Troubleshooting guide

Troubleshooting TCP/IP
5-81
Introduction
This chapter provides troubleshooting solutions to some common TCP/IP
internetwork problems:
• Resolving Host Connectivity Problems
• Handling Routing Problems
• Misconfigured Router
• Handling a Misconfigured Access List
• Access List and Filter Misconfigurations
• Handling UDP Broadcast Forwarding Problems
• Resolving PPP Link Over SONET Failures
Resolving Host Connectivity Problems
The following sections provide instructions for resolving local and remote host
connectivity problems:
• Default Gateway Configuration Problems
• Misconfigured or Missing Default Routes
• Incomplete DNS Host Table
• DNS Not Running
Default Gateway Configuration Problems
If a local host cannot access a remote host, the default gateway might not be
specified, or the default gateway could be incorrectly configured on local or
remote host.
Note: This chapter presents host configuration solutions from a UNIX
perspective. If you are working with a PC, consult the corresponding
documentation to determine how to set the default gateway IP address.