Table Of Contents
distributions-of-statistics-kept
show rtr collection-statistics
show rtr distribution-statistics
snmp-server trap-authentication
statistics-distribution-interval
System Management Commands
This chapter describes the commands used to manage the system and its performance on the network. In general, system or network management falls into the following categories. The commands that perform the tasks in these management categories are described in this chapter unless specified otherwise.
•
Configuration Management
The configuration of network routers determines how the network operates. To manage router configurations, you need to list and compare configuration files on running routers, store configuration files on network servers for shared access, and perform software installations and upgrades. (Configuration management commands required to perform these tasks are described in the "System and Configuration File Load Commands" chapter in the Configuration Fundamentals Command Reference.)
Other configuration management tasks include naming the router, setting time services, configuring for synchronous logging of unsolicited messages and debug output, configuring a router for weighted fair queueing, and configuring SNMP support. Configuration management commands required to perform these tasks are described in this chapter.
•
To manage network faults, you need to discover, isolate, and fix 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 Troubleshooting Internetworking Systems publication. For complete details on all debug commands, see the Debug Command Reference.
•
To manage system performance, you need to monitor and determine response time, error rates, and availability. Once these factors are determined, you can perform load-balancing and modify system parameters to enhance performance. For example, priority queuing allows you to prioritize traffic order. You can configure fast and autonomous switching to improve network throughput, as described in the "Configuring Interfaces" chapter of the Configuration Fundamentals Configuration Guide.
See the Internetwork Design Guide for additional information.
For system management configuration tasks and examples, refer to the chapter entitled "Managing the System" in the Configuration Fundamentals Configuration Guide.
access-enable
To enable the router to create a temporary access list entry in a dynamic access list, use the access-enable EXEC command.
access-enable [host] [timeout minutes]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.1.
This command enables the lock-and-key access feature.
You should always define either an idle timeout (with the timeout keyword in this command) or an absolute timeout (with the timeout keyword in the access-list command). Otherwise, the temporary access list entry will remain, even after the user has terminated his session.
Example
The following example causes the software to create a temporary access list entry and tells the software to enable access only for the host from which the Telnet session originated. If the access list entry is not accessed within 2 minutes, it is deleted.
autocommand access-enable host timeout 2Related Commands
A dagger (†) indicates that the command is documented outside this chapter.
access-list (extended) †
autocommand †access-template
To manually place a temporary access list entry on a router to which you are connected, use the access-template EXEC command.
access-template [access-list-number] [dynamic-name] [source] [destination] [timeout minutes]
Syntax Description
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.1.
This command provides a way to enable the lock-and-key access feature.
You should always define either an idle timeout (with the timeout keyword in this command) or an absolute timeout (with the timeout keyword in the access-list command). Otherwise, the dynamic access list will remain, even after the user has terminated the session.
Example
In the following example, the software enables IP access on incoming packets in which the source address is 172.30.1.129 and the destination address is 172.16.52.12. All other source and destination pairs are discarded.
access-template 101 payroll host 172.30.1.129 host 172.16.52.12 timeout 2Related Commands
A dagger (†) indicates that the command is documented outside this chapter.
access-list (extended) †
autocommand †
clear access-template †alias
To create a command alias, use the alias global configuration command. Use the no form of this command to delete all aliases in a command mode or to delete a specific alias, and to revert to the original command syntax.
alias mode alias-name alias-command-line
no alias mode [alias-name]Syntax Description
mode
Command mode of the original and alias commands. See for a list of options for this argument.
alias-name
Command alias.
alias-command-line
Original command syntax.
Defaults
Default aliases are in EXEC mode as follows:
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
You can use simple words or abbreviations as aliases. The aliases in the Default section are predefined. They can be turned off using the no alias command.
shows the acceptable options for the mode argument in the alias global configuration command.
See the summary of command modes in the "User Interface" chapter in the Configuration Fundamentals Configuration Guide for more information about command modes.
When you use online help, command aliases are indicated by an asterisk (*), as follows:
Router#lo?*lo=logout lock login logoutWhen you use online help, aliases that contain spaces (for example, telnet device.cisco.com 25) are displayed as follows:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# alias exec device-mail telnet device.cisco.com 25Router(config)# endRouter# device-mail?*device-mail="telnet device.cisco.com 25"When you use online help, the alias is expanded and replaced with the original command, as shown in the following example with the td alias:
Router(config)# alias exec td trace deviceRouter(config)# ^ZRouter# t?*td="trace device" telnet terminal test tn3270traceTo list only commands and omit aliases, begin your input line with a space. In the following example, the alias td is not shown, because there is a space before the t? command line.
Router# t?telnet terminal test tn3270 traceAs with commands, you can use online help to display the arguments and keywords that can follow a command alias. In the following example, the alias td is created to represent the command telet device. The /debug and /line switches can be added to telnet device to modify the command:
Router(config)# alias exec td telnet deviceRouter(config)# ^ZRouter# td ?/debug Enable telnet debugging mode/line Enable telnet line mode...whois Whois port<cr>Router# telnet deviceYou must enter the complete syntax for the alias command. Partial syntax for aliases are not accepted. In the following example, the parser does not recognize the command t as indicating the alias td.
bones# t% Ambiguous command: "t"Example
In the following example, the alias fixmyrt is created for the ip route198.92.116.16.
alias exec fixmyrt clear ip route 198.92.116.16Related Command
buckets-of-history-kept
To set the number of history buckets that are kept during the response time reporter probe's lifetime, use the buckets-of-history-kept response time reporter configuration command. Use the no form of this command to return to the default value.
buckets-of-history-kept size
no buckets-of-history-keptSyntax Description
size
Number of history buckets kept during the response time reporter probe's lifetime. The default is 50 buckets.
Default
50 buckets
Command Mode
Response time reporter configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
A response time reporter probe can collect history and capture statistics. By default, history is not collected. When a problem arises where history is useful (for example, a large number of timeouts are occurring), you can configure the lives-of-history-kept response time reporter configuration command to collect history. You can optionally adjust the buckets-of-history-kept, filter-for-history, and sample-of-history-kept response time reporter configuration commands.
When the number of buckets reaches the size specified, no further history for this life is stored.
Note
If history is collected, each bucket contains one or more history entries from the probe. When the probe type is pathEcho, an entry is created for each hop along the path that the probe takes to reach its destination. The type of entry stored in the history table is controlled by the filter-for-history response time reporter configuration command. The total number of entries stored in the history table is controlled by the combination of samples-of-history-kept, buckets-of-history-kept, and lives-of-history-kept response time reporter configuration commands.
Each time the probe starts a response time reporter operation, a new bucket is created until the number of history buckets matches the specified size or the probe's lifetime expires. History buckets do not wrap. The probe's lifetime is defined by the rtr schedule global configuration command. The probe starts a response time reporter operation based on the seconds specified by the frequency response time reporter configuration command.
Example
In the following example, probe 1 is configured to keep 25 history buckets during the probe's lifetime:
rtr 1type echo protocol ipIcmpEcho 172.16.161.21buckets-of-history-kept 25lives-of-history-kept 1Related Commands
filter-for-history
lives-of-history-kept
rtr
rtr schedule
samples-of-history-keptbuffers
Use the buffers global configuration command to make adjustments to initial buffer pool settings and to the limits at which temporary buffers are created and destroyed. Use the no form of this command to return the buffers to their default size.
buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free
| min-free | initial} number
no buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free
| min-free | initial} numberSyntax Description
Default
The default number of buffers in a pool is determined by the hardware configuration and can be displayed with the EXEC show buffers command.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Normally you need not adjust these parameters; do so only after consulting with technical support personnel. Improper settings can adversely impact system performance.
You cannot configure FDDI buffers.
Examples of Public Buffer Pool Tuning
In the following example, the system will try to keep at least 50 small buffers free:
buffers small min-free 50In the following example, the permanent buffer pool allocation for big buffers is increased to 200:
buffers big permanent 200Example of Interface Buffer Pool Tuning
A general guideline is to display buffers with the show buffers command, observe which buffer pool is depleted, and increase that one.
In the following example, the permanent Ethernet 0 interface buffer pool on a Cisco 4000 is increased to 96 because the Ethernet 0 buffer pool is depleted:
buffers ethernet 0 permanent 96Related Commands
buffers huge size
Use the buffers huge size global configuration command to dynamically resize all huge buffers to the value you specify. Use the no form of this command to restore the default buffer values.
buffers huge size number
no buffers huge size numberSyntax Description
Default
18024 bytes
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use only after consulting with technical support personnel. The buffer size cannot be lowered below the default.
Example
In the following example, the system will resize huge buffers to 20000 bytes:
buffers huge size 20000Related Commands
calendar set
To set the system calendar for a Cisco 7000 series, Cisco 7200 series, or Cisco 4500 series, use the calendar set EXEC command.
calendar set hh:mm:ss day month year
calendar set hh:mm:ss month day yearSyntax Description
hh:mm:ss
Current time in hours (military format), minutes, and seconds.
day
Current day (by date) in the month.
month
Current month (by name).
year
Current year (no abbreviation).
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
After you set the Cisco 7000, Cisco 7200, or Cisco 4500 calendar, the system clock will be automatically set when the system is restarted or when the clock read-calendar EXEC command is issued. The calendar maintains its accuracy, even after a power failure or system reboot has occurred. The time specified in this command is relative to the configured time zone.
Example
In the following example, the system calendar is manually set to 1:32 p.m. on July 23, 1993:
calendar set 13:32:00 23 July 1993Related Commands
clock read-calendar
clock set
clock summer-time
clock timezone
clock update-calendarcdp enable
To enable Cisco Discovery Protocol (CDP) on an interface, use the cdp enable interface configuration command. Use the no form of this command to disable CDP on an interface.
cdp enable
no cdp enableSyntax Description
This command has no arguments or keywords.
Default
Enabled at the global level and on all supported interfaces.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CDP is enabled by default at the global level and on each supported interface in order to send or receive CDP information. However, some interfaces, such as ATM interfaces, do not support CDP.
Note
Example
In the following example, CDP is enabled on Ethernet interface 0:
interface ethernet 0cdp enableRelated Command
cdp holdtime
To specify the amount of time the receiving device should hold a CDP packet from your router before discarding it, use the cdp holdtime global configuration command. Use the no form of this command to revert to the default setting.
cdp holdtime seconds
no cdp holdtimeSyntax Description
Default
180 seconds
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CDP packets are sent with time-to-live, or hold time, that is nonzero after an interface is enabled and a hold time of 0 immediately before an interface is idled down.
The CDP hold time must be set to a higher number of seconds than the time between CDP transmissions, which is set using the cdp timer command.
Example
In the following example, the CDP packets being sent from your router should be held by the receiving device for 60 seconds before being discarded. You might want to set the hold time lower than the default setting of 180 seconds if information about your router changes often and you want the receiving devices to purge this information more quickly.
cdp holdtime 60Related Commands
cdp run
To enable CDP, use the cdp run global configuration command. Use the no form of this command to disable CDP.
cdp run
no cdp runSyntax Description
This command has no arguments or keywords.
Default
Enabled
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CDP is enabled on your router by default, which means the Cisco IOS software will receive CDP information. CDP also is enabled on supported interfaces by default. To disable CDP on an interface, use the no cdp enable interface configuration command.
Note
Example
In the following example, CDP is disabled:
no cdp runRelated Command
cdp timer
To specify how often the Cisco IOS software sends CDP updates, use the cdp timer global configuration command. Use the no form of this command to revert to the default setting.
cdp timer seconds
no cdp timerSyntax Description
Default
60 seconds
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
The trade-off with sending more frequent transmissions is providing up-to-date information versus using bandwidth more often.
Note
Example
In the following example, CDP updates are sent every 80 seconds, less frequently than the default setting of 60 seconds. You might want to make this change if you are concerned about preserving bandwidth.
cdp timer 80Related Commands
clear cdp counters
To reset CDP traffic counters to zero (0), use the clear cdp counters privileged EXEC command.
clear cdp counters
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Example
In the following example, the CDP counters have been cleared. The show cdp traffic output shows that all of the traffic counters have been reset to zero (0).
Router# clear cdp countersRouter# show cdp trafficCDP counters:Packets output: 0, Input: 0Hdr syntax: 0, Chksum error: 0, Encaps failed: 0No memory: 0, Invalid packet: 0, Fragmented: 0Related Commands
clear cdp table
show cdp trafficclear cdp table
To clear the table that contains CDP information about neighbors, use the clear cdp table privileged EXEC command.
clear cdp table
Syntax Description
This command has no arguments or keywords.
Command Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
Example
In the following example, the CDP table is cleared. The output of the show cdp neighbors command shows that all information has been deleted from the table.
Router# clear cdp tableCDP-AD: Deleted table entry for neon.cisco.com, interface Ethernet0CDP-AD: Deleted table entry for neon.cisco.com, interface Serial0Router# show cdp neighborsCapability Codes: R - Router, T - Trans Bridge, B - Source Route BridgeS - Switch, H - Host, I - IGMPDevice ID Local Intrfce Holdtme Capability Platform Port IDRelated Commands
clear cdp counters
show cdp neighborsclear 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 Mode
Privileged EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
Example
In the following example, the logging buffer is cleared.
Router# clear loggingClear logging buffer [confirm]Router#Related Commands
clock calendar-valid
To configure the Cisco 7000 series or the Cisco 4500 as a time source for a network based on its calendar, use the clock calendar-valid global configuration command. Use the no form of this command to set the Cisco IOS software so that the calendar is not an authoritative time source.
clock calendar-valid
no clock calendar-validSyntax Description
This command has no arguments or keywords.
Default
Neither the Cisco 7000 nor the Cisco 4500 are not configured as a time source.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use this command if no outside time source is available.
Example
In the following example, the Cisco 7000 is configured as the time source for a network based on its calendar:
clock calendar-validRelated Commands
A dagger (†) indicates that the command is documented outside this chapter.
ntp master
vines time use-system †clock read-calendar
To manually read the calendar into either the Cisco 7000 series, Cisco 7200 series, or Cisco 4500 series clock, use the clock read-calendar EXEC command.
clock read-calendar
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
When either the Cisco 7000 series, Cisco 7200 series, or Cisco 4500 series calendar is rebooted, the calendar is automatically read into the system clock. However, you may use this command to manually read the calendar setting into the system clock. This command is useful if the calendar set command has been used to change the setting of the calendar.
Example
In the following example, the system clock is configured to set its date and time by the calendar setting:
clock read-calendarRelated Commands
calendar set
clock set
clock update-calendar
ntp update-calendarclock set
To manually set the system clock, use the clock set EXEC command.
clock set hh:mm:ss day month year
clock set hh:mm:ss month day yearSyntax Description
hh:mm:ss
Current time in hours (military format), minutes, and seconds.
day
Current day (by date) in the month.
month
Current month (by name).
year
Current year (no abbreviation).
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Generally, if the system is synchronized by a valid outside timing mechanism, such as an NTP or VINES clock source, or if you have a Cisco 7000 or Cisco 7200 with calendar capability, you do not need to set the system clock. Use this command if no other time sources are available. The time specified in this command is relative to the configured time zone.
Example
In the following example, the system clock is manually set to 1:32 p.m. on July 23, 1993:
clock set 13:32:00 23 July 1993Related Commands
calendar set
clock read-calendar
clock summer-time
clock timezoneclock summer-time
To configure the system to automatically switch to summer time (daylight savings time), use one of the formats of the clock summer-time configuration command. Use the no form of this command to configure the Cisco IOS software not to automatically switch to summer time.
clock summer-time zone recurring [week day month hh:mm week day month hh:mm [offset]]
clock summer-time zone date date month year hh:mm date month year hh:mm [offset]
clock summer-time zone date month date year hh:mm month date year hh:mm [offset]
no clock summer-timeSyntax Description
Default
Summer time is disabled. If clock summer-time zone recurring is specified without parameters, the summer time rules default to United States rules. Default of offset is 60.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Use this command if you want to automatically switch to summer time (for display purposes only). Use the recurring form of the command if the local summer time rules are of this form. Use the date form to specify a start and end date for summer time if you cannot use the first form.
In both forms of the command, the first part of the command specifies when summer time begins, and the second part specifies when it ends. All times are relative to the local time zone. The start time is relative to standard time. The end time is relative to summer time. If the starting month is after the ending month, the system assumes that you are in the Southern Hemisphere.
Examples
In the following example, summer time starts on the first Sunday in April at 02:00 and ends on the last Sunday in October at 02:00:
clock summer-time PDT recurring 1 Sunday April 2:00 last Sunday October 2:00If you live in a place where summer time does not follow the pattern in the first example, you could set it to start on October 12, 1993 at 02:00, and end on April 28, 1994 at 02:00, with the following example:
clock summer-time date 12 October 1993 2:00 28 April 1994 2:00Related Commands
clock timezone
To set the time zone for display purposes, use the clock timezone global configuration command. To set the time to Coordinated Universal Time (UTC), use the no form of this command.
clock timezone zone hours [minutes]
no clock timezoneSyntax Description
zone
Name of the time zone to be displayed when standard time is in effect.
hours
Hours offset from UTC.
minutes
(Optional) Minutes offset from UTC.
Default
UTC
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
The system internally keeps time in UTC, so this command is used only for display purposes and when the time is manually set.
Example
In the following example, the timezone is set to Pacific Standard Time and is offset 8 hours behind UTC:
clock timezone PST -8Related Commands
calendar set
clock set
clock summer-time
show clockclock update-calendar
To set the Cisco 7000, Cisco 7200, or Cisco 4500 calendar from the system clock, use the clock update-calendar EXEC command.
clock update-calendar
Syntax Description
This command has no arguments or keywords.
Command Mode
EXEC
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
If the system clock and calendar are not synchronized, and the system clock is more accurate, use this command to update the Cisco 7000 series, Cisco 7200 series, or Cisco 4500 series calendar to the correct date and time.
Example
In the following example, the current time is copied from the system clock to the Cisco 7000 calendar:
clock update-calendarRelated Commands
clock read-calendar
ntp update-calendarcustom-queue-list
To assign a custom queue list to an interface, use the custom-queue-list interface configuration command. To remove a specific list or all list assignments, use the no form of the command.
custom-queue-list list
no custom-queue-list [list]Syntax Description
Default
No custom queue list is assigned.
Command Mode
Interface configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.0.
Note
Only one queue list can be assigned per interface. Use this command in place of the priority-list command (not in addition to it). Custom queuing allows a fairness not provided with priority queuing. With custom queuing, you can control the interfaces' available bandwidth when it is unable to accommodate the aggregate traffic enqueued. Associated with each output queue is a configurable byte count, which specifies how many bytes of data should be delivered from the current queue by the system before the system moves on to the next queue. When a particular queue is being processed, packets are sent until the number of bytes sent exceeds the queue byte count or until the queue is empty.
Use the show queuing custom and show interface commands to display the current status of the custom output queues.
Example
In the following example, custom queue list number 3 is assigned to serial interface 0:
interface serial 0custom-queue-list 3Related Commands
queue-list default
queue-list interface
queue-list protocol
queue-list queue byte-count
queue-list queue limitdistributions-of-statistics-kept
To set the number of statistic distributions kept per hop during the response time reporter probe's lifetime, use the distributions-of-statistics-kept response time reporter configuration command. Use the no form of this command to return to the default value.
distributions-of-statistics-kept size
no distributions-of-statistics-keptSyntax Description
Default
1 distribution
Command Mode
Response time reporter configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.2.
In most situations, you do not need to change the statistic distribution size for the response time reporter. Only change the size when distributions are needed (for example, when performing statistical modeling of your network).
Note
When the number of distributions reaches the size specified, no further distribution information is stored.
Example
In the following example, the distribution is set to 5 and the distribution interval is set to 10 ms. This means that the first distribution will contain statistics from 0 to 9 ms, the second distribution will contain statistics from 10 to 19 ms, the third distribution will contain statistics from 20 to 29 ms, the fourth distribution will contain statistics from 30 to 39 ms, and the fifth distribution will contain statistics from 40 ms to infinity.
rtr 1type echo protocol ipIcmpEcho 172.16.161.21distribution-of-statistics-kept 5statistics-distribution-interval 10Related Commands
hops-of-statistics-kept
hours-of-statistics-kept
paths-of-statistics-kept
rtr
statistics-distribution-intervaldownward-compatible-config
To generate a configuration that is compatible with an earlier Cisco IOS Release, use the downward-compatible-config global configuration command. To remove this feature, use the no form of this command.
downward-compatible-config version
no downward-compatible-configSyntax Description
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 11.1.
In Cisco IOS Release 10.3, IP access lists changed format. Use this command to regenerate a configuration in a format prior to Release 10.3 if you are going to downgrade from a Release 10.3 or later to an earlier release. The earliest release this command accepts is 10.2.
When this command is configured, the router attempts to generate a configuration that is compatible with the specified version. Currently, this command affects only IP access lists.
Under some circumstances, the software might not be able to generate a fully backward-compatible configuration. In such a case, the software issues a warning message.
Example
In the following example, the router attempts to generate a configuration file compatible with Cisco IOS Release 10.2:
downward-compatible-config 10.2Related Commands
A dagger (†) indicates that the command is documented outside this chapter.
access-list (extended) †
access-list (standard) †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-fileSyntax Description
Default
The core file is named hostname-core, where hostname is the name of the router.
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CautionUse the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps.
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.
Example
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
exception memory
exception protocol
ip ftp password
ip ftp usernameexception 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 dumpSyntax Description
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CautionUse the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps.
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).
Example
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 core-file
exception memory
exception protocol
ip ftp password
ip ftp username
ip rcmd remote-usernameexception 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.
Default
Disabled
Command Mode
Global configuration
Usage Guidelines
This command first appeared in Cisco IOS Release 10.3.
CautionUse the exception commands only under the direction of a technical support representative. Creating a core dump while the router is functioning in a network can disrupt network operation. The resulting binary file, which is very large, must be transferred to a TFTP, FTP, or rcp server and subsequently interpreted by technical personnel who have access to source code and detailed memory maps.
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 file. If the exception dump command is not configured, the router reloads without generating a core dump.
Example
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 core-file
exception dump
exception protocol
ip ftp password
ip ftp usernameexception 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 protocolSyntax Description
ftp
Use FTP for core dumps.
rcp
Use rcp for core dumps.
tftp
Use TFTP for core dumps. This is the default.
Default
TFTP
