Troubleshooting
CH A P T E R
37
Troubleshooting
This chapter describes how to identify and resolve software problems related to the Cisco IOS software
on the Cisco ME 3800X and ME 3600X switch.
You can use the command-line interface (CLI) to identify and solve problems.
Additional troubleshooting information related to hardware is provided in the hardware installation
guide.
Note
For complete syntax and usage information for the commands used in this chapter, see the command
reference for this release and the Cisco IOS Command Summary, Release 12.2.
•
Recovering from a Lost or Forgotten Password, page 2
Note
Recovery procedures require that you have physical access to the switch.
•
Preventing Autonegotiation Mismatches, page 6
•
SFP Module Security and Identification, page 7
•
Monitoring SFP Module Status, page 7
•
Monitoring Temperature, page 7
•
Using Ping, page 8
•
Using Layer 2 Traceroute, page 8
•
Using IP Traceroute, page 10
•
Using TDR, page 37-12
•
Using Debug Commands, page 12
•
Using the crashinfo File, page 14
•
Using On-Board Failure Logging, page 15
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Recovering from a Lost or Forgotten Password
Recovering from a Lost or Forgotten Password
The default configuration for the switch allows an end user to recover from a lost password by
interrupting the boot process during power-on and by entering a new password.
Note
On these switches, a system administrator can disable some of the functionality of password recovery
by allowing an end user to reset a password only by agreeing to return to the default configuration. If
you are an end user trying to reset a password when password recovery has been disabled, a status
message shows this during the recovery process.
Disabling password recovery provides configuration file security by preventing unauthorized users from
accessing the configuration file.
The Cisco ME switch boot loader uses break-key detection to stop the automatic boot sequence for the
password recovery purpose.
Note
The break key character is different for each operating system.
On a SUN work station running UNIX, Ctrl-C is the break key.
On a PC running Windows XP or 2000, Ctrl-Break is the break key.
Cisco TAC has tabulated break keys for most common operating systems and an alternative break key
sequence for those terminal emulators that do not support the break keys. To see that list go to:
http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a0080174a34.shtml
These sections describes how to recover a forgotten or lost switch password:
•
Procedure with Password Recovery Enabled, page 3
•
Procedure with Password Recovery Disabled, page 5
You enable or disable password recovery by using the service password-recovery global configuration
command.
Follow the steps in this procedure if you have forgotten or lost the switch password.
Step 1
Connect a terminal or PC with terminal-emulation software to the switch console port.
Step 2
Set the line speed on the emulation software to 9600 baud.
Step 3
Power off the switch.
Reconnect the power cord to the switch.
Step 4
After the switch performs POST, the switch begins the autoboot process. The boot loader prompts the
user for a break key character during the boot-up sequence, as shown in this example:
***** The system will autoboot in 5 seconds *****
Send a break key to prevent autobooting.
You must enter the break key on the console terminal within 5 seconds of receiving the message that the
system will autoboot. The System LED flashes green until the break key is accepted. After the break key
is accepted, the System LED turns off until after the switch boots.
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Recovering from a Lost or Forgotten Password
Several lines of information about the software appear with instructions, informing you if the password
recovery procedure has been disabled or not.
•
If you see a message that begins with this:
The system has been interrupted, or encountered an error during initializion of the
flash filesystem. The following commands will initialize the flash filesystem, and
finish loading the operating system software:
flash_init
load_helper
boot
proceed to the “Procedure with Password Recovery Enabled” section on page 3, and follow the
steps.
•
If you see a message that begins with this:
The password-recovery mechanism has been triggered, but is currently disabled.
proceed to the “Procedure with Password Recovery Disabled” section on page 5, and follow the
steps.
Step 5
After recovering the password, reload the switch:
Switch> reload
Proceed with reload? [confirm] y
Procedure with Password Recovery Enabled
If the password-recovery mechanism is enabled, this message appears:
The system has been interrupted, or encountered an error during initializion of the flash
filesystem. The following commands will initialize the flash filesystem, and finish
loading the operating system software:
flash_init
load_helper
boot
Step 1
Initialize the flash file system:
switch: flash_init
Step 2
If you had set the console port speed to anything other than 9600, it has been reset to that particular
speed. Change the emulation software line speed to match that of the switch console port.
Step 3
Load any helper files:
switch: load_helper
Step 4
Display the contents of flash memory:
switch: dir flash:
The switch file system appears:
Directory of flash:
13 drwx
192
11 -rwx
5825
18 -rwx
720
Mar 01 1993 22:30:48 image-name-mz.122-50-EX
Mar 01 1993 22:31:59 config.text
Mar 01 1993 02:21:30 vlan.dat
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Recovering from a Lost or Forgotten Password
16128000 bytes total (10003456 bytes free)
Step 5
Rename the configuration file to config.text.old.
This file contains the password definition.
switch: rename flash:config.text flash:config.text.old
Step 6
Boot the system:
switch: boot
You are prompted to start the setup program. Enter N at the prompt:
Continue with the configuration dialog? [yes/no]: N
Step 7
At the switch prompt, enter privileged EXEC mode:
Switch> enable
Step 8
Rename the configuration file to its original name:
Switch# rename flash:config.text.old flash:config.text
Step 9
Copy the configuration file into memory:
Switch# copy flash:config.text system:running-config
Source filename [config.text]?
Destination filename [running-config]?
Press Return in response to the confirmation prompts.
The configuration file is now reloaded, and you can change the password.
Step 10
Enter global configuration mode:
Switch# configure terminal
Step 11
Change the password:
Switch (config)# enable secret password
The secret password can be from 1 to 25 alphanumeric characters, can start with a number, is case
sensitive, and allows spaces but ignores leading spaces.
Step 12
Return to privileged EXEC mode:
Switch (config)# exit
Switch#
Step 13
Write the running configuration to the startup configuration file:
Switch# copy running-config startup-config
The new password is now in the startup configuration.
Note
This procedure is likely to leave your switch virtual interface in a shutdown state. You can
identify this interface by entering the show running-config privileged EXEC command. To
re-enable the interface, enter the interface vlan vlan-id global configuration command, and
specify the VLAN ID of the shutdown interface. With the switch in interface configuration
mode, enter the no shutdown command.
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Recovering from a Lost or Forgotten Password
Step 14
Reload the switch:
Switch# reload
Procedure with Password Recovery Disabled
If the password-recovery mechanism is disabled, this message appears:
The password-recovery mechanism has been triggered, but
is currently disabled. Access to the boot loader prompt
through the password-recovery mechanism is disallowed at
this point. However, if you agree to let the system be
reset back to the default system configuration, access
to the boot loader prompt can still be allowed.
Would you like to reset the system back to the default configuration (y/n)?
Caution
Returning the switch to the default configuration results in the loss of all existing configurations. We
recommend that you contact your system administrator to verify if there are backup switch and VLAN
configuration files.
Note
Disabling password recovery provides configuration file security by preventing unauthorized users from
accessing the configuration file.
•
If you enter n (no), the normal boot process continues as if the break key had not been pressed; you
cannot access the boot loader prompt, and you cannot enter a new password. You see the message:
Press Enter to continue........
•
Step 1
If you enter y (yes), the configuration file in flash memory and the VLAN database file are deleted.
When the default configuration loads, you can reset the password.
Elect to continue with password recovery and lose the existing configuration:
Would you like to reset the system back to the default configuration (y/n)? Y
Step 2
Load any helper files:
Switch: load_helper
Step 3
Display the contents of flash memory:
switch: dir flash:
The switch file system appears:
Directory of flash:
13 drwx
192
Mar 01 1993 22:30:48 image-name-mz.122-50-SE
16128000 bytes total (10003456 bytes free)
Step 4
Boot the system:
Switch: boot
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Preventing Autonegotiation Mismatches
You are prompted to start the setup program. To continue with password recovery, enter N at the prompt:
Continue with the configuration dialog? [yes/no]: N
Step 5
At the switch prompt, enter privileged EXEC mode:
Switch> enable
Step 6
Enter global configuration mode:
Switch# configure terminal
Step 7
Change the password:
Switch (config)# enable secret password
The secret password can be from 1 to 25 alphanumeric characters, can start with a number, is case
sensitive, and allows spaces but ignores leading spaces.
Step 8
Return to privileged EXEC mode:
Switch (config)# exit
Switch#
Step 9
Write the running configuration to the startup configuration file:
Switch# copy running-config startup-config
The new password is now in the startup configuration.
Note
Step 10
This procedure is likely to leave your switch virtual interface in a shutdown state. You can
identify this interface by entering the show running-config privileged EXEC command. To
re-enable the interface, enter the interface vlan vlan-id global configuration command, and
specify the VLAN ID of the shutdown interface. With the switch in interface configuration
mode, enter the no shutdown command.
You must now reconfigure the switch. If the system administrator has the backup switch and VLAN
configuration files available, you should use those.
Preventing Autonegotiation Mismatches
The IEEE 802.3ab autonegotiation protocol manages the switch settings for speed (10, 100, and
1000 Mbps, excluding SFP module ports) and duplex (half or full). There are situations when this
protocol can incorrectly align these settings, reducing performance. A mismatch occurs under these
circumstances:
•
A manually set speed or duplex parameter is different from the manually set speed or duplex
parameter on the connected port.
•
A port is set to autonegotiate, and the connected port is set to full duplex with no autonegotiation.
To maximize switch performance and ensure a link, follow one of these guidelines when changing the
settings for duplex and speed:
•
Let both ports autonegotiate both speed and duplex.
•
Manually set the speed and duplex parameters for the ports on both ends of the connection.
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SFP Module Security and Identification
Note
If a remote device does not autonegotiate, configure the duplex settings on the two ports to match. The
speed parameter can adjust itself even if the connected port does not autonegotiate.
SFP Module Security and Identification
Cisco small form-factor pluggable (SFP) modules have a serial EEPROM that contains the module serial
number, the vendor name and ID, a unique security code, and cyclic redundancy check (CRC). When an
SFP module is inserted in the switch, the switch software reads the EEPROM to verify the serial number,
vendor name and vendor ID, and recompute the security code and CRC. If the serial number, the vendor
name or vendor ID, the security code, or CRC is invalid, the software generates a security error message
and places the interface in an error-disabled state.
Note
The security error message references the GBIC_SECURITY facility. The switch supports SFP modules
and does not support GBIC modules. Although the error message text refers to GBIC interfaces and
modules, the security messages actually refer to the SFP modules and module interfaces. For more
information about error messages, see the system message guide for this release.
If you are using a non-Cisco SFP module, remove the SFP module from the switch, and replace it with
a Cisco module. After inserting a Cisco SFP module, use the errdisable recovery cause gbic-invalid
global configuration command to verify the port status, and enter a time interval for recovering from the
error-disabled state. After the elapsed interval, the switch brings the interface out of the error-disabled
state and retries the operation. For more information about the errdisable recovery command, see the
command reference for this release.
If the module is identified as a Cisco SFP module, but the system is unable to read vendor-data
information to verify its accuracy, an SFP module error message is generated. In this case, you should
remove and re-insert the SFP module. If it continues to fail, the SFP module might be defective.
Monitoring SFP Module Status
You can check the physical or operational status of an SFP module by using the show interfaces
transceiver privileged EXEC command. This command shows the operational status, such as the
temperature and the current for an SFP module on a specific interface and the alarm status. You can also
use the command to check the speed and the duplex settings on an SFP module. For more information,
see the show interfaces transceiver command in the command reference for this release.
Monitoring Temperature
The switch monitors the temperature conditions. The switch also uses the temperature information to
control the fans. The temperature value is the temperature in the switch (not the external temperature).
Enter the show env temperature privileged EXEC command to see if the temperature is okay or faulty.
You can use the show env temperature status privileged EXEC command to display the temperature
value, state, and thresholds. You can configure a high and low threshold level (in Celsius) to generate an
alert by using the system env temperature alert {high | low} value global configuration command.
The show env temperature status command displays the temperature value, state, and thresholds.
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Using Ping
These are examples of output from the show env temperature and show env temperature status
commands:
Switch> show env temperature
SYSTEM TEMPERATURE is GREEN
Switch> show env temperature status
SYSTEM Temperature Value: 35.5 Degree Celsius
SYSTEM Temperature State: GREEN
SYSTEM Low Temperature Alert Threshold: 0.0 Degree Celsius
SYSTEM Low Temperature Shutdown Threshold: -20.0 Degree Celsius
SYSTEM High Temperature Alert Threshold: 58.0 Degree Celsius
SYSTEM High Temperature Shutdown Threshold: 80.0 Degree Celsius
POWER SUPPLY 1 Temperature Value: 32.7500 Degree Celsius
POWER SUPPLY 1 Temperature Alert Threshold: 85.0000 Degree Celsius
POWER SUPPLY 1 Temperature Shutdown Threshold: 110.0000 Degree Celsius
FAN TRAY 2: No Temperature Information Provided
For more information, see the command reference for this release.
Using Ping
The switch supports IP ping, which you can use to test connectivity to remote hosts. Ping sends an echo
request packet to an address and waits for a reply. To ping a host in a different IP subnetwork from the
switch, you must have IP routing configured to route between the subnets, and a static route to the
destination might also be appropriate. If you need to enable or configure IP routing, see Chapter 29,
“Configuring IP Unicast Routing.”
Beginning in privileged EXEC mode, use the ping command to ping another device on the network from
the switch:
Command
Purpose
ping [host | address]
Ping a remote host by supplying the hostname or IP network
address.
Note
Though other protocol keywords are available with the
ping command, they are not supported in this release.
To end a ping session, simultaneously press and release the Ctrl, Shift, and 6 keys, and then press the
X key.
Using Layer 2 Traceroute
•
Understanding Layer 2 Traceroute, page 9
•
Layer 2 Traceroute Usage Guidelines, page 9
•
Displaying the Physical Path, page 10
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Using Layer 2 Traceroute
Understanding Layer 2 Traceroute
The Layer 2 traceroute feature allows the switch to identify the physical path that a packet takes from a
source device to a destination device. Layer 2 traceroute supports only unicast source and destination
MAC addresses. It finds the path by using the MAC address tables of the switches in the path. When the
switch detects a device in the path that does not support Layer 2 traceroute, the switch continues to send
Layer 2 trace queries and lets them time out.
Note
Layer 2 traceroute is not available only on ports configured with service instances.
The switch can only identify the path from the source device to the destination device. It cannot identify
the path that a packet takes from source host to the source device or from the destination device to the
destination host.
Layer 2 Traceroute Usage Guidelines
•
Ports configured with service instances do not support Layer 2 traceroute.
•
Cisco Discovery Protocol (CDP) must be enabled on all the devices in the network. For Layer 2
traceroute to function properly, do not disable CDP. CDP is enabled by default. If any devices in the
physical path are transparent to CDP, the switch cannot identify the path through these devices. For
more information about enabling CDP, see Chapter 21, “Configuring CDP.”
•
A switch is reachable from another switch when you can test connectivity by using the ping
privileged EXEC command. All switches in the physical path must be reachable from each other.
•
The maximum number of hops identified in the path is ten.
•
You can enter the traceroute mac or the traceroute mac ip privileged EXEC command on a switch
that is not in the physical path from the source device to the destination device. All switches in the
path must be reachable from this switch.
•
The traceroute mac command output shows the Layer 2 path only when the specified source and
destination MAC addresses belong to the same VLAN. If you specify source and destination MAC
addresses that belong to different VLANs, the Layer 2 path is not identified, and an error message
appears.
•
If you specify a multicast source or destination MAC address, the path is not identified, and an error
message appears.
•
If the source or destination MAC address belongs to multiple VLANs, you must specify the VLAN
to which both the source and destination MAC addresses belong. If the VLAN is not specified, the
path is not identified, and an error message appears.
•
The traceroute mac ip command output shows the Layer 2 path when the specified source and
destination IP addresses belong to the same subnet. When you specify the IP addresses, the switch
uses the Address Resolution Protocol (ARP) to associate the IP addresses with the corresponding
MAC addresses and the VLAN IDs.
– If an ARP entry exists for the specified IP address, the switch uses the associated MAC address
and identifies the physical path.
– If an ARP entry does not exist, the switch sends an ARP query and tries to resolve the IP
address. If the IP address is not resolved, the path is not identified, and an error message
appears.
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Using IP Traceroute
•
When multiple devices are attached to one port through hubs (for example, multiple CDP neighbors
are detected on a port), the Layer 2 traceroute feature is not supported. When more than one CDP
neighbor is detected on a port, the Layer 2 path is not identified, and an error message appears.
•
This feature is not supported in Token Ring VLANs.
Displaying the Physical Path
You can display the physical path that a packet takes from a source device to a destination device by
using one of these privileged EXEC commands:
•
tracetroute mac [interface interface-id] {source-mac-address} [interface interface-id]
{destination-mac-address} [vlan vlan-id] [detail]
•
tracetroute mac ip {source-ip-address | source-hostname}{destination-ip-address |
destination-hostname} [detail]
For more information, see the command reference for this release.
Using IP Traceroute
•
Understanding IP Traceroute, page 10
•
Executing IP Traceroute, page 11
Understanding IP Traceroute
You can use IP traceroute to identify the path that packets take through the network on a hop-by-hop
basis. The command output displays all network layer (Layer 3) devices, such as routers, that the traffic
passes through on the way to the destination.
Your switches can participate as the source or destination of the traceroute privileged EXEC command
and might or might not appear as a hop in the traceroute command output. If the switch is the destination
of the traceroute, it is displayed as the final destination in the output. Intermediate switches do not show
up in the output if they are only bridging the packet from one port to another within the same VLAN.
However, if the intermediate switch is a multilayer switch that is routing a particular packet, this switch
shows up as a hop in the output.
The traceroute privileged EXEC command uses the Time To Live (TTL) field in the IP header to cause
routers and servers to generate specific return messages. Traceroute starts by sending a User Datagram
Protocol (UDP) datagram to the destination host with the TTL field set to 1. If a router finds a TTL value
of 1 or 0, it drops the datagram and sends an Internet Control Message Protocol (ICMP)
time-to-live-exceeded message to the sender. Traceroute finds the address of the first hop by examining
the source address field of this message.
To identify the next hop, traceroute sends a UDP packet with a TTL value of 2. The first router
decrements the TTL field by 1 and sends the datagram to the next router. The second router sees a TTL
value of 1, discards the datagram, and returns the time-to-live-exceeded message to the source. This
process continues until the TTL is incremented to a value large enough for the datagram to reach the
destination host (or until the maximum TTL is reached).
To learn when a datagram reaches its destination, traceroute sets the UDP destination port number in the
datagram to a very large value that the destination host is unlikely to be using. When a host receives a
datagram destined to itself containing a destination port number that is unused locally, it sends an ICMP
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Using IP Traceroute
port-unreachable error to the source. Because all errors except port-unreachable errors come from
intermediate hops, the receipt of a port-unreachable error means that this message was sent by the
destination port.
Executing IP Traceroute
Beginning in privileged EXEC mode, follow this step to trace that the path packets take through the
network:
Note
Command
Purpose
traceroute ip host
Trace the path that packets take through the network.
Though other protocol keywords are available with the traceroute privileged EXEC command, they are
not supported in this release.
This example shows how to perform a traceroute to an IP host:
Switch# traceroute ip 171.9.15.10
Type escape sequence to abort.
Tracing the route to 171.69.115.10
1 172.2.52.1 0 msec 0 msec 4 msec
2 172.2.1.203 12 msec 8 msec 0 msec
3 171.9.16.6 4 msec 0 msec 0 msec
4 171.9.4.5 0 msec 4 msec 0 msec
5 171.9.121.34 0 msec 4 msec 4 msec
6 171.9.15.9 120 msec 132 msec 128 msec
7 171.9.15.10 132 msec 128 msec 128 msec
Switch#
The display shows the hop count, IP address of the router, and the round-trip time in milliseconds for
each of the three probes that are sent.
Table 37-1
Traceroute Output Display Characters
Character
Description
*
The probe timed out.
?
Unknown packet type.
A
Administratively unreachable. Usually, this output means that an access list is
blocking traffic.
H
Host unreachable.
N
Network unreachable.
P
Protocol unreachable.
Q
Source quench.
U
Port unreachable.
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Using TDR
To end a trace in progress, enter the escape sequence (Ctrl-^ X by default). Simultaneously press and
release the Ctrl, Shift, and 6 keys, and then press the X key.
Using TDR
•
Understanding TDR, page 12
•
Running TDR and Displaying the Results, page 12
Understanding TDR
You can use the Time Domain Reflector (TDR) feature to diagnose and resolve cabling problems. When
running TDR, a local device sends a signal through a cable and compares the reflected signal to the initial
signal.
TDR can detect these cabling problems:
•
Open, broken, or cut twisted-pair wires—The wires are not connected to the wires from the remote
device.
•
Shorted twisted-pair wires—The wires are touching each other or the wires from the remote device.
For example, a shorted twisted pair can occur if one wire of the twisted pair is soldered to the other
wire.
If one of the twisted-pair wires is open, TDR can find the length at which the wire is open.
Use TDR to diagnose and resolve cabling problems in these situations:
•
Replacing a switch
•
Setting up a wiring closet
•
Troubleshooting a connection between two devices when a link cannot be established or when it is
not operating properly
Running TDR and Displaying the Results
To run TDR, enter the test cable-diagnostics tdr interface interface-id privileged EXEC command:
To display the results, enter the show cable-diagnostics tdr interface interface-id privileged EXEC
command. For a description of the fields in the display, see the command reference for this release.
Note
ITDR is supported only on the copper Ethernet 10/100/1000 ports.
Using Debug Commands
•
Enabling Debugging on a Specific Feature, page 13
•
Enabling All-System Diagnostics, page 13
•
Redirecting Debug and Error Message Output, page 14
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Using Debug Commands
Caution
Note
Because debugging output is assigned high priority in the CPU process, it can render the system
unusable. For this reason, use debug commands only to troubleshoot specific problems or during
troubleshooting sessions with Cisco technical support staff. It is best to use debug commands during
periods of lower network traffic and fewer users. Debugging during these periods decreases the
likelihood that increased debug command processing overhead will affect system use.
For complete syntax and usage information for specific debug commands, see the command reference
for this release.
Enabling Debugging on a Specific Feature
All debug commands are entered in privileged EXEC mode, and most debug commands take no
arguments. For example, beginning in privileged EXEC mode, enter this command to enable the
debugging for all Flex Links backup interface:
Switch# debug backup all
The switch continues to generate output until you enter the no form of the command.
If you enable a debug command and no output appears, consider these possibilities:
•
The switch might not be properly configured to generate the type of traffic that you want to monitor.
Use the show running-config command to check its configuration.
•
Even if the switch is properly configured, it might not generate the type of traffic that you want to
monitor during the particular period that debugging is enabled. Depending on the feature you are
debugging, you can use commands such as the TCP/IP ping command to generate network traffic.
To disable debugging of Flex Links, enter this command in privileged EXEC mode:
Switch# no debug backup all
Alternately, in privileged EXEC mode, you can enter the undebug form of the command:
Switch# undebug backup all
To display the state of each debugging option, enter this command in privileged EXEC mode:
Switch# show debugging
Enabling All-System Diagnostics
Beginning in privileged EXEC mode, enter this command to enable all-system diagnostics:
Switch# debug all
Caution
Because debugging output takes priority over other network traffic, and because the debug all privileged
EXEC command generates more output than any other debug command, it can severely diminish switch
performance or even render it unusable. In virtually all cases, it is best to use more specific debug
commands.
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Using the crashinfo File
The no debug all privileged EXEC command disables all diagnostic output. Using the no debug all
command is a convenient way to ensure that you have not accidentally left any debug commands
enabled.
Redirecting Debug and Error Message Output
By default, the network server sends the output from debug commands and system error messages to the
console. If you use this default, you can use a virtual terminal connection to monitor debug output
instead of connecting to the console port.
Possible destinations include the console, virtual terminals, internal buffer, and UNIX hosts running a
syslog server. The syslog format is compatible with 4.3 Berkeley Standard Distribution (BSD) UNIX
and its derivatives.
Note
Be aware that the debugging destination you use affects system overhead. Logging messages to the
console produces very high overhead, whereas logging messages to a virtual terminal produces less
overhead. Logging messages to a syslog server produces even less, and logging to an internal buffer
produces the least overhead of any method.
For more information about system message logging, see Chapter 24, “Configuring System Message
Logging.”
Using the crashinfo File
The crashinfo file saves information that helps Cisco technical support representatives to debug
problems that caused the Cisco IOS image to fail (crash). The switch writes the crash information to the
console at the time of the failure, and the file is created the next time you boot the Cisco IOS image after
the failure (instead of while the system is failing).
The information in the file includes the Cisco IOS image name and version that failed, a list of the
processor registers, and a stack trace. You can provide this information to the Cisco technical support
representative by using the show tech-support privileged EXEC command.
All crashinfo files are kept in this directory on the flash file system:
flash:/crashinfo/crashinfo_n where n is a sequence number.
Each new crashinfo file that is created uses a sequence number that is larger than any previously existing
sequence number, so the file with the largest sequence number describes the most recent failure. Version
numbers are used instead of a timestamp because the switches do not include a real-time clock. You
cannot change the name of the file that the system will use when it creates the file. However, after the
file is created, you can use the rename privileged EXEC command to rename it, but the contents of the
renamed file will not be displayed by the show tech-support privileged EXEC command. You can delete
crashinfo files by using the delete privileged EXEC command.
You can display the most recent crashinfo file (that is, the file with the highest sequence number at the
end of its filename) by entering the show tech-support privileged EXEC command. You also can access
the file by using any command that can copy or display files, such as the more or the copy privileged
EXEC command.
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Chapter 37
Troubleshooting
Using On-Board Failure Logging
Using On-Board Failure Logging
You can use the on-board-failure logging (OBFL) feature to collect information about the switch. The
information includes uptime, temperature, and voltage information and helps Cisco technical support
representatives to troubleshoot switch problems.
This section has this information:
•
Understanding OBFL, page 15
•
Configuring OBFL, page 15
•
Displaying OBFL Information, page 16
Understanding OBFL
By default, OBFL is enabled and is automatically activated five minutes after the switch boots up. It
collects information about the switch and small form-factor pluggable (SFP) modules. The switch stores
this information in the flash memory:
•
CLI commands—Record of the OBFL CLI commands that are entered on a switch
•
Environmental data—Unique device identifier (UDI) information for a switch and for all the
connected devices: the product identification (PID), the version identification (VID), and the serial
number
•
Message—Record of the hardware-related system messages generated by a switch
•
Temperature—Temperature of a switch
•
Uptime data—Time when a switch starts, the reason the switch restarts, and the length of time the
switch has been running since it last restarted
•
Voltage—System voltages of a switch
You should manually set the system clock, or configure it by using Network Time Protocol (NTP).
When the switch is running, you can retrieve the OBFL data by using the show logging onboard
privileged EXEC commands. If the switch fails, contact your Cisco technical support representative to
find out how to retrieve the data.
When an OBFL-enabled switch is restarted, there is a 10-minute delay before logging of new data
begins.
Configuring OBFL
To enable OBFL, use the hw-module module logging onboard [message level level] global
configuration command. Use the message level level parameter to specify the severity of the
hardware-related messages that the switch generates and stores in the flash memory.
To copy the OBFL data to the local network or a specific file system, use the copy logging onboard
module 1 destination privileged EXEC command.
Caution
We recommend that you keep OBFL enabled and that you do not remove the data stored in the flash
memory.
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Using On-Board Failure Logging
Beginning in privileged EXEC mode, follow these steps to enable and configure OBFL. Note that OBLF
is enabled by default; you need to enable it only if it has been disabled.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
hw-module module [slot-number]
logging onboard [message level]
Enable OBFL on the switch.
You can specify these optional parameters:
•
(Optional) slot-number—The slot number is always 1 and is not
relevant for the switch.
•
(Optional) message level—Specify the severity level of messages to
be generated and stored. The range is from 1 to 7, with 1 being the
most severe.
Step 3
end
Return to privileged EXEC mode.
Step 4
copy logging onboard module
[slot-number] destination
(Optional) Copy the OBFL data to the local network or a specific file
system.
•
(Optional) slot-number—The slot number is always 1 and is not
relevant.
•
destination—See the copy logging onboard module command for
destination options.
Step 5
show logging onboard
Verify your entries.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
To disable OBFL, use the no hw-module module 1 logging onboard [message level] global
configuration command.
To clear all the OBFL data in the flash memory except for the uptime and CLI command information,
use the clear logging onboard privileged EXEC command.
For more information about the commands in this section, see the command reference for this release.
Displaying OBFL Information
To display the OBFL information, use one or more of the privileged EXEC commands in Table 37-2.
Note
Table 37-2
When an OBFL-enabled switch is restarted, there is a 10-minute delay before logging of new data
begins.
Commands for Displaying OBFL Information
Command
Purpose
show logging onboard clilog
Display the OBFL CLI commands that were entered on a switch.
show logging onboard environment
Display the UDI information for a standalone switch and for all the
connected FRU devices: the PID, the VID, and the serial number.
show logging onboard message
Display the hardware-related messages generated by a switch.
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Using On-Board Failure Logging
Table 37-2
Commands for Displaying OBFL Information (continued)
Command
Purpose
show logging onboard temperature
Display the temperature of a switch.
show logging onboard uptime
Display the time when a switch starts, the reason the switch restarts, and
the length of time that the switch has been running since it last restarted.
show logging onboard voltage
Display the system voltages of a switch.
These are examples of output from the show logging onboard commands:
Switch# show logging onboard clilog
-------------------------------------------------------------------------------CLI LOGGING SUMMARY INFORMATION
-------------------------------------------------------------------------------COUNT COMMAND
-------------------------------------------------------------------------------1 hw-module module logging onboard
1 hw-module module logging onboard message level 7
4 show logging onboard
1 show logging onboard message
1 show logging onboard summary
-------------------------------------------------------------------------------Switch# show logging onboard temp
-------------------------------------------------------------------------------TEMPERATURE SUMMARY INFORMATION
-------------------------------------------------------------------------------Number of sensors
: 1
Sampling frequency
: 5 minutes
Maximum time of storage
: 720 minutes
-------------------------------------------------------------------------------Sensor
|
ID | Maximum Temperature 0C
-------------------------------------------------------------------------------System
1
41
-------------------------------------Temp
Sensor ID
0C
1
-------------------------------------No historical data to display
-------------------------------------Switch# show logging onboard uptime
-------------------------------------------------------------------------------UPTIME SUMMARY INFORMATION
-------------------------------------------------------------------------------First customer power on : 03/01/1993 00:06:06
Total uptime
:
0 years 20 weeks
4 days
6 hours 20 minutes
Total downtime
:
0 years
0 weeks
0 days
0 hours
0 minutes
Number of resets
: 90
Number of slot changes : 0
Current reset reason
: 0x0
Current reset timestamp : 03/01/1993 00:05:43
Current slot
: 1
Current uptime
:
0 years
0 weeks
2 days
6 hours
0 minutes
-------------------------------------------------------------------------------Reset |
|
Reason | Count |
-------------------------------------------------------------------------------No historical data to display
--------------------------------------------------------------------------------
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Switch# show logging onboard voltage
-----------------------------------------------------------------------------------------VOLTAGE SUMMARY INFORMATION
-----------------------------------------------------------------------------------------Number of sensors
: 6
Sampling frequency
: 1 minutes
Maximum time of storage
: 720 minutes
-----------------------------------------------------------------------------------------Sensor
|
ID | Maximum Voltage
-----------------------------------------------------------------------------------------12.00V
0
12.567
1.25V
2
1.258
3.30V
3
3.305
2.50V
4
2.517
1.80V
5
1.825
1.50V
6
1.508
-----------------------------------------------------------------------------------------Nominal Range
Sensor ID
-----------------------------------------------------------------------------------------No historical data to display
------------------------------------------------------------------------------------------
For more information about using the commands in Table 37-2 and for examples of OBFL data, see the
command reference for this release.
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