- 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

Configuring for Network Management Applications
LLDP (Link-Layer Discovery Protocol)
Protocol State Packet
Generation
Inbound Data Management Inbound Packet Forwarding
CDP Enabled
1
n/a Store inbound CDP data. No forwarding of inbound
CDP packets.
CDP Disabled n/a No storage of CDP data from Floods inbound CDP packets
neighbor devices. from connected devices to
outbound ports.
LLDP Enabled
1
Generates and Store inbound LLDP data. No forwarding of inbound
transmits LLDP packets.
LLDP packets
out all ports on
the switch.
LLDP Disabled No packet No storage of LLDP data No forwarding of inbound
generation. from neighbor devices. LLDP packets.
1
Both CDP data collection and LLDP transmit/receive are enabled in the default configuration.
If a switch receives CDP packets and LLDP packets from the same neighbor device on the
same port, it stores and displays the two types of information separately if the chassis and
port ID information in the two types of advertisements is different. In this case, if you want
to use only one type of data from a neighbor sending both types, disable the unwanted
protocol on either the neighbor device or on the switch. However, if the chassis and port ID
information in the two types of advertisements is the same, the LLDP information overwrites
the CDP data for the same neighbor device on the same port.
CDP Operation and Commands
By default the switches covered in this guide have CDP enabled on each port.
This is a read-only capability, meaning that the switch can receive and store
information about adjacent CDP devices but does not generate CDP packets.
When a CDP-enabled switch receives a CDP packet from another CDP device,
it enters that device’s data in the CDP Neighbors table, along with the port
number where the data was received (and does not forward the packet). The
switch also periodically purges the table of any entries that have expired. (The
hold time for any data entry in the switch’s CDP Neighbors table is configured
in the device transmitting the CDP packet, and cannot be controlled in the
switch receiving the packet.) A switch reviews the list of CDP neighbor entries
every three seconds, and purges any expired entries.
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