- Hewlett-Packard Switch User Manual
Table Of Contents
- HP ProCurve 2520 Switches Management and Configuration Guide
- Front Cover
- Title Page
- Copyright, Notices, & Publication Data
- Contents
- Feature Index
- 1.Getting Started
- 2.Selecting a Management Interface
- 3.Using the Menu Interface
- 4.Using the Command Line Interface (CLI)
- 5.Using the ProCurve Web Browser Interface
- 6.Switch Memory and Configuration
- 7.Interface Access and System Information
- 8.Configuring IP Addressing
- 9.Time Protocols
- 10.Port Status and Configuration
- Contents
- Overview
- Viewing Port Status and Configuring Port Parameters
- Menu: Port Status and Configuration
- CLI: Viewing Port Status and Configuring Port Parameters
- Customizing the Show Interfaces Command
- Viewing Port Utilization Statistics
- Viewing Transceiver Status
- Enabling or Disabling Ports and Configuring Port Mode
- Enabling or Disabling Flow Control
- Configuring a Broadcast Limit on the Switch
- Configuring ProCurve Auto-MDIX
- Web: Viewing Port Status and Configuring Port Parameters
- Using Friendly (Optional) Port Names
- 11.Power Over Ethernet (PoE) Operation
- 12.Port Trunking
- Contents
- Overview
- Port Trunk Features and Operation
- Trunk Configuration Methods
- Menu: Viewing and Configuring a Static Trunk Group
- CLI: Viewing and Configuring Port Trunk Groups
- Web: Viewing Existing Port Trunk Groups
- Trunk Group Operation Using LACP
- Trunk Group Operation Using the “Trunk” Option
- How the Switch Lists Trunk Data
- Outbound Traffic Distribution Across Trunked Links
- 13.Configuring for Network Management Applications
- Contents
- Using SNMP Tools To Manage the Switch
- LLDP (Link-Layer Discovery Protocol)
- Terminology
- General LLDP Operation
- Packet Boundaries in a Network Topology
- Configuration Options
- Options for Reading LLDP Information Collected by the Switch
- LLDP and LLDP-MED Standards Compatibility
- LLDP Operating Rules
- Configuring LLDP Operation
- LLDP-MED (Media-Endpoint-Discovery)
- Displaying Advertisement Data
- LLDP Operating Notes
- LLDP and CDP Data Management
- A.File Transfers
- B.Monitoring and Analyzing Switch Operation
- Contents
- Overview
- Status and Counters Data
- Menu Access To Status and Counters
- General System Information
- Task Monitor—Collecting Processor Data
- Switch Management Address Information
- Port Status
- Viewing Port and Trunk Group Statistics and Flow Control Status
- Viewing the Switch’s MAC Address Tables
- Spanning Tree Protocol (MSTP) Information
- Internet Group Management Protocol (IGMP) Status
- VLAN Information
- Web Browser Interface Status Information
- Interface Monitoring Features
- Locating a Device
- C.Troubleshooting
- Contents
- Overview
- Troubleshooting Approaches
- Browser or Telnet Access Problems
- Unusual Network Activity
- General Problems
- 802.1Q Prioritization Problems
- IGMP-Related Problems
- LACP-Related Problems
- Port-Based Access Control (802.1X)-Related Problems
- QoS-Related Problems
- Radius-Related Problems
- Spanning-Tree Protocol (MSTP) and Fast-Uplink Problems
- SSH-Related Problems
- TACACS-Related Problems
- TimeP, SNTP, or Gateway Problems
- VLAN-Related Problems
- Fan Failure
- Using the Event Log for Troubleshooting Switch Problems
- Debug/Syslog Operation
- Debug/Syslog Messaging
- Debug/Syslog Destination Devices
- Debug/Syslog Configuration Commands
- Configuring Debug/Syslog Operation
- Debug Command
- Logging Command
- Adding a Description for a Syslog Server
- Adding a Priority Description
- Configuring the Severity Level for Event Log Messages Sent to a Syslog Server
- Operating Notes for Debug and Syslog
- Diagnostic Tools
- Viewing Switch Configuration and Operation
- Restoring the Factory-Default Configuration
- Restoring a Flash Image
- DNS Resolver
- D.MAC Address Management
- E.Daylight Savings Time on ProCurve Switches
- F.Power-Saving Features
- Index
- Notices & Publication Data

Troubleshooting
Using the Event Log for Troubleshooting Switch Problems
CLI: Turning Event Numbering On
Syntax: [no] log-numbers
Turns event numbering on and off
Using Log Throttling to Reduce Duplicate
Event Log and SNMP Messages
A recurring event can generate a series of duplicate Event Log messages and
SNMP traps in a relatively short time. As a result, the Event Log and any
configured SNMP trap receivers may be flooded with excessive, exactly
identical messages. To help reduce this problem, the switch uses log throttle
periods to regulate (throttle) duplicate messages for recurring events, and
maintains a counter to record how many times it detects duplicates of a
particular event since the last system reboot.
When the first instance of a particular event or condition generates a message,
the switch initiates a log throttle period that applies to all recurrences of that
event. If the logged event recurs during the log throttle period, the switch
increments the counter initiated by the first instance of the event, but does
not generate a new message.
If the logged event repeats again after the log throttle period expires, the
switch generates a duplicate of the first message, increments the counter, and
starts a new log throttle period during which any additional instances of the
event are counted, but not logged. Thus, for a particular recurring event, the
switch displays only one message in the Event Log for each log throttle period
in which the event reoccurs. Also, each logged instance of the event message
includes counter data showing how many times the event has occurred since
the last reboot. The switch manages messages to SNMP trap receivers in the
same way.
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