Time Protocols
General steps for running a time protocol on the switch
TimeP time synchronization
SNTP time synchronization
Selecting a time synchronization protocol
Disabling time synchronization
SNTP: Selecting and configuring
Viewing and configuring SNTP (Menu)
Viewing and configuring SNTP (CLI)
Configuring (enabling or disabling) the SNTP mode
SNTP client authentication
Configuring the key-identifier, authentication mode, and key-value (CLI)
Configuring a trusted key
Associating a key with an SNTP server (CLI)
Enabling SNTP client authentication
Configuring unicast and broadcast mode for authentication
Viewing SNTP authentication configuration information (CLI)
Saving configuration files and the include-credentials command
TimeP: Selecting and configuring
Viewing, enabling, and modifying the TimeP protocol (Menu)
Viewing the current TimeP configuration (CLI)
Configuring (enabling or disabling) the TimeP mode
SNTP unicast time polling with multiple SNTP servers
Displaying all SNTP server addresses configured on the switch (CLI)
Adding and deleting SNTP server addresses
Adding addresses
Deleting addresses
Operating with multiple SNTP server addresses configured (Menu)
SNTP messages in the Event Log
Monitoring resources
Displaying current resource usage
Viewing information on resource usage
Policy enforcement engine
Usage notes for show resources output
When insufficient resources are available
Port Status and Configuration
Viewing port status and configuring port parameters
Connecting transceivers to fixed-configuration devices
Viewing port configuration (Menu)
Configuring ports (Menu)
Viewing port status and configuration (CLI)
Dynamically updating the show interfaces command (CLI/Menu)
Customizing the show interfaces command (CLI)
Error messages associated with the show interfaces command
Viewing port utilization statistics (CLI)
Operating notes for viewing port utilization statistics
Viewing transceiver status (CLI)
Operating notes
Enabling or disabling ports and configuring port mode (CLI)
Enabling or disabling flow control (CLI)
Port shutdown with broadcast storm
Viewing broadcast storm
Configuring auto-MDIX
Manual override
Configuring auto-MDIX (CLI)
Using friendly (optional) port names
Configuring and operating rules for friendly port names
Configuring friendly port names (CLI)
Configuring a single port name (CLI)
Configuring the same name for multiple ports (CLI)
Displaying friendly port names with other port data (CLI)
Listing all ports or selected ports with their friendly port names (CLI)
Including friendly port names in per-port statistics listings (CLI)
Searching the configuration for ports with friendly port names (CLI)
Uni-directional link detection (UDLD)
Uplink failure detection
Power Over Ethernet (PoE/PoE+) Operation
Introduction to PoE
PoE terminology
PoE operation
Configuration options
PD support
Power priority operation
When is power allocation prioritized?
How is power allocation prioritized?
Configuring PoE operation
Disabling or re-enabling PoE port operation
Enabling support for pre-standard devices
Configuring the PoE port priority
Controlling PoE allocation
Manually configuring PoE power levels
Configuring PoE redundancy
Changing the threshold for generating a power notice
PoE/PoE+ allocation using LLDP information
LLDP with PoE
Enabling or disabling ports for allocating power using LLDP
Enabling PoE detection via LLDP TLV advertisement
LLDP with PoE+
PoE allocation
Viewing PoE when using LLDP information
Operating note
Viewing the global PoE power status of the switch
Viewing PoE status on all ports
Viewing the PoE status on specific ports
Using the HP 2920 Switch with an external power supply
Supported PSUs
Using the XPS for additional PoE power
Determining the maximum available PoE power
Operating rules
Using redundant (N+1) power
Providing non-PoE redundant power
Configuring the HP 2920 PoE switches to use the XPS
Enabling and disabling power from the XPS
Configuring auto-recovery
Restoring the default external power supply settings
Distributing power to specified ports
Example: of the power-share option
Example: of adding a switch
Example: of using the force option
Reducing allocated external power
Example: configurations
Non-PoE configuration
PoE configuration for full PoE power to one XPS port
PoE configuration for multiple switches
Viewing power information
Examples for show external-power-supply
Examples for show power-over-ethernet commands
Example: for show running-config command
Planning and implementing a PoE configuration
Power requirements
Assigning PoE ports to VLANs
Applying security features to PoE configurations
Assigning priority policies to PoE traffic
PoE Event Log messages
Port Trunking
Overview of port trunking
Port connections and configuration
Port trunk features and operation
Fault tolerance
Trunk configuration methods
Dynamic LACP trunk
Using keys to control dynamic LACP trunk configuration
Static trunk
Viewing and configuring a static trunk group (Menu)
Viewing and configuring port trunk groups (CLI)
Viewing static trunk type and group for all ports or for selected ports
Viewing static LACP and dynamic LACP trunk data
Dynamic LACP Standby Links
Configuring a static trunk or static LACP trunk group
Removing ports from a static trunk group
Enabling a dynamic LACP trunk group
Removing ports from a dynamic LACP trunk group
Viewing existing port trunk groups (WebAgent)
Trunk group operation using LACP
Default port operation
LACP notes and restrictions
802.1X (Port-based access control) configured on a port
Port securityconfigured on a port
Changing trunking methods
Static LACP trunks
Dynamic LACP trunks
VLANs and dynamic LACP
Blocked ports with older devices
Spanning Tree and IGMP
Half-duplex, different port speeds, or both not allowed in LACP trunks
Dynamic/static LACP interoperation
Trunk group operation using the "trunk" option
How the switch lists trunk data
Outbound traffic distribution across trunked links
Trunk load balancing using port layers
Enabling trunk load balancing
Port Traffic Controls
All traffic rate-limiting
Configuring in/out rate-limiting
Displaying the current rate-limit configuration
Operating notes for rate-limiting
ICMP rate-limiting
Guidelines for configuring ICMP rate-limiting
Configuring ICMP rate-limiting
Using both ICMP rate-limiting and all-traffic rate-limiting on the same interface
Viewing the current ICMP rate-limit configuration
Operating notes for ICMP rate-limiting
Notes on testing ICMP rate-limiting
ICMP rate-limiting trap and Event Log messages
Determining the switch port number used in ICMP port reset commands
Configuring inbound rate-limiting for broadcast and multicast traffic
Operating Notes
Configuring egress per-queue rate-limiting (2920, 3800, and 5400R switches only)
Configuration commands
Rate-limit queues out command
Show commands
show rate-limit queues
Guaranteed minimum bandwidth (GMB)
GMB operation
Impacts of QoS queue configuration on GMB operation
Configuring GMB for outbound traffic
Viewing the current GMB configuration
GMB operating notes
Impact of QoS queue configuration on GMB commands
Jumbo frames
Operating rules
Configuring jumbo frame operation
Viewing the current jumbo configuration
Enabling or disabling jumbo traffic on a VLAN
Configuring a maximum frame size
Configuring IP MTU
SNMP implementation
Displaying the maximum frame size
Operating notes for maximum frame size
Operating notes for jumbo traffic-handling
A VLAN is configured to allow jumbo frames, but one or more ports drops all inbound jumbo frames
A non-jumbo port is generating "Excessive undersize/giant frames" messages in the Event Log
Configuring for Network Management Applications
Using SNMP tools to manage the switch
SNMP management features
SNMPv1 and v2c access to the switch
SNMPv3 access to the switch
Enabling and disabling switch for access from SNMPv3 agents
Enabling or disabling restrictions to access from only SNMPv3 agents
Enabling or disabling restrictions from all non-SNMPv3 agents to read-only access
Viewing the operating status of SNMPv3
Viewing status of message reception of non-SNMPv3 messages
Viewing status of write messages of non-SNMPv3 messages
Enabling SNMPv3
SNMPv3 users
Group access levels
SNMPv3 communities
Viewing and configuring non-version-3 SNMP communities (Menu)
Listing community names and values (CLI)
SNMP notifications
Supported Notifications
General steps for configuring SNMP notifications
SNMPv1 and SNMPv2c Traps
SNMP trap receivers
SNMP trap when MAC address table changes
SNMPv2c informs
Configuring SNMPv3 notifications (CLI)
Network security notifications
Enabling Link-Change Traps (CLI)
Source IP address for SNMP notifications
Viewing SNMP notification configuration (CLI)
Configuring the MAC address count option
Displaying information about the mac-count-notify option
Advanced management: RMON
CLI-configured sFlow with multiple instances
Configuring sFlow (CLI)
Viewing sFlow Configuration and Status (CLI)
Configuring UDLD Verify before forwarding
UDLD time delay
UDLD configuration commands
Show commands
RMON generated when user changes UDLD mode
General LLDP operation
Packet boundaries in a network topology
LLDP operation configuration options
Enable or disable LLDP on the switch
Enable or disable LLDP-MED
Change the frequency of LLDP packet transmission to neighbor devices
Change the Time-To-Live for LLDP packets sent to neighbors
Transmit and receive mode
SNMP notification
Per-port (outbound) data options
Remote management address
Debug logging
Options for reading LLDP information collected by the switch
LLDP and LLDP-MED standards compatibility
LLDP operating rules
Port trunking
IP address advertisements
Spanning-tree blocking
802.1X blocking
Configuring LLDP operation
Displaying the global LLDP, port admin, and SNMP notification status (CLI)
Configuring Global LLDP Packet Controls
Configuring SNMP notification support
Configuring per-port transmit and receive modes (CLI)
Basic LLDP per-port advertisement content
Support for port speed and duplex advertisements
Port VLAN ID TLV support on LLDP
Configuring the VLAN ID TLV
Viewing the TLVs advertised
SNMP support
LLDP-MED (media-endpoint-discovery)
LLDP-MED endpoint support
LLDP-MED endpoint device classes
LLDP-MED operational support
LLDP-MED fast start control
Advertising device capability, network policy, PoE status and location data
Location data for LLDP-MED devices
Viewing switch information available for outbound advertisements
Displaying the current port speed and duplex configuration on a switch port
Viewing advertisements currently in the neighbors MIB
Displaying LLDP statistics
LLDP Operating Notes
Neighbor maximum
LLDP packet forwarding
One IP address advertisement per port
802.1Q VLAN Information
Effect of 802.1X Operation
Neighbor data can remain in the neighbor database after the neighbor is disconnected
Mandatory TLVs
LLDP and CDP data management
LLDP and CDP neighbor data
CDP operation and commands
Viewing the current CDP configuration of the switch
Viewing the current CDP neighbors table of the switch
Enabling and Disabling CDP Operation
Enabling or disabling CDP operation on individual ports
Configuring CDPv2 for voice transmission
Filtering CDP information
Configuring the switch to filter untagged traffic
Displaying the configuration
Filtering PVID mismatch log messages
DHCPv4 server
Introduction to DHCPv4
IP pools
DHCP options
BootP support
Authoritative server and support for DHCP inform packets
Authoritative pools
Authoritative dummy pools
Change in server behavior
DHCPv4 configuration commands
Enable/disable the DHCPv4 server
Configuring the DHCP address pool name
Specify a boot file for the DHCP client
Configure a default router for a DHCP client
Configure the DNS IP servers
Configure a domain name
Configure lease time
Configure the NetBIOS WINS servers
Configure the NetBIOS node type
Configure subnet and mask
Configure DHCP server options
Configure the range of IP address
Configure the static binding information
Configure the TFTP server domain name
Configure the TFTP server address
Change the number of ping packets
Change the amount of time
Configure DHCP Server to save automatic bindings
Configure a DHCP server to send SNMP notifications
Enable conflict logging on a DHCP server
Enable the DHCP server on a VLAN
Clear commands
Reset all DHCP server and BOOTP counters
Delete an automatic address binding
Show commands
Display the DHCPv4 server address bindings
Display address conflicts
Display DHCPv4 server database agent
Display DHCPv4 server statistics
Display the DHCPv4 server IP pool information
Display DHCPv4 server global configuration information
Event log
Event Log Messages
Link Aggregation Control Protocol—Multi-Active Detection (LACP-MAD)
LACP-MAD commands
Configuration command
show commands
clear command
LACP-MAD overview
Scalability IP Address VLAN and Routing Maximum Values
File Transfers
Downloading switch software
General software download rules
Using TFTP to download software from a server
Downloading from a server to primary flash using TFTP (Menu)
Troubleshooting TFTP download failures
Downloading from a server to flash using TFTP (CLI)
Enabling TFTP (CLI)
Configuring the switch to download software automatically from a TFTP server using auto-TFTP (CLI)
Using SCP and SFTP
Enabling SCP and SFTP
Disabling TFTP and auto-TFTP for enhanced security
Enabling SSH V2 (required for SFTP)
SCP/SFTP operating notes
Troubleshooting SSH, SFTP, and SCP operations
Using Xmodem to download switch software from a PC or UNIX workstation
Downloading to primary flash using Xmodem (Menu)
Downloading to primary or secondary flash using Xmodem and a terminal emulator (CLI)
Using USB to transfer files to and from the switch
Downloading switch software using USB (CLI)
Switch-to-switch download
Switch-to-switch download to primary flash (Menu)
Downloading the OS from another switch (CLI)
Using IMC to update switch software
Copying software images
TFTP: Copying a software image to a remote host (CLI)
Xmodem: Copying a software image from the switch to a serially connected PC or UNIX workstation (CLI)
USB: Copying a software image to a USB device (CLI)
Transferring switch configurations
TFTP: Copying a configuration file to a remote host (CLI)
TFTP: Copying a configuration file from a remote host (CLI)
TFTP: Copying a customized command file to a switch (CLI)
Xmodem: Copying a configuration file to a serially connected PC or UNIX workstation (CLI)
Xmodem: Copying a configuration file from a serially connected PC or UNIX workstation (CLI)
USB: Copying a configuration file to a USB device (CLI)
USB: Copying a configuration file from a USB device (CLI)
Transferring ACL command files
TFTP: Uploading an ACL command file from a TFTP server (CLI)
Xmodem: Uploading an ACL command file from a serially connected PC or UNIX workstation (CLI)
Single copy command
Single copy command
Multiple management switches
Stacking switches
Standalone switches
Crash file options
USB: Uploading an ACL command file from a USB device (CLI)
Copying diagnostic data to a remote host, USB device, PC or UNIX workstation
Copying command output to a destination device (CLI)
Copying Event Log output to a destination device (CLI)
Copying crash data content to a destination device (CLI)
Flight Data Recorder (FDR)
Using USB autorun
Security considerations
Troubleshooting autorun operations
USB auxiliary port LEDs
AutoRun status files
Event log or syslog
Configuring autorun on the switch (CLI)
Autorun secure mode
Operating notes and restrictions
Autorun and configuring passwords
Viewing autorun configuration information
Monitoring and Analyzing Switch Operation
Status and counters data
Accessing status and counters (Menu)
General system information
Accessing system information (Menu)
Accessing system information (CLI)
Collecting processor data with the task monitor (CLI)
Task usage reporting
Switch management address information
Accessing switch management address information (Menu)
Accessing switch management address information (CLI)
Port Status
Viewing port status (CLI)
Viewing port status (Menu)
Viewing port and trunk group statistics (WebAgent)
Port and trunk group statistics and flow control status
Accessing port and trunk statistics (Menu)
Accessing port and trunk group statistics (CLI)
Displaying trunk load balancing statistics
Clearing trunk load balancing statistics
Resetting the port counters
Viewing the switch's MAC address tables
Accessing MAC address views and searches (CLI)
Accessing MAC address views and searches (Menu)
Accessing MSTP Data (CLI)
Viewing internet IGMP status (CLI)
Viewing VLAN information (CLI)
WebAgent status information
Interface monitoring features
Configuring port and static trunk monitoring (Menu)
Configuring port and static trunk monitoring (CLI)
Displaying the monitoring configuration
Configuring the monitor port
Selecting or removing monitoring source interfaces
Troubleshooting approaches
Browser or Telnet access problems
Cannot access the WebAgent
Cannot Telnet into the switch console from a station on the network
Unusual network activity
General problems
The network runs slow; processes fail; users cannot access servers or other devices
Duplicate IP addresses
Duplicate IP addresses in a DHCP network
The switch has been configured for DHCP/Bootp operation, but has not received a DHCP or Bootp reply
802.1Q Prioritization problems
Ports configured for non-default prioritization (level 1 to 7) are not performing the specified action
Addressing ACL problems
ACLs are properly configured and assigned to VLANs, but the switch is not using the ACLs to filter IP layer 3 packets
The switch does not allow management access from a device on the same VLAN
Error (Invalid input) when entering an IP address
Apparent failure to log all "deny" matches
The switch does not allow any routed access from a specific host, group of hosts, or subnet
The switch is not performing routing functions on a VLAN
Routing through a gateway on the switch fails
IGMP-related problems
LACP-related problems
Port-based access control (802.1X)-related problems
QoS-related problems
Radius-related problems
MSTP and fast-uplink problems
SSH-related problems
TACACS-related problems
TimeP, SNTP, or Gateway problems
The switch cannot find the time server or the configured gateway
VLAN-related problems
Fan failure
Mitigating flapping transceivers
Fault finder thresholds
Viewing transceiver information
Viewing information about transceivers (CLI)
MIB support
Viewing transceiver information
Information displayed with the detail parameter
Viewing transceiver information for copper transceivers with VCT support
Testing the Cable
Using the Event Log for troubleshooting switch problems
Event Log entries
Using the Menu
Using the CLI
Clearing Event Log entries
Turning event numbering on
Using log throttling to reduce duplicate Event Log and SNMP messages
Log throttle periods
Example: of event counter operation
Reporting information about changes to the running configuration
Debug/syslog operation
Debug/syslog messaging
Hostname in syslog messages
Logging origin-id
Viewing the identification of the syslog message sender
Debug/syslog destination devices
Debug/syslog configuration commands
Configuring debug/syslog operation
Viewing a debug/syslog configuration
Debug command
Debug messages
Debug destinations
Logging command
Configuring a syslog server
Adding a description for a Syslog server
Adding a priority description
Configuring the severity level for Event Log messages sent to a syslog server
Configuring the system module used to select the Event Log messages sent to a syslog server
Operating notes for debug and Syslog
Diagnostic tools
Port auto-negotiation
Ping and link tests
Tracing the route from the switch to a host address
Halting an ongoing traceroute search
A low maxttl causes traceroute to halt before reaching the destination address
If a network condition prevents traceroute from reaching the destination
Viewing switch configuration and operation
Viewing the startup or running configuration file
Viewing the configuration file (WebAgent)
Viewing a summary of switch operational data
Saving show tech command output to a text file
Customizing show tech command output
Viewing more information on switch operation
Searching for text using pattern matching with show command
Displaying the information you need to diagnose problems
Restoring the factory-default configuration
Resetting to the factory-default configuration
Using the CLI
Using Clear/Reset
Restoring a flash image
Recovering from an empty or corrupted flash state
DNS resolver
Basic operation
Configuring and using DNS resolution with DNS-compatible commands
Configuring a DNS entry
Using DNS names with ping and traceroute: Example:
Viewing the current DNS configuration
Operating notes
Event Log messages
Locating a switch (Locator LED)
MAC Address Management
Determining MAC addresses
Viewing the MAC addresses of connected devices
Viewing the switch's MAC address assignments for VLANs configured on the switch
Viewing the port and VLAN MAC addresses
Remote Device Deployment (TR-069)
Advantages of TR-069
Zero-touch configuration process
Zero-touch configuration setup and execution
CLI commands
Configuration setup
ACS password configuration
When encrypt-credentials is off
When encrypt-credentials is on
ACS URL configuration
ACS username configuration
CPE configuration
CPE password configuration
When encrypt-credentials is on
When encrypt-credentials is off
CPE username configuration
Enable/disable CWMP
Show commands
CWMP configuration and status query
Event logging
System logging
Status/control commands
Network Out-of-Band Management (OOBM)
OOBM and switch applications
OOBM configuration
Entering the OOBM configuration context from the general configuration context
Enabling and disabling OOBM
Enabling and disabling the OOBM port
Setting the OOBM port speed
Configuring an OOBM IPv4 address
Configuring an OOBM IPv4 default gateway
OOBM show commands
Showing the global OOBM and OOBM port configuration
Showing OOBM IP configuration
Showing OOBM ARP information
Application server commands
Application client commands
Support and other resources
Contacting HP
Subscription service
Typographic conventions
Documentation feedback