The only Cisco authorized textbook for the CCNP 4 Network Troubleshooting course in the Networking Academy Portable desk reference that supports the online course Customized test engine and other components of the CD-ROM help students prepare for the CCNP Troubleshooting exam Written by the curriculum developers to provide you with information straight from the source This is the first edition of the Network Troubleshooting Companion Guide for students enrolled in the CCNP 4 Network Troubleshooting Cisco Networking Academy Program course. The book is specifically designed to supplement the CCNP 4 online course version 3.0 and to prepare readers for the updated CIT exam. This book provides a detailed analysis of network troubleshooting for LANs and WANs. Topics include documentation, baselining, troubleshooting tools, troubleshooting methodologies, and per-OSI-layer troubleshooting techniques. This Companion Guide, combined with the Cisco Networking Academy Program CCNP 4- Network Troubleshooting Lab Companion, prepares students for the Cisco Internet Troubleshooting Support (CIT) exam. CIT is a qualifying exam for the CCNP certification. The CIT exam certifies that the successful candidate has important knowledge and skills necessary to troubleshoot sub-optimal performance in a converged network environment. The exam covers topics on establishing a baseline, determining an effective troubleshooting strategy, resolving problems at the physical and data link layers, resolving problems at the network layer, and resolving problems at the transport and application layers. .