Diagnostic tools

Port auto-negotiation

When a link LED does not light (indicating loss of link between two devices), the most common reason is a failure of port auto-negotiation between the connecting ports. If a link LED fails to light when you connect the switch to a port on another device, do the following:

Ensure that the switch port and the port on the attached end-node are both set to Auto mode.
If the attached end-node does not have an Auto mode setting, you must manually configure the switch port to the same setting as the end-node port. See Port Status and Configuration.

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 you are trying to reach must be IEEE 802.3-compliant.

Ping test

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). To use the ping (or traceroute) command with host names or fully qualified domain names, see DNS resolver.

Link test

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 (WebAgent)

To start a ping or link test in the WebAgent:

In the navigation pane, click Troubleshooting.
Click Ping/Link Test.
Click Start.
To halt a link or ping test before it concludes, click Stop.

For an Example: of the text screens, see Ping test and link test screen on the WebAgent.

Ping test and link test screen on the WebAgent

Destination IP Address is the network address of the target, or destination, device to which you want 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.

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.

Testing the path between the switch and another device on an IP network

The ping test uses ICMP echo requests and ICMP echo replies to determine if another device is alive. It also measures the amount of time it takes to receive a reply from the specified destination. The ping command has several extended commands that allow advanced checking of destination availability.

Syntax:

ping <ip-address | hostname> [repetitions <1-10000>] [timeout <1-60>] [source < ip-address | <vlan-id> | loopback <0-7>> ] [data-size <0-65471>] [data-fill <0-1024>] [ip-option <record-route | loose-source-route | strict-source-route | include-timestamp | include-timestamp-and-address | include timestamp-from >] [tos <0-255>]

ping6 <ipv6-address | hostname> [repetitions <1-10000>] [timeout <1-60>] [source < ip-address | vlan-id | loopback <0-7>> ] [data-size <0-65471>] [data-fill <0-1024>]

Sends ICMP echo requests to determine if another device is alive.

<ip-address | hostname>

Target IP address or hostname of the destination node being pinged

repetitions <1-10000>

Number of ping packets sent to the destination address.

Default: 1

timeout <1-60>

Timeout interval in seconds; the ECHO REPLY must be received before this time interval expires for the ping to be successful.

Default: 5

source <ip-addr | vid | loopback <0-7>>

Source IP address, VLAN ID, or loopback address used for the ping.

The source IP address must be owned by the router.

If a VLAN is specified, the IP address associated with the specified VLAN is used.

data-size <0-65471>

Size of packet sent.

Default: 0 (zero)

data-fill <0-1024>

The data pattern in the packet.

Default: Zero length string

ip-option

Specify an IP option, such as loose or strict source routing, or an include-timestamp option:

include-timestamp: Adds the timestamp option to the IP header. The timestamp displays the amount of travel time to and from a host.

Default: 9

include-timestamp-and-address: Records the intermediate router's timestamp and IP address.

Default: 4

include-timestamp-from: Records the timestamp of the specified router addresses.

loose-source-route <IP-addr>: The loose-source-route option prompts for the IP address of each source IP on the path. It allows you to specify the IP addresses that you want the ping packet to go through; the packet may go through other IP addresses as well.

record-route <1-9>: Displays the IP addresses of the interfaces that the ping packet goes through on its way to the destination and on the way back.

When specified without loose or strict recording, the source route is not recorded. The source route is automatically recorded when loose or strict source routing is enabled.

Default: 9

strict-source-route <IP-addr>: Restricts the ping packet to only those IP addresses that have been specified and no other addresses.

tos <0-255>

Specifies the type of service to be entered in the header packet.

Default: 0 (zero)

Ping tests

HP Switch# ping 10.10.10.10
10.10.10.10 is alive, time = 15 ms

HP Switch# ping 10.10.10.10 repetitions 3
10.10.10.10 is alive, iteration 1, time = 15 ms
10.10.10.10 is alive, iteration 1, time = 15 ms
10.10.10.10 is alive, iteration 1, time = 15 ms

HP Switch# ping 10.10.10.10 timeout 2
10.10.10.10 is alive, time = 10 ms

HP Switch# ping 10.11.12.13
The destination address is unreachable.

Halting a ping test

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


	NOTE: To use the `ping` (or `traceroute`) command with host names or fully qualified domain names, see DNS resolver.

Issuing single or multiple link tests

Single or multiple link tests can have varying repetitions and timeout periods. The defaults are:

Repetitions: 1 (1 to 999)
Timeout: 5 seconds (1 to 256 seconds)

Syntax:

link <mac-address> [repetitions <1-999>] [timeout <1-256>] [vlan <vlan-id>]

Example:

Link tests

Tracing the route from the switch to a host address

The traceroute command enables you to trace the route from the switch to a host address.

This command outputs information for each (router) hop between the switch and the destination address. Note that every time you execute traceroute, it uses the same default settings unless you specify otherwise for that instance of the command.

Syntax:

traceroute <ip-address | hostname> [maxttl <1-255>] [minttl <1-255>] [probes <1-5>] [source <ip-address | source-vlan <vid> | loopback <0-7> ] [dstport <1-34000>] [srcport <1-34000>] [ip-option <record-route | loose-source-route | strict-source-route | include-timestamp | include-timestamp-and-address | include timestamp-from> ] [<timeout 1-120>]

Lists the IP address or hostname of each hop in the route, plus the time in microseconds for the traceroute packet reply to the switch for each hop.

<ip-address | hostname>

The IP address or hostname of the device to which to send the traceroute.

[minttl <1-255>]

For the current instance of traceroute, changes the minimum number of hops allowed for each probe packet sent along the route.

If minttl is greater than the actual number of hops, the output includes only the hops at and above the minttl threshold. (The hops below the threshold are not listed.)

If minttl matches the actual number of hops, only that hop is shown in the output.

If minttl is less than the actual number of hops, all hops are listed.

For any instance of traceroute, if you want a minttl value other than the default, you must specify that value.

(Default: 1)

[maxttl <1-255>]

For the current instance of traceroute, changes the maximum number of hops allowed for each probe packet sent along the route.

If the destination address is further from the switch than maxttl allows, traceroute lists the IP addresses for all hops it detects up to the maxttl limit.

For any instance of traceroute, if you want a maxttl value other than the default, you must specify that value.

(Default: 30)

[probes <1-5>]

For the current instance of traceroute, changes the number of queries the switch sends for each hop in the route.

For any instance of traceroute, if you want a probes value other than the default, you must specify that value.

(Default: 3)

[source <ip-addr | vid | loopback <0-7>> ]

The source IPv4 address, VLAN ID, or Loopback address.

[dstport <1-34000>]

Destination port.

[srcport <1-34000>]

Source port.

[ip-option]

Specify an IP option, such as loose or strict source routing, or an include-timestamp option:

[include-timestamp]: Adds the timestamp option to the IP header. The timestamp displays the amount of travel time to and from a host.

Default: 9

[include-timestamp-and-address]: Records the intermediate router's timestamp and IP address.

Default: 4

[loose-source-route <IP-addr>]: Prompts for the IP address of each source IP on the path.

It allows you to specify the IP addresses that you want the ping packet to go through; the packet may go through other IP addresses as well.

[record-route <1-9>]: Displays the IP addresses of the interfaces that the ping packet goes through on its way to the destination and on the way back.

When specified without loose or strict recording, the source route is not recorded. The source route is automatically recorded when loose or strict source routing is enabled.

Default: 9

[strict-source-route <IP-addr>]: Restricts the ping packet to only those IP addresses that have been specified and no other addresses.

[timeout <1-120>]: For the current instance of traceroute, changes the timeout period the switch waits for each probe of a hop in the route.

For any instance of traceroute, if you want a timeout value other than the default, you must specify that value.

(Default: 5 seconds)

NOTE: For information about traceroute6, see the IPv6 Configuration Guide for your switch.

Halting an ongoing traceroute search

Press the [Ctrl] [C] keys.

A low maxttl causes traceroute to halt before reaching the destination address

Executing traceroute with its default values for a destination IP address that is four hops away produces a result similar to this:

A completed traceroute enquiry

Continuing from the previous Example: (A completed traceroute enquiry), executing traceroute with an insufficient maxttl for the actual hop count produces an output similar to this:

Incomplete traceroute because of low maxttl setting

If a network condition prevents traceroute from reaching the destination

Common reasons for traceroute failing to reach a destination include:

Timeouts (indicated by one asterisk per probe, per hop)
Unreachable hosts
Unreachable networks
Interference from firewalls
Hosts configured to avoid responding

Executing traceroute where the route becomes blocked or otherwise fails results in an output marked by timeouts for all probes beyond the last detected hop. For example, with a maximum hop count of 7 (maxttl = 7), where the route becomes blocked or otherwise fails, the output appears similar to this:

Traceroute failing to reach the destination address

prev	up	next
Debug/syslog operation	home	Viewing switch configuration and operation

<`ip-address` \| `hostname`>	Target IP address or hostname of the destination node being pinged
`repetitions <1-10000>`	Number of ping packets sent to the destination address. Default: 1
`timeout <1-60>`	Timeout interval in seconds; the ECHO REPLY must be received before this time interval expires for the ping to be successful. Default: 5
`source` <`ip-addr` \| `vid` \| `loopback <0-7>>`	Source IP address, VLAN ID, or loopback address used for the ping. The source IP address must be owned by the router. If a VLAN is specified, the IP address associated with the specified VLAN is used.
`data-size <0-65471>`	Size of packet sent. Default: 0 (zero)
`data-fill <0-1024>`	The data pattern in the packet. Default: Zero length string
`ip-option`	Specify an IP option, such as loose or strict source routing, or an include-timestamp option: `include-timestamp`: Adds the timestamp option to the IP header. The timestamp displays the amount of travel time to and from a host. Default: 9 `include-timestamp-and-address`: Records the intermediate router's timestamp and IP address. Default: 4 `include-timestamp-from`: Records the timestamp of the specified router addresses. `loose-source-route <IP-addr>`: The `loose-source-route` option prompts for the IP address of each source IP on the path. It allows you to specify the IP addresses that you want the ping packet to go through; the packet may go through other IP addresses as well. `record-route <1-9>`: Displays the IP addresses of the interfaces that the ping packet goes through on its way to the destination and on the way back. When specified without loose or strict recording, the source route is not recorded. The source route is automatically recorded when loose or strict source routing is enabled. Default: 9 `strict-source-route <IP-addr>`: Restricts the ping packet to only those IP addresses that have been specified and no other addresses.
`tos <0-255>`	Specifies the type of service to be entered in the header packet. Default: 0 (zero)

<`ip-address` \| `hostname`>	The IP address or hostname of the device to which to send the traceroute.
[`minttl <1-255>`]	For the current instance of `traceroute`, changes the minimum number of hops allowed for each probe packet sent along the route. If `minttl` is greater than the actual number of hops, the output includes only the hops at and above the `minttl` threshold. (The hops below the threshold are not listed.) If `minttl` matches the actual number of hops, only that hop is shown in the output. If `minttl` is less than the actual number of hops, all hops are listed. For any instance of `traceroute`, if you want a `minttl` value other than the default, you must specify that value. (Default: 1)
[`maxttl <1-255>`]	For the current instance of `traceroute`, changes the maximum number of hops allowed for each probe packet sent along the route. If the destination address is further from the switch than `maxttl` allows, `traceroute` lists the IP addresses for all hops it detects up to the `maxttl` limit. For any instance of `traceroute`, if you want a `maxttl` value other than the default, you must specify that value. (Default: 30)
[`probes <1-5>`]	For the current instance of `traceroute`, changes the number of queries the switch sends for each hop in the route. For any instance of `traceroute`, if you want a probes value other than the default, you must specify that value. (Default: 3)
[`source` <`ip-addr` \| `vid` \| `loopback <0-7>`> ]	The source IPv4 address, VLAN ID, or Loopback address.
[`dstport <1-34000>`]	Destination port.
[`srcport <1-34000>`]	Source port.
[`ip-option`]	Specify an IP option, such as loose or strict source routing, or an include-timestamp option: `[include-timestamp]`: Adds the timestamp option to the IP header. The timestamp displays the amount of travel time to and from a host. Default: 9 `[include-timestamp-and-address]`: Records the intermediate router's timestamp and IP address. Default: 4 `[loose-source-route <IP-addr>]`: Prompts for the IP address of each source IP on the path. It allows you to specify the IP addresses that you want the ping packet to go through; the packet may go through other IP addresses as well. `[record-route <1-9>]`: Displays the IP addresses of the interfaces that the ping packet goes through on its way to the destination and on the way back. When specified without loose or strict recording, the source route is not recorded. The source route is automatically recorded when loose or strict source routing is enabled. Default: 9 `[strict-source-route <IP-addr>]`: Restricts the ping packet to only those IP addresses that have been specified and no other addresses. `[timeout <1-120>]`: For the current instance of `traceroute`, changes the timeout period the switch waits for each probe of a hop in the route. For any instance of `traceroute`, if you want a timeout value other than the default, you must specify that value. (Default: 5 seconds)


	NOTE: For information about `traceroute6`, see the IPv6 Configuration Guide for your switch.