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Cisco Broadband Cable Command Reference Guide
OL-1581-07
Chapter 6 Cable CPE Commands
debug cable-modem mac log
debug cable-modem mac log
To display comprehensive debugging messages for the cable interface MAC layer, use the
debug
cable-modem mac log
command in privileged EXEC mode. To turn off debugging for the MAC layer,
use the
no
form of this command.
Cisco uBR904, uBR905, uBR924, uBR925 cable access routers, Cisco CVA122 Cable Voice Adapter
debug cable-modem mac log
[
verbose
]
no debug cable-modem mac log
[
verbose
]
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The
debug cable-modem mac log
command is one of the most useful debugging tools because
MAC-layer 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, use the
show controllers cable-modem
number
mac log
command. The
same information is displayed by both commands.
Tip
The
debug cable-modem mac log
command displays details about the MAC-layer processes. In
particular, this command displays the details of the CM’s registration and initialization process.
If the router 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 CM scans for a downstream frequency. The
debug cable-modem mac log
command displays
the log from oldest entry to 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.
verbose
(Optional) Displays periodic MAC layer events, such as ranging.
Release
Modification
11.3(4)NA
This command was introduced for the Cisco uBR904 cable access router.
12.0(4)XI1
Support was added for the Cisco uBR924 cable access router.
12.1(3)XL
Support was added for the Cisco uBR905 cable access router.
12.1(5)XU1
Support was added for the Cisco CVA122 Cable Voice Adapter.
12.2(2)XA
Support was added for the Cisco uBR925 cable access router.