Cisco Systems UBR900 User Manual

Cisco IOS Release 12.0(7)T

To display detailed MAC-layer information for a Cisco uBR900 series, use the show controllers 
cable-modem mac command in privileged EXEC mode.

show controllers cable-modem number mac [errors | hardware | log | resets | state]

Syntax Description

Defaults

No default behavior or values.

Command Modes

Privileged EXEC

Command History

Usage Guidelines

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. Use the show 
controllers cable-modem mac log command to view MAC log messages. 

If the Cisco uBR900 series interface fails to come up or resets periodically, the MAC log will capture 
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 most useful keywords for troubleshooting a Cisco uBR900 series are log, errors, and resets. 
See Example 1, Example 2, and Example 3.

Controller number inside the Cisco uBR900 series.

(Optional) Displays a log of the error events that are reported to SNMP. This keyword 
enables you to look at the error events without accessing a MIB.

(Optional) Displays all MAC hardware registers.

(Optional) Displays a history of MAC log messages, up to 1023 entries. This is the same 
output that is displayed when using the debug cable-modem mac log command.

(Optional) Extracts all of the reset causes out of the MAC log file and summarizes them 
in a mini report. 

(Optional) Displays a summary of the MAC state.

11.3 NA

This command was introduced.