Cisco Systems CCNA 2 manual Network Testing, Observing multiple paths to destination

9.1.9 Observing multiple paths to destination

Some routing protocols support multiple paths to the same destination. Multipath algorithms permit traffic over multiple lines, provide better throughput, and are more reliable. Discuss with the students their ideas on why it would be better to have multiple paths through the network. Discuss redundancy and reasons why all networks are not redundant.

9.2 Network Testing

Essential Labs:	9.2.6
Optional Labs:	None
Core TIs:	All
Optional TIs:	none

Course-Level Claim: Students can use embedded Layer 3 through Layer 7 protocols to establish, test, suspend, or disconnect connectivity to remote devices from the router console.

Certification Level Claim: Students can describe network communications in layered models, perform simple LAN troubleshooting, and use the OSI model as a guide for systematic network troubleshooting.

Hands-on skills: none

9.2.1 Introduction to network testing

Basic testing of a network should move through each layer of the OSI reference model. Begin with Layer 1 and work to Layer 7 if necessary. Instruct the students to look for simple solutions first when they test a network. Some of the most common problems on IP network result from errors in the addressing scheme. Reinforce how important IP addressing schemes are to a network. Explain to students that a large part of their role in the workplace will require troubleshooting.

9.2.2 Using a structured approach to troubleshooting

Troubleshooting is a process that allows a user to find problems in a network. There should be a structured or orderly process to troubleshooting based on the networking standards defined by an administration. Documentation is a very important part of the troubleshooting process.

Emphasize to the students that documentation is important, but probably the least performed task in network management. Have the students brainstorm ideas about why a structured approach is important to troubleshooting. Discuss the ideas with the class.

Emphasize the two structured approaches explained in the curriculum. Since these are not the only two approaches, instruct the students to work in groups and develop their own structured approaches to troubleshooting. The students need to understand that the troubleshooting process can create additional problems. To prevent this, make sure students know that they should reverse any processes they use to solve the issue. Failure to do so can add to the network problems.

105 - 238 CCNA 2: Routers and Routing Basics v3.1 Instructor Guide – Module 9 Copyright ♥ 2004, Cisco Systems, Inc.