Chapter Summary

Knowing how to troubleshoot network connectivity is an important part of a network administrator's role. Fortunately, many utilities are designed to make the process of determining and correcting connectivity issues easier. The most common utilities for this type of troubleshooting include ping, ipconfig, trace route, nbstat, and netstat. Variations of these commands are available on each of the major operating systems.

Today, small offices and home networks alike rely on Internet access for business and/or recreation. There are many different ways to get Internet access, including using xDSL, cable, home satellite, wireless, and POTS.

The DSL family of products is referred to as xDSL and includes ADSL, RADSL, IDSL, SDSL, HDSL, and VHDSL. Each DSL method is used for different applications. Only asymmetric DSL flavors such as ADSL and RADSL can share lines with a regular phone line. DSL is an always-on type of Internet access, which means a computer that uses it could be subjected to security risks from the outside.

Cable Internet is becoming increasingly popular because it offers fast and reliable transfer speeds. Cable Internet is widely available from most cable TV companies. Both wireless and home satellite Internet access target a very specific market. Wireless is used when mobility is required, and home satellite is used where other forms of Internet access are not available. POTS is regular modem Internet access; the maximum Internet speed available on POTS is 56Kbps.

How you troubleshoot each type of Internet connectivity depends on the exact type being used. General troubleshooting guidelines include using observation techniques, confirming physical connectivity, and verifying the protocol configuration.

As an administrator in today's networks, you will probably find yourself troubleshooting remote connectivity errors. Three common troubleshooting areas for remote access include authentication failure, protocol configuration problems, and physical connectivity problems. Before calling for technical support, network administrators should verify functionality in each of these areas.