Introduction to Computer Networks Introduction to Computer Networks

Administering Change The lesson discusses how to document information about a running network.

Documenting a Running Network Preparing and maintaining network records are essential tasks that will pay off when you need to implement changes to a network.Preparing and maintaining network records are essential tasks that will pay off when you need to implement changes to a network. Documentation developed for maintenance, upgrading, and troubleshooting should contain:Documentation developed for maintenance, upgrading, and troubleshooting should contain: A map of the entire network, including the locations of all hardware and details of the cabling.A map of the entire network, including the locations of all hardware and details of the cabling. Server information, including the data on each server and the schedule and locations of backups.Server information, including the data on each server and the schedule and locations of backups.

Documentation Software information, such as licensing and support details.Software information, such as licensing and support details. Essential names and telephone numbers for vendors, suppliers, contractors, and other helpful contacts.Essential names and telephone numbers for vendors, suppliers, contractors, and other helpful contacts. Copies of all service agreements.Copies of all service agreements. A record of all problems, their symptoms and solutions, including dates, contacts, procedures, and results.A record of all problems, their symptoms and solutions, including dates, contacts, procedures, and results.

Establishing a Baseline A baseline is simply a documentation of the network's normal operating values.A baseline is simply a documentation of the network's normal operating values. The baseline is especially helpful in establishing and identifying: The baseline is especially helpful in establishing and identifying: Daily network-utilization patterns. Daily network-utilization patterns. Bottlenecks. Bottlenecks. Heavy-usage patterns. Heavy-usage patterns. Different protocol traffic patterns. Different protocol traffic patterns.

Documenting Network Performance The concept of network performance is a broad one that encompasses the entire network, including:The concept of network performance is a broad one that encompasses the entire network, including: Servers. Network interface cards (NICs). Cable connections to the NICs. Hubs. Cable runs. Routers. RJ-45 wall plates. Workstation NICs. Servers. Network interface cards (NICs). Cable connections to the NICs. Hubs. Cable runs. Routers. RJ-45 wall plates. Workstation NICs.

Network Monitors A network monitor is a useful tool that captures and filters data packets and analyzes network activity.A network monitor is a useful tool that captures and filters data packets and analyzes network activity. It is easy to document the network performance indicators with a network monitor, but it takes extra practice to quickly analyze the network performance statistics.It is easy to document the network performance indicators with a network monitor, but it takes extra practice to quickly analyze the network performance statistics. Some network operating systems include network monitoring software among their resources, and a number of other software manufacturers also offer network monitors.Some network operating systems include network monitoring software among their resources, and a number of other software manufacturers also offer network monitors.

Protocol Analyzers A protocol analyzer is a tool that keeps track of network statistics.A protocol analyzer is a tool that keeps track of network statistics. It can capture bad frames and isolate their source. It can capture bad frames and isolate their source. A protocol analyzer can be helpful for a company that has a large network with a highly trained staff.A protocol analyzer can be helpful for a company that has a large network with a highly trained staff. Protocol analyzers can be inexpensive software programs that run on existing networked computers.Protocol analyzers can be inexpensive software programs that run on existing networked computers.

Other Software Tools PingPing TracertTracert IpconfigIpconfig NetstatNetstat

Bottlenecks (1) Most network activities involve the coordinated actions of several devices.Most network activities involve the coordinated actions of several devices. Each device takes a certain amount of time to perform its part of the transaction.Each device takes a certain amount of time to perform its part of the transaction. Poor performance results when one of these devices uses noticeably more CPU time than the others.Poor performance results when one of these devices uses noticeably more CPU time than the others. The problem device is referred to as a bottleneck. Performance monitoring can help identify and eliminate bottlenecks.The problem device is referred to as a bottleneck. Performance monitoring can help identify and eliminate bottlenecks.

Bottlenecks (2) These devices tend to become bottlenecks:These devices tend to become bottlenecks: CPUs Memory Network cards Disk controllers Network mediaCPUs Memory Network cards Disk controllers Network media Proper monitoring will uncover these situations and provide information to help identify the problem component or components.Proper monitoring will uncover these situations and provide information to help identify the problem component or components.

Total System Management System-management software provides centralized administration of computers in a WAN. This service includes:System-management software provides centralized administration of computers in a WAN. This service includes: Collecting hardware and software inventory information.Collecting hardware and software inventory information. Distributing and installing software.Distributing and installing software. Sharing network applications.Sharing network applications. Troubleshooting hardware and software problems.Troubleshooting hardware and software problems.

Maintaining a Network History Documenting a network's history is as important as monitoring its real-time performance. A network's written record can:Documenting a network's history is as important as monitoring its real-time performance. A network's written record can: Indicate significant performance or equipment issues that real-time monitoring might miss.Indicate significant performance or equipment issues that real-time monitoring might miss. Provide a background against which current information can be compared.Provide a background against which current information can be compared.