debug cable-modem mac
Configuring the Cisco uBR900 Series Cable Access Routers 127
debug cable-modem mac
To troubleshoot the CiscouBR900 series MAC layer, use the debug cable-modem mac command
in privileged EXEC mode. To turn the debugging messages off, use the no form of this command.
[no] debug cable-modem mac {log [verbose] | messages}
Syntax Description
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Of all the available debug cable modem commands, the most useful is debug cable-modem mac
log.
MAC log messages are written to a circular log file even when debugging is not turned on. These
messages include timestamps, events, and information pertinent to these events. Enter the debug
cable-modem mac log command to view MAC log messages. If you want to view this information
without entering debug mode, enter the show controllers cable-modem number mac log command.
The same information is displayed by both commands.
If the Cisco uBR900 series interface fails to come up or resets periodically, the MAC log will show
what happened. For example, if an address is not obtained from the DHCP server, an error is logged,
initialization starts over, and the Cisco uBR900 series scans for a downstream frequency. The debug
cable-modem mac log command displays the log from the oldest to the newest entry.
After initial ranging is successful (dhcp_state has been reached), further RNG-REQ/RNG-RSP
messages and watchdog timer entries are suppressed from output unless the verbose keyword is
used. Note that CMAC_LOG_WATCHDOG_TIMER entries while in the maintenance_state are normal when
using the verbose keyword.
log Realtime MAC log display.
verbose (Optional) Displays periodic MAC layer events, such as ranging.
messages MAC layer management messages.
Release Modification
11.3 NA This command was introduced.