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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
clear cable modem reset
Usage Guidelines
This command instructs the Cisco CMTS to stop sending DOCSIS station maintenance messages to one
or more CMs, which effectively terminates the link to those CMs. A CM responds to this by resetting
itself. Depending on when the CM received the last station maintenance message, it can take up to 30
seconds before the CM detects the missing station maintenance messages and resets itself.
In some circumstances, the customer premises equipment (CPE) devices behind a CM stops receiving
traffic after the CM is reset. This is because the CMTS still has the CPE device listed in its address tables,
but the CM does not after being reset, so the traffic passes through the CMTS but is dropped by the CM.
To resolve this situation, the CPE device should simply send some type of traffic to the CM, such as a
ping packet. (You can also resolve this situation by using the
clear arp-cache
command on the
Cisco CMTS router to clear the router’s address table, but this is not recommended, because it
temporarily interrupts all traffic on the router.)
Note
The
clear cable modem all reset
command can result in the CPU utilization temporarily reaching
100 percent for a couple of minutes, as the CPU processes the command for all CMs. The CPU
utilization will return to normal within a couple of minutes.
Caution
The
clear cable modem all reset
command should normally be used only on a test or lab network. If
used on a large network, it could impact service for a significant period of time, as it would force all
CMs to simultaneously reset and reregister with the Cisco CMTS.
Tip
You can also specify the MAC address or IP address for a CPE device or host, and the Cisco CMTS resets
the CM that is associated with that CPE device in its internal database.
Examples
The following example shows how to reset the CM at 172.23.45.67:
Router#
clear cable modem 172.23.45.67 reset
Router#
The following example shows how to reset all CMs that have a OUI that has been defined as having the
vendor name of Cisco using the
cable modem vendor
command:
Router#
clear cable modem oui Cisco reset
Router#
The following example shows how to reset all CMs that are currently in one of the reject states:
Router#
clear cable modem reject reset
Router#
Related Commands
12.2(11)BC3 The
all
option was removed from the Release 12.2 BC train, and replaced
with the
interface
option.
12.2(15)BC1
The cable interface was made an optional keyword for this command.
Release
Modification