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Cisco uBR7200 Series Universal Broadband Router Software Configuration Guide
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Chapter4 Troubleshooting the System Using Cable Interface Debug Commands

Verify the Ping

The ping docsis command returns a verification from a cable modem that is pinged:
Queueing 5 MAC-layer station maintenance intervals, timeout is 25 msec:
!!!!!
Success rate is 100 percent (5/5)
Tips If you are having trouble, make sure you are using a valid MAC or IP address for the
cable modem you want to ping.
Using Cable Interface Debug Commands
To troubleshoot cable interfaces, use the following debug commands in enable (privileged EXEC)
mode.
Caution The following commands can generate large amounts of output as the number of
cable modems grows.On heavily loaded systems with thousands of cable modems, these
commands can dramatically affect router performance.

Debug Cable ARP Requests

This command activates debugging of arp requests on the cable interfaces. When this command is
activated, all cable arp request messages are displayed on the CiscouBR7200 series console. The
format for the command follows:
CMTS01# debug cable arp
To deactivate debugging of arp requests, use the following command:
CMTS01# no debug cable arp
Table4-32 Instructions to Use Debug Command
Command Purpose
CMTS01# debug cable ? View all debug cable commands that are available.
CMTS01# undebug all Turn off all debugging information to the console
and choose a more selective debug command.
Note Refer to the debug commands
that follow.