisms that allow for the fast restoration of configuration files and other files in the event of a switch failure or file corruption. Understanding how you can work with key files on your LAN switches in terms of transferring these files to and from other locations for both backup and restoration purposes is paramount in ensuring your ability to maintain the availability of the LAN network.
It is always important to put the LAN network in perspective; it exists to allow organizations to run network applications and permit the exchange of information vital to the ongoing operation of the organization. The ability to troubleshoot these network applications is vital; you might often need to view the traffic that is being transmitted between the end points of a network application to aid in troubleshooting a specific problem. Cisco Catalyst switches enable you to capture network traffic, even though traffic capture has been traditionally impossible to perform on a switch. In a switched environment, capturing traffic is difficult because the fabric that forms each broadcast domain is not shared and the traffic destined for a specific host on a specific switch port is not normally sent to any other ports. Traffic capture also enables you to monitor the performance of your network, looking for possible issues such as excessive broadcast and multicast traffic or an excess of corrupted frames.
In this chapter, you first learn about basic troubleshooting tools on Cisco IOS and then learn how to troubleshoot common issues on Cisco Catalyst switches. Next you learn how to maintain Cisco Catalyst switches, how to back up, recover, and upgrade configuration files and operating system files. Finally, you learn how to configure the various packet capture features provided on Cisco Catalyst switches. The following scenarios are presented in this chapter: