- 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

Time Protocols
Selecting a Time Synchronization Protocol or Turning Off Time Protocol Operation
Note To use Broadcast mode, the switch and the SNTP server must be in the same
subnet.
■ Unicast Mode: The switch requests a time update from the config-
ured SNTP server. (You can configure one server using the menu
interface, or up to three servers using the CLI sntp server command.)
This option provides increased security over the Broadcast mode by
specifying which time server to use instead of using the first one
detected through a broadcast.
Selecting a Time Synchronization
Protocol or Turning Off Time Protocol
Operation
General Steps for Running a Time Protocol on the Switch:
1. Select the time synchronization protocol: SNTP or TimeP (the default).
2. Enable the protocol. The choices are:
• SNTP: Broadcast or Unicast
• TimeP: DHCP or Manual
3. Configure the remaining parameters for the time protocol you selected.
The switch retains the parameter settings for both time protocols even if
you change from one protocol to the other. Thus, if you select a time
protocol, the switch uses the parameters you last configured for the
selected protocol.
Note that simply selecting a time synchronization protocol does not enable
that protocol on the switch unless you also enable the protocol itself (step 2,
above). For example, in the factory-default configuration, TimeP is the
selected time synchronization method. However, because TimeP is disabled
in the factory-default configuration, no time synchronization protocol is
running.
Disabling Time Synchronization
You can use either of the following methods to disable time synchronization
without changing the Timep or SNTP configuration:
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