Configuring Headend Broadband Access Router Features
Troubleshooting Using Cable Flap Lists
MC-604
Cisco IOS Multiservice Applications Configuration Guide
Verifying Cable Flap List Aging
To verify that cable flap list aging is set, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr CableIF Ins Hit Miss CRC P-Adj Flap Time
0010.7b6b.5d1d C3/0 U0 0 688 169 0 0 3 Nov 5 12:28:50
0010.7b6b.5e15 C3/0 U0 1 707 185 0 0 5 Nov 5 12:29:52
0010.7b6b.5e27 C3/0 U0 1 707 198 0 0 5 Nov 5 12:29:55
0010.7b6b.5d29 C3/0 U0 1 709 205 0 0 5 Nov 5 12:29:52
0010.7b6b.5e2b C3/0 U0 1 710 204 0 0 7 Nov 5 12:30:16
Setting Cable Flap List Insertion Time
You can set the cable flap list insertion time. When a cable modem makes an insertion request more
frequently than the amount of insertion time defined by this command, the cable modem is placed in the
flap list for activity recording. The valid range is from 60 to 86400 seconds.
To set the cable flap list insertion time, use the following command in global configuration mode:
Verifying Cable Flap List Insertion Time
To verify cable flap list insertion time, enter the show cable flap list command:
CMTS01# show cable flap list
Mac Addr CableIF Ins Hit Miss CRC P-Adj Flap Time
0010.7b6b.5d1d C3/0 U0 0 688 169 0 0 3 Nov 5 12:28:50
0010.7b6b.5e15 C3/0 U0 1 707 185 0 0 5 Nov 5 12:29:52
0010.7b6b.5e27 C3/0 U0 1 707 198 0 0 5 Nov 5 12:29:55
0010.7b6b.5d29 C3/0 U0 1 709 205 0 0 5 Nov 5 12:29:52
0010.7b6b.5e2b C3/0 U0 1 710 204 0 0 7 Nov 5 12:30:16
Setting Cable Flap List Power Adjustment Threshold
You can specify the power adjustment threshold that will cause a flap list event to be recorded. When
the power adjustment of a cable modem meets or exceeds the threshold, the cable modem is placed in
the flap list. The valid range is from 1 to 10 dBmV.
Note A power adjustment threshold of less than 2 dBmV might cause excessive flap list event
recording. We recommend setting this threshold value to 3 dBmV or higher.
To set the power adjustment threshold for flap list events, use the following command in global
configuration mode:
Command Purpose
CMTS01(config)# cable flap-list insertion-time seconds
Specifies the insertion time in seconds. Any cable modem
that makes an insertion request more frequently than this
period of time is placed in the flap list.
