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Chapter 1: Support Resources for TroubleshootingNetwork Management Systems
Computer networks have become complex for several reasons. There are many different makes and models of devices. Most networks deploy a variety of protocols and applications. Several local-area, wide-area, and remote access technologies and techniques have been invented. Making all of these components work together reliably with maximum availability is not a trivial task. Network management systems are tools to help understand, monitor, troubleshoot, modify, scale, and secure networks.
The five key functional areas of network management, as per the International Organization for Standardization (ISO) definition, are
Fault management, a major troubleshooting topic, is about discovering abnormal behavior before or shortly after it happens. Once a problem is detected, take the following sequence of actions:
1 Determine the problem area.
2 Isolate the problem area and take advantage of alternate paths (complex networks usually have fault-tolerance and/or redundancy built in).
3 Attempt to minimize the impact of the failure(s).
4 Discover the specific device(s) causing the fault(s).
5 Identify the component/subsystem that is malfunctioning and needs to be replaced or reconfigured.
6 Implement the solution and pave the way for restoring the normal network operation.
NOTE: The systematic troubleshooting methodology that guides you from problem definition through discovery of the problem andimplementing the solution is discussed in Chapter 2, "Understanding Troubleshooting Methods."
The remainder of this section covers the following:
CiscoWorks is Cisco Systems' network management software. This software is based on Simple Network Management Protocol and it is for managing networks with one integrated platform. CiscoWorks provides services that have both operations and management value. Network managers can monitor routers (down to port activity), observe traffic patterns, modify configurations, observe and report inventory, capture data (for accounting purposes), and observe security settings all from their one central station. Some of the main components of CiscoWorks (classic-that is, prior to CiscoWorks 2000) are
There are other software applications, such as CiscoView, bundled with CiscoWorks. CiscoView is also available as a standalone product and can be integrated with other network management platforms such as SunNet Manager, HP OpenView, and IBM NetView. CiscoView is a GUI software that provides real-time device level monitoring (providing status and statistics information), fault management, and troubleshooting.
Another valuable network management tool is Cisco Resource Manager (CRM). CRM is web-based and among its components there are four essential applications: Inventory Manager, Availability Manager, Syslog Analyzer, and Software Image Manager. CRM complements CiscoView and other parts of CiscoWorks network management software.
CiscoWorks for Switched Internetworks Software
CWSI Campus is a suite of network management applications that together provide remote monitoring, configuration, and management of switched internetworks. The following are included in the CWSI Campus package:
For a description of these components, refer to www.cisco.com/univercd/cc/td/doc/ product/rtrmgmt/sw ntman/cwsimain/cwsi2/cwsiug2/gsg/gsin.htm at the Cisco Documentation site. CWSI can be integrated with other SNMP-based network management systems, such as SunNet Manager, HP OpenView, and IBM NetView. Protocols such as SNMP, Cisco Discovery Protocol (CDP), VLAN Trunking Protocol (VTP), and RMON form the foundation of the CWSI application suite. One of the valuable features of CWSI Campus is Network Map. This application provides a map of the physical devices and links in your network,which it automatically discovers, provided that there is a Cisco seed device present. You can then locate specific devices in the network and view how they are linked together. Network Map can also display the network virtual topology (virtual LAN configuration) in relation to the physical topology.
TrafficDirector Remote Monitoring Software
The TrafficDirector software is an application in the CWSI Campus suite of network management applications. This software allows you to monitor traffic (on network segments) leading to the diagnosis of any abnormalities. TrafficDirector obtains traffic information from embedded RMON agents (of Catalyst switches) and standalone Cisco SwitchProbe products. With this information, TrafficDirector can inform you of collisions, errors, utilization, and broadcast rates on a port (or port group) basis. You can also set up TrafficDirector to receive threshold-based traps from Catalyst switches. Hence, TrafficDirector is considered an excellent fault and performance management tool. Furthermore, since you can capture remote packets and profile network traffic on a multilayer basis, TrafficDirector is also considered a remote monitoring and traffic analysis tool.
Simulation and Modeling Tools
As the name implies, simulation and modeling tools are meant to allow you to put a network together (using the software) and see how it performs. You can use these tools to design a brand new network or to see how an existing network will perform if you modify it, expand it, or put traffic stress on it. Simulation tools allow you to select networking devices and interconnect them with a variety of serial, LAN media, dialup, and WAN services. You can configure the selected devices line by line or assign preexisting real configuration files to them, and analyze the simulated network's operation. If you have a network analyzer that can export captured data into a format that you can feed to your simulation software, you can then see how the simulated network behaves or reacts to the real traffic.
A useful function of simulation tools is reporting on throughput, utilization, response time, error rate, dropped packets, and other performance-related data during the simulation period. This capability is valuable for evaluating small or significant proposed changes before committing to them and, hence, can prevent financial and operational disasters. Additionally, the impact of failed segments and/or devices can be analyzed and used to evaluate options such as implementing fault tolerant devices, redundant links, or high capacity/reliable technologies. Cisco Netsys is a product that offers such services. The demonstration version of Netsys (installable on Windows NT platforms, for example) provides a video presentation about the capabilities of this software; furthermore, it provides you with a subset of the full version's capabilities for your evaluation.
Cisco Connection Online (CCO)
CCO provides a suite of interactive web-based services that offer open access to Cisco's information, systems, resources, and personnel-24 hours a day, 7 days a week, from anywhere in the world. Figure 1-4 displays CCO's home page (www.cisco.com).
The online/interactive services offered by Cisco over the Internet have evolved and grown over time. Today you have access to a wealth of technical knowledge, tips, bug information, support services, and other valuable resources all from one place. CCO is not only about obtaining information; you may, for example, access the online price list on Cisco products, place orders, download Cisco Internetwork Operating System (IOS) software images, or receive technical assistance and many other services. There are two levels of access available: guest access and registered access. Table 1-1 shows the benefits of each and how they relate to troubleshooting...