Troubleshooting Tips
10
Release 11.3(4)NA
You can display other aspects of the MAC layer by using variations of the show controller
cable-modem 0 mac command:
uBR904# show controller cable-modem 0 mac ?
errors Mac Error Log data
hardware All CM Mac Hardware registers
log Mac log data
resets Resets of the MAC
state Current MAC state
For examples and descriptions on how to use these keywords, see the show controller cable-modem
mac command reference page.
Interpret the MAC Log File and Take Action
The MAC log file explains a detailed history of initialization events that occurred in the cable
modem. All pertinent troubleshooting information is stored here.
The following sample log file is organized by chronological sequence event. Sample comments are
also included.
• Event 1—Wait for the Link to Come Up
• Event 2—Scan for a Downstream Channel then Synchronize
• Event 3—Obtain Upstream Parameters
• Event 4—Start Ranging for Power Adjustments
• Event 5—Establish IP Connectivity
• Event 6—Establish the Time of Day
• Event 7—Establish Security
• Event 8—Transfer Operational Parameters
• Event 9—Perform Registration
• Event 10—Comply with Baseline Privacy
• Event 11—Enter the Maintenance State
Event 1—Wait for the Link to Come Up
The MAC layer informs the cable modem’s drivers that it needs to reset. This is the first event that
happens after the modem powers up and begins initialization. The fields
LINK_DOWN and LINK_UP are
similar to a shut and no shut on a standard Cisco interface.
uBR904# show controller cable-modem 0 mac log
528302.040 CMAC_LOG_LINK_DOWN
528302.042 CMAC_LOG_RESET_FROM_DRIVER
528302.044 CMAC_LOG_STATE_CHANGE wait_for_link_up_state
528302.046 CMAC_LOG_DRIVER_INIT_IDB_SHUTDOWN 0x08098D02
528302.048 CMAC_LOG_LINK_DOWN
528308.428 CMAC_LOG_DRIVER_INIT_IDB_RESET 0x08098E5E
528308.432 CMAC_LOG_LINK_DOWN
528308.434 CMAC_LOG_LINK_UP
