Step 1—Understand How Basic Initialization Works
8Cisco IOS Release 12.0(5)T
Troubleshooting Steps
To troubleshoot a malfunctioning cable modem, perform the following tasks:
•Step 1—Understand How Basic Initialization Works
•Step 2—Connect to the Cisco uBR924
•Step 3—Display the Cisco uBR924’s MAC Log File
•Step 4—Interpret the MAC Log File and Take Action
•(Optional) Step 5—Use Additional Troubleshooting Commands

Step 1—Understand How Basic Initialization Works

Before you troubleshoot a Cisco uBR924 cable access router, you should be familiar with the cable
modem initialization process. See Figure 2 and Table1. Understanding this flowchart and sequence
of events will help you determine where and why connections fail.
The sequence numbers shown in Figure2 are explained in Table 1, which appears after the
illustration. The Cisco uBR924 will complete all the steps in this flowchart each time it needs to
reestablish ranging and registration with the CMTS.