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HP ProCurve 2512/2524 Switch Series - Troubleshooting

Browser or Console access problems

Cannot access the web browser interface

Cannot Telnet into the switch console from a station on the network

Cannot access the web browser interface

  • Access may be disabled by the Web Agent Enabled parameter in the switch console. Check the setting on this parameter by selecting System Information under Switch Configuration .

  • The switch may not have the correct IP address, subnet mask or gateway. Verify by connecting a console to the switch’s Console port and selecting System Information under Switch Configuration .

    NOTE: If DHCP/Bootp is used to configure the switch, the IP addressing can be verified by selecting:
    • Status and Counters

    • Switch Management Address Information

    also check the DHCP/Bootp server configuration to verify correct IP addressing.

  • If DHCP is used to acquire the IP address for the switch, the IP address "lease time" may have expired so that the IP address has changed.

  • If one or more IP-Authorized managers are configured, the switch allows web browser access only to a device having an authorized IP address.

  • Java applets may not be running on the web browser. They are required for the switch web browser interface to operate correctly. See the online Help on your web browser for how to run the Java applets.

Cannot Telnet into the switch console from a station on the network

  • Telnet access may be disabled by the Inbound Telnet Enabled parameter in the System Information screen of the menu interface:

  • The switch may not have the correct IP address, subnet mask, or gateway. Verify by connecting a console to the switch’s Console port and selecting IP Configuration under Switch Configuration .

    NOTE: If DHCP/Bootp is used to configure the switch, the IP addressing can be verified by selecting:
    • Status and Counters

    • Switch Management Address Information

    also check the DHCP/Bootp server configuration to verify correct IP addressing.

  • If DHCP is used to acquire the IP address for the switch, the IP address "lease time" may have expired so that the IP address has changed.

  • If one or more IP-Authorized managers are configured, the switch allows web browser access only to a device having an authorized IP address.

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Network issues

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

Network activity that exceeds accepted norms may indicate a hardware problem with one or more of the network components, possibly including the switch.

Unusual network activity is usually indicated by the LEDs on the front of the switch or measured with the switch console interface or with a network management tool such as the HP TopTools for Hubs & Switches.

A topology loop can also cause excessive network activity. The event log "FFI" messages can be indicative of this type of problem.

The network runs slow; processes fail; users cannot access servers or other devices

Broadcast storms may be occurring in the network. These may be due to redundant links between nodes.

  • While configuring a port trunk, finish configuring the ports in the trunk before connecting the related cables. Otherwise it creates a number of redundant links(topology loops) inadvertently that will cause broadcast storms.

  • Turn on Spanning Tree Protocol to block redundant links.

  • Check for FFI messages in the Event Log.

Duplicate IP addresses

This is indicated by this Event Log message:

ip: Invalid ARP source: IP address on IP address

Both instances of IP address are the same address, indicating the switch’s IP address has been duplicated somewhere on the network.

Duplicate IP Addresses in a DHCP network

If a DHCP server is used to assign IP addresses in the network and there is a device with a valid IP address that does not appear to communicate properly with the server or other devices, a duplicate IP address may have been issued by the server. This can occur if a client has not released a DHCP-assigned IP address after the intended expiration time and the server "leases" the address to another device. This can also happen, for example: if the server is first configured to issue IP addresses with an unlimited duration, then is subsequently configured to issue IP addresses that will expire after a limited duration. One solution is to configure "reservations" in the DHCP server for specific IP addresses to be assigned to devices having specific MAC addresses.

One indication of a duplicate IP address in a DHCP network is this Event Log message:

ip: Invalid ARP source: IP address on IP address

The switch has been configured for DHCP/Bootp operation, but has not received a DHCP or Bootp reply

When the switch is first configured for DHCP/Bootp operation , or if it is rebooted with this configuration, it immediately begins sending request packets on the network. If the switch does not receive a reply to its DHCP/Bootp requests, it continues to periodically send request packets, but with decreasing frequency. Thus, if a DHCP or Bootp server is not available or accessible to the switch when DHCP/Bootp is first configured, the switch may not immediately receive the desired configuration.

After verifying that the server has become accessible to the switch, reboot the switch to re-start the process.

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IGMP - related problems

IP Multicast (IGMP) traffic that is directed by IGMP does not reach IGMP hosts or a multicast router connected to a port

IP Multicast traffic floods out all ports; IGMP does not appear to filter traffic

IP Multicast (IGMP) traffic that is directed by IGMP does not reach IGMP hosts or a multicast router connected to a port

IGMP must be enabled on the switch and the affected port must be configured for "Auto " or "Forward " operation.

IP Multicast traffic floods out all ports; IGMP does not appear to filter traffic

The IGMP feature does not operate if the switch or VLAN does not have an IP address configured manually or obtained through DHCP/Bootp. To verify whether an IP address is configured for the switch or VLAN, do either of the following:

  • Try using the web browser interface: If the web browser interface can be accessed, then an IP address is configured.

  • Try to telnet to the switch console: If you can Telnet to the switch, then an IP address is configured.

  • Using the switch console interface: From the Main Menu, check the Management Address Information screen by clicking on Switch Management Address Information under Status and Counters

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Spanning tree protocol (STP) - related problems

CAUTION: If STP is enabled, it is recommended to leave the remainder of the STP parameter settings at their default values until there is an opportunity to evaluate STP performance in the network. Because incorrect STP settings can adversely affect network performance, avoid making changes without having a strong understanding of how STP operates. To learn the details of STP operation, refer to the IEEE 802.1d standard.

Broadcasts storms appearing in the network

STP blocks a link in a VLAN even though there are no redundant links in that VLAN

Broadcasts storms appearing in the network

This can occur when there are physical loops (redundant links) in the topology. Where this exists, STP should be enabled on all bridging devices in the topology in order for the loop to be detected.

STP blocks a link in a VLAN even though there are no redundant links in that VLAN

In 802.1Q-compliant switches such as the Switch 2512 and Switch 2524, STP blocks redundant physical links even if they are in separae VLANs. A solution is to use only one, multiple-VLAN (tagged) link between the devices. Also, if ports are available, the bandwidth can be improved in this situation by using a port trunk.

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Stacking - related problems

The stack commander cannot locate any candidates

Stacking operates on the primary VLAN, which in the default configuration is the DEFAULT_VLAN. However, if another VLAN has been configured as the primary VLAN, and the Commander is not on the primary VLAN, then the Commander will not detect Candidates on the primary VLAN.

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Timep or gateway problems

The switch cannot find the Timep server or the configured gateway

Timep and Gateway access are through the primary VLAN, which in the default configuration is the DEFAULT_VLAN.

If the primary VLAN has been moved to another VLAN, it may be disabled or does not have ports assigned to it.

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VLAN - related problems

None of the devices assigned to one or more VLANs on an 802.1Qcompliant switch are being recognized

Link configured for multiple VLANs does not support traffic for one or more VLANs

Duplicate MAC addresses across VLANs

None of the devices assigned to one or more VLANs on an 802.1Qcompliant switch are being recognized

If multiple VLANs are being used on ports connecting 802.1Q-compliant devices, inconsistent VLAN IDs may have been assigned to one or more VLANs. For a given VLAN, the same VLAN ID must be used on all connected 802.1Q-compliant devices.

Link configured for multiple VLANs does not support traffic for one or more VLANs

One or more VLANs may not be properly configured as "Tagged " or "Untagged ". A VLAN assigned to a port connecting two 802.1Q compliant devices must be configured the same on both ports. For example, VLAN_1 and VLAN_2 use the same link between switch "X" and switch "Y".

Figure 1: Example of correct VLAN port assignments on a link

  1. If VLAN_1 (VID=1) is configured as "Untagged " on port 3 on switch "X", then it must also be configured as "Untagged " on port 7 on switch "Y". Make sure that the VLAN ID (VID) is the same on both switches.

  2. Similarly, if VLAN_2 (VID=2) is configured as "Tagged " on the link port on switch "A", then it must also be configured as "Tagged " on the link port on switch "B". Make sure that the VLAN ID (VID) is the same on both switches.

Duplicate MAC addresses across VLANs

Duplicate MAC addresses on different VLANs are not supported and can cause VLAN operating problems. There are no explicit events or statistics to indicate the presence of duplicate MAC addresses in a VLAN environment. However, one symptom that may occur is that a duplicate MAC address can appear in the Port Address Table of one port, and then later appear on another port. (This can also occur in a LAN where there are redundant paths between nodes and Spanning Tree is turned off.)

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Diagnostic tools

Ping and Link Tests

CLI: Ping or Link Tests

Ping and Link Tests

The Ping test and the Link test are point-to-point tests between your switch and another IEEE 802.3-compliant device on your network. These tests can tell you whether the switch is communicating properly with another device.

NOTE: To respond to a Ping test or a Link test, the device trying to reach must be IEEE 802.3-compliant.

Ping Test: This is a test of the path between the switch and another device on the same or another IP network that can respond to IP packets (ICMP Echo Requests).

Link Test: This is a test of the connection between the switch and a designated network device on the same LAN (or VLAN, if configured). During the link test, IEEE 802.2 test packets are sent to the designated network device in the same VLAN or broadcast domain. The remote device must be able to respond with an 802.2 Test Response Packet.

Executing ping or link tests:

Below is the procedure to perform the ping test or link test:

  1. Click on the Diagnostics tab.

  2. Click on PingTest or Link Test .

  3. Select Ping Test (the default) or Link Test .

  4. For a Ping test, enter the IP address of the target device. For a Link test, enter the MAC address of the target device in the Designation IP/MAC Address field.

  5. Select the number of tries (packets) and the timeout for each try from the drop-down menus in the Number of Packets to Send field.

  6. Click on Start to begin the test.

Successes indicates the number of Ping or Link packets that successfully completed the most recent test.

Failures indicates the number of Ping or Link packets that were unsuccessful in the last test. Failures indicate connectivity or network performance problems (such as overloaded links or devices).

Destination IP/MAC Address is the network address of the target, or destination, device to test a connection with the switch. An IP address is in the X.X.X.X format where X is a decimal number between 0 and 255. A MAC address is made up of 12 hexadecimal digits, for example, 0060b0-080400.

Number of Packets to Send is the number of times you want the switch to attempt to test a connection.

Timeout in Seconds is the number of seconds to allow per attempt to test a connection before determining that the current attempt has failed.

To halt a Link or Ping test before it concludes, click on the Stop button.

To reset the screen to its default settings, click on the Defaults button.

CLI: Ping or Link Tests

Ping Test: Single or multiple ping tests with varying repititions and timeout periods can be issued. The defaults and ranges are:

  • Repetitions: 1 (1 - 999)

  • Timeout: 5 seconds (1 - 256 seconds)

Syntax:

ping <ip-address> [repetitions <1 - 999>] [timeout <1 - 256>]

To halt a ping test before it concludes, press Ctrl C

Link Test: Single or multiple link tests with varying repititions and timeout periods. The defaults are:

  • Repetitions: 1 (1 - 9999)

  • Timeout: 5 seconds (1 - 256 seconds)

Syntax:

link <MAC-address> [repetitions <1-999>] [timeout <1-256>]

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Displaying the configuration file

The complete switch configuration is contained in a file that can be browsed from either the web browser interface or the CLI. It may be useful in some troubleshooting scenarios to view the switch configuration.

CLI: Viewing the configuration file

Web: Viewing the configuration file

CLI: Viewing the configuration file

Syntax:

write terminal
Displays the running configuration.

show config
Displays the startup configuration.

Web: Viewing the configuration file

To display the running configuration, through the web browser interface:

  1. Click on the Diagnostics tab.

  2. Click on Configuration Report .

  3. Use the right-side scroll bar to scroll through the configuration listing.

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CLI Administrative and troubleshooting commands

Syntax
Description
show version
Shows the software version currently running on the switch.
show boot - history
Displays the switch shutdown history.
show history
Displays the current command history
[no] page
Toggles the paging mode for display commands between continuous listing and per page listing.
Setup
Displays the Switch Setup screen from the menu interface.
Repeat
Repeatedly executes the previous command until a key is pressed.
kill
Terminates all other active sessions.

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Restoring the factory-default configuration

This process momentarily interrupts the switch operation, clears any passwords, clears the console event log, resets the network counters to zero, performs a complete self test, and reboots the switch into its factory default configuration including deleting an IP address. There are two methods for resetting to the factory default configuration:

NOTE: HP recommends to save configuration to a TFTP server before resetting the switch to its factory-default configuration. Configuration can also be saved via Xmodem, to a directly connected PC.

CLI: Resetting to the factory-default configuration

This command operates at any level except the Operator level.

Syntax:

erase startup-configuration
Deletes the startup-config file in flash so that the switch will reboot with its factory-default configuration.

Clear/Reset: Resetting to the factory-default configuration

To execute the factory default reset, perform these steps:

  1. Using pointed objects, simultaneously press both the Reset and Clear buttons on the front of the switch.

  2. Continue to press the Clear button while releasing the Reset button.

  3. When the Self Test LED begins to flash, release the Clear button.

    The switch will then complete its self test and begin operating with the configuration restored to the factory default settings.

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