Setting Cable Flap List Miss Threshold | Cisco Systems uBR7200

Configuring Headend Broadband Access Router Features

Troubleshooting Using Cable Flap Lists

Command	Purpose

CMTS01(config)# cable flap-list power-adjust threshold dbmv	Specifies the minimum power adjustment that will
	constitute a flap list event.

Verifying Cable Flap List Power Adjustment Threshold

To verify the cable flap list power adjustment threshold, 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 Miss Threshold

You can specify the miss threshold for recording a flap list event. A miss is the number of times a cable modem does not acknowledge a MAC-layer keepalive message from a cable modem card. An

8 percent miss rate is normal for the Cisco cable modem cards. When the number of misses exceeds the threshold, the cable modem is placed in the flap list.

Note A high miss rate can indicate intermittent upstream problems, fiber laser clipping, or common-path distortion.

To set the miss threshold for recording a flap list event, use the following command in global configuration mode:

Command	Purpose

CMTS01(config)# cable flap-list miss-threshold misses	Specifies the number of MAC-layer keepalive
	misses that will result in the cable modems being
	place in the flap list.

Verifying Cable Flap List Miss Threshold

To verify the cable flap list miss threshold, 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

Cisco IOS Multiservice Applications Configuration Guide

MC-605

Image 87

Cisco Systems uBR7200 Setting Cable Flap List Miss Threshold, Verifying Cable Flap List Power Adjustment Threshold, MC-605

Contents

MC-519 Configuring Headend Broadband Access Router Features MC-520 Headend Overview Topology of a Typical Broadband Network Voice over IP Services MC-523 Telco Return TOD MC-524 MC-525 QoS FeaturesService Class Profiles Multiple Service IDs TAG/NetFlow Switching QoS Profile EnforcementMC-526 Tag Switching Netflow SwitchingMC-527 Committed Access Rate CAR Security FeaturesWeighted Random Early Detection Weighted Fair Queueing MC-529 Cable Modem and Multicast Authentication Using RadiusDocsis Baseline Privacy Upstream Address Verification MC-530 Traffic Shaping FeaturesOperations and Provisioning Features Dynamic Ranging CPE Limitation Downstream Channel ID ConfigurationBurst Profile Configuration Downstream Frequency Override Spectrum Management MC-533 Headend Broadband Access Router Configuration Prerequisites MC-534 Headend Broadband Access Router Configuration Tasks Activating the Downstream Carrier Configuring the Downstream Cable InterfaceCMTS01# configure terminal CMTS01config# interface cable 6/0 MC-536 Setting the Downstream Center FrequencyTroubleshooting Tips Verifying the Downstream Carrier CMTS01config-if#cable downstream frequency Verifying the Downstream Center FrequencyMC-537 MC-538 Setting the Downstream Channel IDSetting the Downstream Mpeg Framing Format Annex B Verifying the Downstream Channel ID MC-539 Setting the Downstream ModulationVerifying the Downstream Mpeg Framing Format Verifying the Downstream Modulation MC-540 Setting the Downstream Interleave DepthCMTS01config-if#cable downstream interleave-depth Verifying the Downstream Interleave Depth Setting the Downstream Helper Address Verifying the Downstream Helper AddressMC-541 MC-542 Setting Downstream Rate Limiting Configuring the Upstream Cable Interface Verifying Downstream Rate LimitingMC-543 MC-544 Setting the Upstream Frequency Verifying the Upstream Frequency MC-545CMTS01# show controllers cable 6/0 u0 Channel-width width Setting the Upstream Channel WidthVerifying Upstream Channel Width MC-546 MC-547 Setting the Upstream Input Power Level MC-548 Verifying the Upstream Input Power LevelActivating Upstream Admission Control Verifying Upstream Admission Control MC-549 Activating Upstream FEC MC-550 Router# more systemrunning-configSpecifying Upstream Minislot Size Verifying Upstream FEC Activating the Upstream Scrambler Verifying Upstream Minislot SizeMC-551 MC-552 CMTS01config-if#cable upstream usport scramblerCMTS01# more systemrunning-config Verifying the Upstream Scrambler MC-553 Activating Upstream Differential EncodingActivating Upstream Rate Limiting Verifying Upstream Differential Encoding CMTS01config-if#no cable upstream usport rate-limit Verifying Upstream Rate LimitingMC-554 Activating Upstream Frequency Adjustment Frequency-adjust averaging percentageMC-555 Activating Upstream Power Adjustment Verifying Upstream Frequency AdjustmentMC-556 Continue seconds Activating Upstream Timing AdjustmentVerifying Upstream Power Adjustment MC-557 Verifying Upstream Timing Adjustment Activating the Upstream PortsMC-558 Setting Upstream Backoff Values Verifying the Upstream PortsMC-559 Data-backoff automatic CMTS01config-if#cable upstream usport rangeMC-560 Data-backoff start end Configuring and Activating Baseline Privacy Verifying Upstream Data Backoff AutomaticMC-561 Configuring KEK Privacy CMTS01config-if#cable privacy kek grace-timeMC-562 MC-563 Configuring TEK PrivacyVerifying KEK Privacy Verifying TEK Privacy MC-564 Configuring and Activating Frequency AgilityActivating Baseline Privacy Verifying Baseline Privacy MC-565 Combiner Groups MC-566 Frequency Management Policy MC-567 Determining the Upstream Ports Assigned to a Combiner Group MC-568 Configuring and Activating Spectrum GroupsCreating Spectrum Groups Verifying Spectrum Groups MC-569 Command Purpose MC-570 Verifying Spectrum Group Configuration Verifying Frequency HoppingMC-571 MC-572 Configuring Spectrum Group Characteristics Threshold percent Verifying Spectrum Group CharacteristicsCMTS01config# cable spectrum-group groupnum hop MC-573 Verifying Spectrum Group and Upstream Port Assignments Activating IP Address Resolution ProtocolAssigning the Spectrum Group and the Upstream Ports Activating Cable ARP Requests Activating Host-to-Host Communication Proxy ARP Verifying ARP RequestsMC-575 Verifying Cable Proxy ARP Requests Configuring Dhcp OptionsActivating Cable Proxy ARP Requests Activating Cable Relay Agent Activating Dhcp giaddr Verifying Dhcp giaddr ActivationMC-577 Verifying ToD Service Setting Service OptionsSetting Optional IP Parameters Configuring ToD Service MC-579 Activating IP Multicast EchoActivating IP Broadcast Echo Verifying IP Multicast Echo MC-580 Configuring Cable ProfilesConfiguring Cable Modulation Profiles Verifying IP Broadcast Echo MC-581 Number profile Configuring QoS Profiles Verifying Cable Modulation ProfilesMC-582 MC-583 Verifying QoS Profiles MC-584 Setting QoS PermissionEnforcing a QoS Profile Assignment Verifying QoS Permission Managing Cable Modems on the HFC Network Verifying a QoS Profile AssignmentMC-585 Verifying Sync Message Interval Configuring Sync Message IntervalConfiguring Telco Return Activating Cable Modem Authentication Verifying Cable Modem Authentication Activating Cable Modem Upstream Address VerificationMC-587 MC-588 CMTS01config-if#cable source-verify dhcpActivating Cable Modem Insertion Interval Verifying Cable Modem Upstream Address Verification CMTS01config-if#cable insertion-interval automatic Verifying Cable Modem Insertion IntervalMC-589 Configuring Cable Modem Registration Timeout Verifying the Maximum Number of HostsMC-590 Clearing and Resetting Cable Modems Verifying Registration TimeoutMC-591 Verifying Cable Modem Clearing and Resetting Clearing Cable Modem CountersMC-592 MC-593 Using Ping DocsisVerifying that Cable Modem Counters are Cleared Verifying Ping Docsis MC-594 Spectrum Management Configuration Example MC-595 Virtual Private Network Configuration Example MC-596 MC-597 Ip http server Ip http authentication local No cdp run MC-598 VoIP Configuration Example Ip subnet-zero No ip domain-lookup MC-599 MC-600 Telco Return Configuration Example MC-601 Cable telco-return enable Cable Reg QoS Profile Enforcement Configuration ExampleCable Modem all reset MC-602 MC-603 Troubleshooting Using Cable Flap ListsSetting Cable Flap List Aging CMTS01config# cable flap-list aging days Verifying Cable Flap List Insertion Time Setting Cable Flap List Insertion TimeSetting Cable Flap List Power Adjustment Threshold Verifying Cable Flap List Aging Verifying Cable Flap List Miss Threshold Setting Cable Flap List Miss ThresholdVerifying Cable Flap List Power Adjustment Threshold CMTS01config# cable flap-list miss-threshold misses MC-606 Setting Cable Flap List SizeClearing Cable Flap List Verifying Cable Flap List Size