Cisco Broadband Cable Command Reference Guide

ping docsis
ping docsis
Syntax Description
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Cisco Broadband Cable Command Reference Guide
Chapter 5 Cable CPE Commands
To determine whether a specific CM is reachable from the CMTS at the DOCSIS MAC layer, use the
ping docsis command in privileged EXEC mode.
Cisco uBR904, uBR905, uBR924, uBR925 cable access routers, Cisco CVA122 Cable Voice Adapter
ping docsis {mac-addr | ip-addr} [count] [verbose]
Defaults If no count is specified, five DOCSIS ping packets are sent.
Command Modes Privileged EXEC
Command History
mac-addr Specifies the 48-bit hardware (MAC) address of the CM.
ip-addr Specifies the IP address of the CM.
count Specifies the number of ping packets to be sent.
verbose Specifies verbose mode for the output, giving additional details about the packets
transmitted and received.
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.
Usage Guidelines The DOCSIS ping is a unique Cisco technology that allows a cable operator to quickly diagnose the
health of a channel between the CMTS and any particular DOCSIS cable CPE device. The DOCSIS ping
is similar in concept to the IP ping but uses the lower MAC layer instead of the datalink or transport
layers. Using the MAC layer has two major advantages:
A DOCSIS ping uses only 1/64 of the bandwidth of an IP ping.
A DOCSIS ping can be used with CMs that have not yet acquired an IP address. This allows cable
operators to “ping” CMs that weren't able to complete registration or that were improperly
configured at the IP layer.
In addition to providing connectivity information, the ping docsis command provides a real-time view
and plot of requested power adjustments, frequency, timing offset adjustments, and a measure of optimal
CMTS reception power.
If a CM responds to the ping docsis command, but does not respond to an IP ping, the problem could be
one of the following:
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