- Cisco IOS Configuration Fundamentals Command Reference, Release 12.1
Table Of Contents
show c2600 (Cisco 2600 series)
show c7200 (Cisco 7200 series)
show controllers (line card image)
show gt64010 (Cisco 7200 series)
Troubleshooting Commands
This chapter describes the commands used to troubleshoot your router. To troubleshoot, you need to discover, isolate, and resolve the problems. You can discover problems with the system's monitoring commands, isolate problems with the system's test commands, and resolve problems with other commands, including debug.
This chapter describes general fault management commands. For detailed troubleshooting procedures and a variety of scenarios, see the Cisco IOS Internetwork Troubleshooting Guide publication. For complete details on all debug commands, see the Cisco IOS Debug Command Reference.
For troubleshooting tasks and examples, refer to the "Troubleshooting the Router" chapter in the Cisco IOS Configuration Fundamentals Configuration Guide.
attach
To connect to a specific line card for the purpose of executing monitoring and maintenance commands on that line card only, use the attach privileged EXEC command. To exit from the Cisco IOS software image on the line card and return to the Cisco IOS image on the GRP card, use the exit command.
attach slot-number
Syntax Description
Defaults
None
Command Modes
Privileged EXEC
Command History
11.2 GS
This command was added to support the Cisco 12000 series Gigabit Switch Routers.
Usage Guidelines
You must first use the attach privileged EXEC command to access the Cisco IOS software image on a line card before using line card-specific show commands. Alternatively, you can use the execute-on privileged EXEC command to execute a show command on a specific line card.
After you connect to the Cisco IOS image on the line card using the attach command, the prompt changes to "LC-Slotx#," where x is the slot number of the line card.
The commands executed on the line card use the Cisco IOS image on that line card.
You can also use the execute-on slot privileged EXEC command to execute commands on one or all line cards.
Note
Do not execute the config command from the Cisco IOS software image on the line card.
Examples
The following example connects to the Cisco IOS image running on the line card in slot 9, gets a list of valid show commands, and returns the Cisco IOS image running on the GRP:
Router# attach 9Entering Console for 4 Port Packet Over SONET OC-3c/STM-1 in Slot: 9Type exit to end this sessionPress RETURN to get started!LC-Slot9# show ?cef Cisco Express Forwardingclock Display the system clockcontext Show context information about recent crash(s)history Display the session command historyhosts IP domain-name, lookup style, nameservers, and host tableipc Interprocess communications commandslocation Display the system locationsessions Information about Telnet connectionsterminal Display terminal configuration parametersusers Display information about terminal linesversion System hardware and software statusLC-Slot9# exitDisconnecting from slot 9.Connection Duration: 00:01:04Router#
Note
Related Commands
clear logging
To clear messages from the logging buffer, use the clear logging privileged EXEC command.
clear logging
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following example clears the logging buffer:
Router# clear loggingClear logging buffer [confirm]Router#Related Commands
logging buffered
Logs messages to an internal buffer.
show logging
Displays the state of logging (syslog).
diag
To perform field diagnostics on a line card, on the Gigabit Route Processor (GRP), on the Switch Fabric Cards (SFC), and on the Clock Scheduler Card (CSC) in Cisco 12000 series Gigabit Switch Routers, use the diag privileged EXEC command. To disable field diagnostics on a line card, use the no form of this command.
diag slot-number [halt | previous | post | verbose [wait] | wait]
no diag slot-number
Syntax Description
Defaults
No field diagnostics tests are performed on the line card.
Command Modes
Privileged EXEC
Command History
11.2 GS
This command was added to support the Cisco 12000 series Gigabit Switch Routers.
Usage Guidelines
The diag command must be executed from the GRP main console port.
Perform diagnostics on the CSC only if a redundant CSC is in the router.
Diagnostics will stop and ask you for confirmation before altering the router's configuration. For example, running diagnostics on a SFC or CSC will cause the fabric to go from full bandwidth to one quarter bandwidth. Bandwidth is not affected by GRP or line card diagnostics.
The field diagnostic software image is bundled with the Cisco IOS software and is downloaded automatically from the GRP to the target line card prior to testing.
Caution
In normal mode, if a test fails, the title of the failed test is displayed on the console. However, not all tests that are performed are displayed. To view all the tests that are performed, use the verbose keyword.
After all diagnostic tests are completed on the line card, a PASSED or TEST FAILURE message is displayed. If the line card sends a PASSED message, the Cisco IOS software image on the line card is automatically reloaded unless the wait keyword is specified. If the line card sends a TEST FAILURE message, the Cisco IOS software image on the line card is not automatically reloaded.
If you want to reload the line card after it fails diagnostic testing, use the microcode reload slot global configuration command.
Note
If the line card fails the test, the line card is defective and should be replaced. In future releases this might not be the case because DRAM and SDRAM SIMM modules might be field replaceable units. For example, if the DRAM test failed you might only need to replace the DRAM on the line card.
For more information, refer to the Cisco 12000 series installation and configuration guides.
Examples
The following example shows the output when field diagnostics are performed on the line card in slot 3. After the line card passes all field diagnostic tests, the Cisco IOS software is automatically reloaded on the card. Before starting the diagnostic tests, you must confirm the request to perform these tests on the line card because all activity on the line card is halted. The total/indiv. timeout set to 600/220 sec. message indicates that 600 seconds are allowed to perform all field diagnostics tests, and that no single test should exceed 220 seconds to complete.
Router# diag 3Running Diags will halt ALL activity on the requested slot. [confirm]Router#Launching a Field Diagnostic for slot 3Running DIAG config checkRUNNING DIAG download to slot 3 (timeout set to 400 sec.)sending cmd FDIAG-DO ALL to fdiag in slot 3(total/indiv. timeout set to 600/220 sec.)Field Diagnostic ****PASSED**** for slot 3Field Diag eeprom values: run 159 fial mode 0 (PASS) slot 3last test failed was 0, error code 0sending SHUTDOWN FDIAG_QUIT to fdiag in slot 3Board will reload...Router#The following example shows the output when field diagnostics are performed on the line card in slot 3 in verbose mode:
Router# diag 3 verboseRunning Diags will halt ALL activity on the requested slot. [confirm]Router#Launching a Field Diagnostic for slot 3Running DIAG config checkRUNNING DIAG download to slot 3 (timeout set to 400 sec.)sending cmd FDIAG-DO ALL to fdiag in slot 3(total/indiv. timeout set to 600/220 sec.)FDIAG_STAT_IN_PROGRESS: test #1 R5K Internal CacheFDIAG_STAT_PASS test_num 1FDIAG_STAT_IN_PROGRESS: test #2 Sunblock OrderingFDIAG_STAT_PASS test_num 2FDIAG_STAT_IN_PROGRESS: test #3 Dram DatapinsFDIAG_STAT_PASS test_num 3...Field Diags: FDIAG_STAT_DONEField Diagnostic ****PASSED**** for slot 3Field Diag eeprom values: run 159 fial mode 0 (PASS) slot 3last test failed was 0, error code 0sending SHUTDOWN FDIAG_QUIT to fdiag in slot 3Board will reload...Router#Related Commands
exception core-file
To specify the name of the core dump file, use the exception core-file global configuration command. To return to the default core filename, use the no form of this command.
exception core-file name
no exception core-file
Syntax Description
Defaults
The core file is named hostname-core, where hostname is the name of the router.
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
Examples
The following example configures a router to use FTP to dump a core file named dumpfile to the FTP server at 172.17.92.2 when it crashes:
ip ftp username redip ftp password blueexception protocol ftpexception dump 172.17.92.2exception core-file dumpfileRelated Commands
exception dump
To configure the router to dump a core file to a particular server when the router crashes, use the exception dump global configuration command. To disable core dumps, use the no form of this command.
exception dump ip-address
no exception dump
Syntax Description
Defaults
Disabled
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
The core dump is written to a file named hostname-core on your server, where hostname is the name of the router. You can change the name of the core file by configuring the exception core-file command.
This procedure can fail for certain types of system crashes. However, if successful, the core dump file will be the size of the memory available on the processor (for example, 16 MB for a CSC/4).
Examples
The following example configures a router to use FTP to dump a core file to the FTP server at 172.17.92.2 when it crashes:
ip ftp username redip ftp password blueexception protocol ftpexception dump 172.17.92.2Related Commands
exception linecard
To enable storing of crash information for a line card and optionally specify the type and amount of information stored, use the exception linecard global configuration command. To disable the storing of crash information for the line card, use the no form of this command.
exception linecard {all | slot slot-number} [corefile filename | main-memory size [k | m] | queue-ram size [k | m] | rx-buffer size [k | m] | sqe-register-rx | sqe-register-tx | tx-buffer size [k | m]]
no exception linecard
Syntax Description
Defaults
No crash information is stored for the line card.
If enabled with no options, the default is to store 256 MB of main memory.
Command Modes
Global configuration
Command History
Usage Guidelines
This command is currently supported only on Cisco 12000 series Gigabit Switch Routers.
Use the exception linecard global configuration command only when directed by a technical support representative and only enable options that the technical support representative requests you to enable. Technical support representatives need to be able to look at the crash information from the line card to troubleshoot serious problems on the line card. The crash information contains all the line card memory information including the main memory and transmit and receive buffer information.
Caution
Examples
The following example enables the storing of crash information for line card 8. By default, 256 MB of main memory is stored.
exception linecard slot 8endexception memory
To cause the router to create a core dump and reboot when certain memory size parameters are violated, use the exception memory global configuration command. To disable the rebooting and core dump, use the no form of this command.
exception memory {fragment size | minimum size}
no exception memory {fragment | minimum}
Syntax Description
fragment size
The minimum contiguous block of memory in the free pool, in bytes.
minimum size
The minimum size of the free memory pool, in bytes.
Defaults
Disabled
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
This command is useful to troubleshoot memory leaks.
The size is checked every 60 seconds. If you enter a size that is greater than the free memory, a core dump and router reload is generated after 60 seconds.
The exception dump command must be configured in order to generate a core dump file. If the exception dump command is not configured, the router reloads without generating a core dump.
Examples
The following example configures the router to monitor the free memory. If the amount of free memory falls below 250,000 bytes, the router will dump the core file and reload.
exception dump 131.108.92.2exception core-file memory.overrunexception memory minimum 250000Related Commands
exception protocol
To configure the protocol used for core dumps, use the exception protocol global configuration command. To configure the router to use the default protocol, use the no form of this command.
exception protocol {ftp | rcp | tftp}
no exception protocol
Syntax Description
ftp
Use FTP for core dumps.
rcp
Use rcp for core dumps.
tftp
Use TFTP for core dumps. This is the default.
Defaults
TFTP
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
If you use TFTP to dump the core file to a server, the router will only dump the first 16 MB of the core file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
Examples
The following example configures a router to use FTP to dump a core file to the FTP server at 172.17.92.2 when it crashes:
ip ftp username redip ftp password blueexception protocol ftpexception dump 172.17.92.2Related Commands
exception region-size
To specify the size of the region for exception-time memory pool, use the exception region-size global configuration command. To use the default region size, use the no form of this command.
exception region-size size
no exception region-size
Syntax Description
Defaults
16384 bytes.
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
The exception region-size command is used to define a small amount of memory to serve as a fallback pool when the processor memory pool is marked corrupt. The exception memory command must be used to allocate memory to perform a core dump.
Examples
The following example sets the region size at 1024:
Router# exception region-size 1024Related Commands
exception spurious-interrupt
To configure the router to create a core dump and reload after a specified number of spurious interrupts, use the exception spurious-interrupt command global configuration command. To disable the core dump and reload, use the no form of this command.
exception spurious-interrupt [number]
no exception spurious-interrupt
Syntax Description
number
Number from 1 to 4294967295 that indicates the maximum number of spurious interrupts to include in the core dump before reloading.
Defaults
Disabled
Command Modes
Global configuration
Command History
Usage Guidelines
Caution
If you use TFTP to dump the core dump file to a server, the router will only dump the first 16 MB of the file. If the router's memory is larger than 16 MB, the whole core file will not be copied to the server. Therefore, use rcp or FTP to dump the core file.
Examples
The following example configures a router to create a core dump with a limit of 2 spurious interrupts:
Router# exception spurious-interrupt 2Related Commands
execute-on
To execute commands on a line card, use the execute-on privileged EXEC command.
execute-on {slot slot-number | all | master} command
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
Use this command to execute a command on one or all line cards to monitor and maintain information on one or more line cards (for example, a line card in a specified slot on a dial shelf). This allows you to issue commands remotely; that is, to issue commands without having to log on to the line card directly. The all form of the command allows you to issue commands to all the line cards without having to log on to each on in turn.
Though this command does not have a no form, note that it is possible to use the no form of the remotely executed commands used in this command.
Note
Cisco 12000 GSR Guidelines and Restrictions
You can use the execute-on privileged EXEC command only from Cisco IOS software running on the GRP card.
Timesaver
Cisco AS5800 Guidelines and Restrictions
The purpose of the command is to conveniently enable certain commands to be remotely executed on the dial shelf cards from the router without connecting to each line card. This is the recommended procedure, because it avoids the possibility of adversely affecting a good configuration of a line card in the process. The command execute-on does not give access to every IOS command available on the Cisco AS5800. In general, the purpose of the execute-on command is to provide access to statistical reports from line cards without directly connecting to the dial shelf line cards.
Note
Using this command makes it possible to accumulate inputs for inclusion in the show tech-support command.
The master form of the command can run a designated command remotely on the router from the DSC card. However, using the console on the DSC is not recommended. It is used for technical support troubleshooting only.
The show tech-support command for each dial shelf card is bundled into the router shelf's show tech-support command via the execute-on facility.
The execute-on command also support interactive commands such as:
router: execute-on slave slot slot pingThe execute-on command has the same limitations/restrictions as a vty telnet client has, that is, it cannot reload DSC using:
router: execute-on slave slot slot reloadYou can use the execute-on command to enable remote execution of the following partial list of commands:
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Examples
The following example executes the show controllers command on the line card in slot 4 of a Cisco 12000 series GSR:
Router# execute-on slot 4 show controllers========= Line Card (Slot 4) =======Interface POS0Hardware is BFLC POSlcpos_instance struct 6033A6E0RX POS ASIC addr space 12000000TX POS ASIC addr space 12000100SUNI framer addr space 12000400SUNI rsop intr status 00CRC16 enabled, HDLC enc, int clockno loopInterface POS1Hardware is BFLC POSlcpos_instance struct 6033CEC0RX POS ASIC addr space 12000000TX POS ASIC addr space 12000100SUNI framer addr space 12000600SUNI rsop intr status 00CRC32 enabled, HDLC enc, int clockno loopInterface POS2Hardware is BFLC POSlcpos_instance struct 6033F6A0RX POS ASIC addr space 12000000TX POS ASIC addr space 12000100SUNI framer addr space 12000800SUNI rsop intr status 00CRC32 enabled, HDLC enc, int clockno loopInterface POS3Hardware is BFLC POSlcpos_instance struct 60341E80RX POS ASIC addr space 12000000TX POS ASIC addr space 12000100SUNI framer addr space 12000A00SUNI rsop intr status 00CRC32 enabled, HDLC enc, ext clockno loopRouter#Related Commands
attach
Connects you to a specific line card for the purpose of executing commands using the Cisco IOS software image on that line card.
logging
To log messages to a syslog server host, use the logging global configuration command. The no form of this command deletes the syslog server with the specified address from the list of syslogs.
logging host
no logging host
Syntax Description
Defaults
No messages are logged to a syslog server host.
Command Modes
Global configuration
Command History
Usage Guidelines
This command identifies a syslog server host to receive logging messages. By issuing this command more than once, you build a list of syslog servers that receive logging messages.
Examples
The following example logs messages to a host named johnson:
logging johnsonRelated Commands
logging buffered
To limit messages logged to an internal buffer based on severity, use the logging buffered global configuration command. The no form of this command cancels the use of the buffer. The default form of this command returns the buffer size to the default size.
logging buffered [size | level]
no logging buffered
default logging buffered
Syntax Description
size
(Optional) Size of the buffer from 4096 to 4294967295 bytes. The default size varies by platform.
level
Limits the logging of messages to the buffer to a specified level. You can enter the level number or level name. See Table 63 for a list of the level arguments.
Defaults
For most platforms, the Cisco IOS software logs messages to the internal buffer.
Command Modes
Global configuration
Command History
10.0
This command was introduced.
11.1(17)T
The command syntax was changed to include the level argument.
Usage Guidelines
This command copies logging messages to an internal buffer. The buffer is circular in nature, so newer messages overwrite older messages after the buffer is filled.
Specifying a level causes messages at that level and numerically lower levels to be logged in an internal buffer. See Table 63 for a list of level arguments.
Do not make the buffer size too large because the router could run out of memory for other tasks. You can use the show memory EXEC command to view the free processor memory on the router; however, this is the maximum available and should not be approached. The command default logging buffered resets the buffer size to the default for the platform.
To display the messages that are logged in the buffer, use the EXEC command show logging. The first message displayed is the oldest message in the buffer.
The EXEC command show logging displays the addresses and levels associated with the current logging setup, as well as any other logging statistics.
The following example enables logging to an internal buffer:
logging bufferedRelated Commands
clear logging
Clears messages from the logging buffer.
show logging
Displays the state of logging (syslog).
logging console
To limit messages logged to the console based on severity, use the logging console global configuration command. The no form of this command disables logging to the console terminal.
logging console level
no logging console
Syntax Description
level
Limits the logging of messages displayed on the console terminal to a specified level. You can enter the level number or level name. See Table 64 for a list of the level arguments.
Defaults
debugging
Command Modes
Global configuration
Command History
Usage Guidelines
Specifying a level causes messages at that level and numerically lower levels to be displayed at the console terminal.
The EXEC command show logging displays the addresses and levels associated with the current logging setup, as well as any other logging statistics. Table 64 shows descriptions for the various logging levels.
