Cisco SR2016T-NA Reference Manual page 479

Chapter 2 Cisco CMTS Configuration Commands
ping docsis
Examples The following example shows a default ping docsis command that sends five packets to the CM with the
MAC address of 00d0.ba77.7595, with a response being received for each:
Router# ping docsis 00d0.ba77.7595
Queueing 5 MAC-layer station maintenance intervals, timeout is 25 msec:
!!!!!
Success rate is 100 percent (5/5)
Router#
The following example shows the verbose output for the same command:
Router# ping docsis 00d0.ba77.7595 verbose
Queueing 5 MAC-layer station maintenance intervals, timeout is 25 msec:
Reply from 00d0.ba77.7595: 2 ms, tadj=-1, padj=0.50, fadj=0
Reply from 00d0.ba77.7595: 2 ms, tadj=-1, padj=0.50, fadj=0
Reply from 00d0.ba77.7595: 2 ms, tadj=-1, padj=0.50, fadj=0
Reply from 00d0.ba77.7595: 98 ms, tadj=-1, padj=0.25, fadj=0
Reply from 00d0.ba77.7595: 2 ms, tadj=-1, padj=0.25, fadj=0
Success rate is 100 percent (5/5)
Router#
The following example shows that the CM at 192.168.100.10 is connected to the network and is
operational, but that one ping packet was lost and that several power adjustments were made during the
ping process:
router# ping docsis 192.168.100.10
Queueing 100 MAC-layer station maintenance intervals, timeout is 25 msec:
!!!!!a!!!!!!!a!a!!!!!!!!!!!!!!!!!!!!!aa!!!!!!!!!!a!!!a!a!!!aa!!!!!!.!!a!!!a!
a!a!!!!!!!!aa!!!!!!!aa!a
Success rate is 99 percent (99/100)
A CM that displays output such as that above (a higher percentage of successful pings but with a number
of power-adjustment readings) is most likely experiencing a problem that is not bad enough to force the
modem offline but that should be addressed.
If this problem is consistent for just a small number of CMs on an upstream receiver (such as a fiber node
within a combining group), then the problem is likely related to in-home wiring at those modem
locations. It could also be due to a cable TV network element that is on the same HFC segment.
If the problem occurs for all CMs on a single fiber node, then changing the upstream frequency or
reducing the number of homes passed per combining group might improve conditions. If this does not
help the situation, the problem could be due to a faulty cable drop, dirty optical connector on the node,
or other physical plant problem.
The ping docsis command cannot be used with a CM that has not yet registered with the CMTS. The
following example shows the responses for a CM that has not yet registered with the CMTS.
router# ping docsis 192.168.100.111
Cable modem with IP address 192.168.100.111 not registered.
Please try using MAC address instead.
router# ping docsis 0123.4567.89ab
Cable modem with MAC address 0123.4567.89ab not registered.
router#
Cisco Broadband Cable Command Reference Guide
2-467
OL-1581-08