# Diagnosing Problems

When you first encounter a system problem:

1. Make sure power connections are secure attached.
2. Observe the system's LEDs carefully.
3. Make sure cable connections on the system modules are securely attached.

If a problem is beyond the scope of this chapter, see Contacting Customer Support and Returning Hardware for further instructions.

| Note: Running the show version, show hardware, and show environment commands is often a good first step when trying to troubleshoot a problem.

## Initialization Sequence

Each line module is initialized independently. As a result, the command-line interface (CLI) on the switch route processor (SRP) module might become available before the line modules have completed initialization. Commands relating to a line module might fail if the module has not completed initialization. Use the show version command to display line module status. Do not enter commands for a line module until its state is online.