This module examined troubleshooting techniques and common problems
associated with the following Layer 2 protocols and technologies:
- Switches and switched technologies
- PPP
- ISDN
- Frame Relay
The difficulty in troubleshooting these technologies is the inability
of common Layer 3 troubleshooting tools, such as ping, to assist with anything
but the identification that the network is down. It is only through a thorough
understanding of the protocols and their operation that a network technician
will be able to choose the appropriate troubleshooting methodology and IOS
commands to solve the problem in an efficient manner.
In the case of
switched networks, it is possible to design a functional but suboptimal
network. With no apparent network failure, it will only be the awareness of
common problems and the ability of a network technician to identify Layer 2
traffic paths that will allow the network technician to achieve the full
performance a network is capable of.
After completing this module, the
students should be confident that they can recognize common Layer 2 problems
and address them quickly and accurately.