3-87
Cisco Broadband Cable Command Reference Guide
OL-1581-08
Chapter 3 Cisco CMTS Show Commands
show cable modem flap
Note
Also see the information about this command’s behavior in a Hot Standby Connection-to-Connection
Protocol (HCCP) configuration, see the
“Operation with Hot Standby Connection-to-Connection
Protocol (HCCP) Configuration” section on page 3-54
.
Examples
The following example shows sample output for the
show cable modem flap
command for all cable
modems on a specific cable interface:
Router#
show cable modem c8/1/0 flap
MAC Address I/F Ins Hit Miss CRC P-Adj Flap Time
0050.7366.1243 C8/1/0/U1 6 29770 79 0 0 11 Apr 28 13:08:06
0002.b970.0027 C8/1/0/U4 6 29737 109 0 1 14 Apr 28 13:08:44
0006.5314.858d C8/1/0/U4 2 29635 41 0 0 4 Apr 28 13:09:21
Router#
The following example shows sample output for the
show cable modem flap
command for a particular
CM:
Router#
show cable modem 0010.7bb3.fcd1 flap
MAC Address I/F Ins Hit Miss CRC P-Adj Flap Time
0010.7bb3.fcd1 C5/0/U5 0 36278 92 0 369 372 Jun 1 13:05:23
Router#
Table 3-22
describes the fields shown in the
show cable modem flap
displays:
Table 3-22 Descriptions for the show cable modem flap Fields
Field
Description
MAC Address
The MAC address for the CM.
I/F
The cable interface line card, including upstream, for this CM.
Ins
The number of times the CM comes up and inserts itself into the network. It
can indicate intermittent downstream sync loss or DHCP or modem
registration problems.
Hit
The number of times the CM responds to MAC layer keepalive messages.
(The minimum hit rate is once per 30 seconds. It can indicate intermittent
upstream, laser clipping, or common-path distortion.
Miss
The number of times the CM misses the MAC layer keepalive message. An 8
percent miss rate is normal for the Cisco cable interface line cards. It can
indicate intermittent upstream, laser clipping, or common-path distortion.
CRC
The number of cyclic redundancy check (CRC) errors from this CM. It can
indicate intermittent upstream, laser clipping, or common-path distortion.
P-Adj
The number of times the headend instructed the CM to adjust transmit (TX)
power more than 3 dB. It can indicate amplifier degradation, poor
connections, or thermal sensitivity.
Flap
The sum of P-Adj and Ins values. CMs with high flap counts have high SIDs
and might not register.
Time
The most recent time that the CM dropped the connection.