- 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)
TLV (Type-Length-Value): A data unit that includes a data type field, a data
unit length field (in bytes), and a field containing the actual data the unit is
designed to carry (as an alphanumeric string, a bitmap, or a subgroup of
information). Some TLVs include subelements that occur as separate data
points in displays of information maintained by the switch for LLDP
advertisements. (That is, some TLVs include multiple data points or
subelements.)
General LLDP Operation
An LLDP packet contains data about the transmitting switch and port. The
switch advertises itself to adjacent (neighbor) devices by transmitting LLDP
data packets out all ports on which outbound LLDP is enabled, and reading
LLDP advertisements from neighbor devices on ports that are inbound LLDP-
enabled. (LLDP is a one-way protocol and does not include any
acknowledgement mechanism.) An LLDP-enabled port receiving LLDP
packets inbound from neighbor devices stores the packet data in a Neighbor
database (MIB).
LLDP-MED
This capability is an extension to LLDP and is available on the switches
covered in this guide. Refer to “LLDP-MED (Media-Endpoint-Discovery)” on
page 13-53.
Packet Boundaries in a Network Topology
■ Where multiple LLDP devices are directly connected, an outbound LLDP
packet travels only to the next LLDP device. An LLDP-capable device does
not forward LLDP packets to any other devices, regardless of whether
they are LLDP-enabled.
■ An intervening hub or repeater forwards the LLDP packets it receives in
the same manner as any other multicast packets it receives. Thus, two
LLDP switches joined by a hub or repeater handle LLDP traffic in the same
way that they would if directly connected.
■ Any intervening 802.1D device or Layer-3 device that is either LLDP-
unaware or has disabled LLDP operation drops the packet.
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