Installation guide

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Cisco uBR7100 Series Universal Broadband Router Software Configuration Guide
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Chapter 5 Troubleshooting the System
Troubleshooting Cable Flap Lists
• When the cable modem re-registers more frequently than the user-specified insertion time.
• When intermittent keepalive messages are detected between the CMTS and the cable modem.
• When the cable modem’s upstream transmit power is adjusted beyond the user-specified power
threshold.
Displaying the Flap List
The flap list can be queried either using the standard Simple Network Management (SNMP) API or the
CLI. Using any third
party SNMP Management Information Base (MIB) browser, you can query the
ccsFlapTable in the CISCO-CABLE-SPECTRUM-MIB, a proprietary extension to the DOCSIS MIBs.
Using the show cable flap list command, the flap list statistics are accessed. Refer to the following
example. Each of the columns in the display are described in Table 5-8:
MAC ID___ CableIF Ins _Hit__ Miss CRC P-Adj Flap ___Time____
0010.7b6b.60ad C1/0 U0 0 14386 1390 1 38 41 Nov 24 21:34:24
0010.7b6b.65a3 C1/0 U0 0 14503 1264 1 33 37 Nov 24 21:28:09
0010.7b6b.6b9d C1/0 U0 0 14060 1726 3 40 43 Nov 24 21:18:36
Table 5-8 Flap List Statistics Description
Statistic Description
MAC ID MAC-layer address of a cable modem. The first six digits indicate the
vendor ID of the cable modem manufacturer, followed by six digits
indicating a unique host address. Each cable modem's MAC address is
unique.
Cable IF The physical upstream interface on the Cisco uBR7100 series CMTS. It
denotes the cable modem card slot number, the downstream port number on
the RF line card and the upstream port number on the same cable modem
card. The flap list data can be sorted based on the upstream port number
which is useful when isolating reverse path problems unique to certain
combining groups.