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Cisco IOS Configuration Fundamentals and Network Management Command Reference, Release 12.3
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Introduction
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CFR Commands: absolute -- clock timezone
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CFR Commands: clock update-calendar -- escape-character
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CFR Commands: exception core-file -- ip ftp passive
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CFR Commands: ip ftp password -- lsr-path
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CFR Commands: memory sanity -- periodic
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CFR Commands: ping -- service sequence numbers
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CFR Commands: service slave-log -- show
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CFR Commands: show context -- show ip http server
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CFR Commands: show kron schedule -- show rtr enhanced-history
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12.3 CF CR Commands: show rtr distributions-statistics -- snmp-server enable informs
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CFR Commands: snmp-server enable traps -- statistics-distribution-interval
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CFR Commands: stopbits -- ttl ip
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CFR Commands: type dhcp - xsm vdm
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CFR Appendix: ASCII Character Set and Hex Values
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Table Of Contents
Configuration Fundamentals and Network Management Commands
Configuration Fundamentals and Network Management Commands
absolute
To specify an absolute time when a time range is in effect, use the absolute command in time-range configuration mode. To remove the time limitation, use the no form of this command.
absolute [start time date] [end time date]
no absolute
Syntax Description
Defaults
There is no absolute time when the time range is in effect.
Command Modes
Time-range configuration
Command History
Usage Guidelines
Time ranges are used by IP and Internetwork Packet Exchange (IPX) extended access lists. For more information on using these functions, see the Cisco IOS IP Configuration Guide and the Cisco IOS AppleTalk and Novell IPX Configuration Guide. Time ranges are applied to the permit or deny statements found in these access lists.
The absolute command is one way to specify when a time range is in effect. Another way is to specify a periodic length of time with the periodic command. Use either of these commands after the time-range command, which enables time-range configuration mode and specifies a name for the time range. Only one absolute entry is allowed per time-range command.
If a time-range command has both absolute and periodic values specified, then the periodic items are evaluated only after the absolute start time is reached, and are not further evaluated after the absolute end time is reached.
Note
All time specifications are interpreted as local time. To ensure that the time range entries take effect at the desired times, the software clock should be synchronized using the Network Time Protocol (NTP), or some other authoritative time source. For more information, refer to the "Performing Basic System Management" chapter of the Cisco IOS Configuration Fundamentals Configuration Guide.
Examples
The following example configures an access list named northeast, which references a time range named xyz. The access list and time range together permit traffic on Ethernet interface 0 starting at noon on January 1, 2001 and going forever.
time-range xyzabsolute start 12:00 1 January 2001!ip access-list extended northeastpermit ip any any time-range xyz!interface ethernet 0ip access-group northeast inThe following example permits UDP traffic until noon on December 31, 2000. After that time, UDP traffic is no longer allowed out Ethernet interface 0.
time-range abcabsolute end 12:00 31 December 2000!ip access-list extended northeastpermit udp any any time-range abc!interface ethernet 0ip access-group northeast outThe following example permits UDP traffic out Ethernet interface 0 on weekends only, from 8:00 a.m. on January 1, 1999 to 6:00 p.m. on December 31, 2001:
time-range testabsolute start 8:00 1 January 1999 end 18:00 31 December 2001 periodic weekends 00:00 to 23:59!ip access-list extended northeastpermit udp any any time-range test!interface ethernet 0ip access-group northeast outRelated Commands
activation-character
To define the character you enter at a vacant terminal to begin a terminal session, use the activation-character command in line configuration mode. To make any character activate a terminal, use the no form of this command.
activation-character ascii-number
no activation-character
Syntax Description
Defaults
Return (decimal 13)
Command Modes
Line configuration
Command History
Usage Guidelines
See the "ASCII Character Set and Hex Values" appendix for a list of ASCII characters.
Note
Examples
The following example sets the activation character for the console to Delete, which is decimal character 127:
Router(config)# line consoleRouter(config-line)# activation-character 127alias
To create a command alias, use the alias command in global configuration mode. To delete all aliases in a command mode or to delete a specific alias, and to revert to the original command syntax, use the no form of this command.
alias mode command-alias original-command
no alias mode [command-alias]
Syntax Description
mode
Command mode of the original and alias commands.
command-alias
Command alias.
original-command
Original command syntax.
Defaults
A set of six basic EXEC mode aliases are enabled by default. See the "Usage Guidelines" section of this command for a list of default aliases.
Command Modes
Global configuration
Command History
Usage Guidelines
You can use simple words or abbreviations as command aliases.
Table 5 lists the basic EXEC mode aliases that are enabled by default.
Table 5 Default Command Aliases
h
help
lo
logout
p
ping
r
resume
s
show
w
where
The default aliases in Table 5 are predefined. These default aliases can be disabled with the no alias exec command.
Common keyword aliases (which cannot be disabled) include running-config (keyword alias for system:running-config) and startup-config (keyword alias for nvram:startup-config). See the description of the copy command for more information about these keyword aliases.
Note that aliases can be configured for keywords instead of entire commands. You can create, for example, an alias for the first part of any command and still enter the additional keywords and arguments as normal.
To determine the value for the mode argument, enter the command mode in which you would issue the original command (and in which you will issue the alias) and enter the ? command. The name of the command mode should appear at the top of the list of commands. For example, the second line in the following sample output shows the name of the command mode as "Interface configuration":
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface e0Router(config-if)# ?Interface configuration commands:access-expression Build a bridge boolean access expression...To match the name of the command mode to the acceptable mode keyword for the alias command, issue the alias ? command. As shown in the following sample output, the keyword needed to create a command alias for the access-expression command is interface:
Router(config)# alias ?accept-dialin VPDN group accept dialin configuration modeaccept-dialout VPDN group accept dialout configuration modeaddress-family Address Family configuration modecall-discriminator Call Discriminator Configurationcascustom Cas custom configuration modeclid-group CLID group configuration modeconfigure Global configuration modecongestion Frame Relay congestion configuration modecontroller Controller configuration modecptone-set custom call progress tone configuration modecustomer-profile customer profile configuration modedhcp DHCP pool configuration modednis-group DNIS group configuration modeexec Exec modeflow-cache Flow aggregation cache config modefr-fr FR/FR connection configuration modeinterface Interface configuration mode...Router(config)# alias interface express access-expressionFor a list of command modes with descriptions and references to related documentation, refer to the "Cisco IOS Command Modes" appendix of the Cisco IOS Configuration Fundamentals Configuration Guide.
When you use online help, command aliases are indicated by an asterisk (*), and displayed in the following format:
*command-alias=original-command
For example, the lo command alias is shown here along with other EXEC mode commands that start with "lo":
Router# lo?*lo=logout lock login logoutWhen you use online help, aliases that contain multiple keyword elements separated by spaces are displayed in quotes, as shown here:
Router(config)#alias exec device-mail telnet device.cisco.com 25Router(config)#endRouter#device-mail?*device-mail="telnet device.cisco.com 25"To 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(config)#alias exec td telnet deviceRouter(config)#endRouter# t?telnet terminal test tn3270 traceTo circumvent command aliases, use a space before entering the command. In the following example, the command alias express is not recognized because a space is used before the command.
Router(config-if)#exp?*express=access-expressionRouter(config-if)# express ?% Unrecognized commandAs 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 telnet device. The /debug and /line switches can be added to telnet device to modify the command:
Router(config)#alias exec td telnet deviceRouter(config)#endRouter#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 command alias. Partial syntax for aliases is not accepted. In the following example, the parser does not recognize the command t as indicating the alias td:
Router# t% Ambiguous command: "t"Examples
In the following example, the alias fixmyrt is configured for the clear iproute 192.168.116.16 EXEC mode command:
Router(config)#alias exec fixmyrt clear ip route 192.168.116.16In the following example, the alias express is configured for the first part of the access-expression interface configuration command:
Router#configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)#interface e0Router(config-if)#?Interface configuration commands:access-expression Build a bridge boolean access expression...Router(config-if)#exitRouter(config)#alias ?accept-dialin VPDN group accept dialin configuration modeaccept-dialout VPDN group accept dialout configuration modeaddress-family Address Family configuration modecall-discriminator Call Discriminator Configurationcascustom Cas custom configuration modeclid-group CLID group configuration modeconfigure Global configuration modecongestion Frame Relay congestion configuration modecontroller Controller configuration modecptone-set custom call progress tone configuration modecustomer-profile customer profile configuration modedhcp DHCP pool configuration modednis-group DNIS group configuration modeexec Exec modeflow-cache Flow aggregation cache config modefr-fr FR/FR connection configuration modeinterface Interface configuration mode...Router(config)#alias interface express access-expressionRouter(config)#int e0Router(config-if)#exp?*express=access-expressionRouter(config-if)#express ?input Filter input packetsoutput Filter output packets!Note that the true form of the command/keyword alias appears on the screen after issuing!the express ? command.Router(config-if)#access-expression ?input Filter input packetsoutput Filter output packetsRouter(config-if)#ex?*express=access-expression exit!Note that in the following line, a space is used before the ex? command!so the alias is not displayed.Router(config-if)# ex?exit!Note that in the following line, the alias cannot be recognized because!a space is used before the command.Router#(config-if)# express ?% Unrecognized commandRouter(config-if)# endRouter# show alias interfaceInterface configuration mode aliases:express access-expressionRelated Commands
alias (boomerang)
To configure an alias name for a specified domain, use the alias command in boomerang configuration mode. To remove this command from the configuration file and restore the system to its default condition with respect to this command, use the no form of this command.
alias alias-name
no alias alias-name
Syntax Description
Defaults
No domain name alias is configured.
Command Modes
Boomerang configuration
Command History
Usage Guidelines
The alias command can be used only on a Director Response Protocol (DRP) agent. The boomerang client is the DRP agent.
Use the alias command to specify one or more alias names for an existing domain. Because the boomerang client maintains separate counters for requests received for each domain name (alias or otherwise), use the show ip drp boomerang command to view these counters for a specified domain name and each of its aliases.
Examples
In the following example, the domain name alias is configured for www.boom1.com. The new alias for www.boom1.com is www.boom2.com:
Router(config)# ip drp domain www.boom1.comRouter(config-boomerang)# alias www.boom2.comRouter# show running-config...ip drp domain www.boom1.comalias www.boom2.comRelated Commands
announce config
To specify that an unsolicited configuration inventory is sent out by the CNS inventory agent at bootup, use the announce config command in CNS inventory configuration mode. To disable the sending of the configuration inventory, use the no form of this command.
announce config
no announce config
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
CNS inventory configuration
Command History
Usage Guidelines
Use this command to limit inventory requests by the CNS inventory agent. When configured, the routing device details will be announced on the CNS Event Bus, but the routing device will not respond to any queries from the CNS Event Bus.
Examples
The following example shows how to configure the CNS inventory agent to send out an unsolicited configuration inventory one time only at bootup:
Router(config)# cns inventoryRouter(cns_inv)# announce configRelated Commands
cns inventory
Enables the CNS inventory agent and enters CNS inventory configuration mode.
async-bootp
To configure extended BOOTP requests for asynchronous interfaces as defined in RFC 1084, use the async-bootp command in global configuration mode. To restore the default, use the no form of this command.
async-bootp tag [:hostname] data
no async-bootp
Syntax Description
tag
Item being requested; expressed as filename, integer, or IP dotted decimal address. See Table 6 for possible keywords.
:hostname
(Optional) This entry applies only to the specified host. The :hostname argument accepts both an IP address and a logical host name.
data
List of IP addresses entered in dotted decimal notation or as logical host names, a number, or a quoted string.
Defaults
If no extended BOOTP commands are entered, the Cisco IOS software generates a gateway and subnet mask appropriate for the local network.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the show async-bootp EXEC command to list the configured parameters. Use the no async-bootp command to clear the list.
Examples
The following example illustrates how to specify different boot files: one for a PC, and one for a Macintosh. With this configuration, a BOOTP request from the host on 172.30.1.1 results in a reply listing the boot filename as pcboot. A BOOTP request from the host named "mac" results in a reply listing the boot filename as "macboot."
async-bootp bootfile :172.30.1.1 "pcboot"async-bootp bootfile :mac "macboot"The following example specifies a subnet mask of 255.255.0.0:
async-bootp subnet-mask 255.255.0.0The following example specifies a negative time offset of the local subnetwork of 3600 seconds:
async-bootp time-offset -3600The following example specifies the IP address of a time server:
async-bootp time-server 172.16.1.1Related Commands
show async bootp
Displays the extended BOOTP request parameters that have been configured for asynchronous interfaces.
atm-slm statistics
To enable the Service Assurance Agent (SAA) ATM Service Level Monitoring (SLM) feature, use the atm-slm statistics command in global configuration mode. To disable ATM SLM, use the no form of this command.
atm-slm statistics
no atm-slm statistics
Syntax Description
This command has no arguments or keywords.
Defaults
ATM Service Level Monitoring is disabled.
Command Modes
Global configuration mode
Command History
Usage Guidelines
To generate and retrieve performance statistics for ATM services using SAA, the ATM SLM feature must first be enabled on the device using the atm-slm statistics global configuration command. (Note that these performance statistics can be retrieved by other applications such as CNS or Visual Uptime.) If this command is not used, SAA SLM operations (type slm atm pvc, type slm atm interface, or type slm controller) cannot be configured on the system.
Disabling the ATM SLM feature with the no atm-slm statistics command will cause any currently configured SAA SLM operations to be removed from the configuration. When ATM SLM is disabled, no CNS/XML requests are processed.
Examples
In the following example, the ATM SLM feature is enabled before an SAA SLM operation is configured for ATM interface 0/1:
Router(config)# atm-slm statisticsRouter(config)# rtr 1Router(config-rtr)# type slm atm interface ATM0/1Router(config-rtr-slm)# enhanced-history interval 900 buckets 100Router(config-rtr-slm)# exitRouter(config)# rtr schedule 1 start-time now life foreverRelated Commands
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 command in privileged EXEC mode. To exit from the Cisco IOS software image on the line card and return to the Cisco IOS image on the giabit route processor (GRP), use the exit command.
attach slot-number
Syntax Description
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
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 EXEC 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
Examples
In the following example, the user 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
autobaud
To set the line for automatic baud rate detection (autobaud), use the autobaud command in line configuration mode. To disable automatic baud detection, use the no form of this command.
autobaud
no autobaud
Syntax Description
This command has no arguments or keywords.
Defaults
Autobaud detection is disabled. Fixed speed of 9600 bps.
Command Modes
Line configuration
Command History
Usage Guidelines
The autobaud detection supports a range from 300 to 19200 baud. A line set for autobaud cannot be used for outgoing connections, nor can you set autobaud capability on a line using 19200 baud when the parity bit is set (because of hardware limitations).
Note
Examples
In the following example, the auxiliary port is configured for autobaud detection:
Router(config)# line auxRouter(config-line)# autobaudbanner exec
To specify and enable a message to be displayed when an EXEC process is created (an EXEC banner), use the banner exec command in global configuration mode. To delete the existing EXEC banner, use the no form of this command.
banner exec d message d
no banner exec
Syntax Description
d
Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.
message
Message text. You can include tokens in the form $(token) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in Table 7.
Defaults
Disabled (no EXEC banner is displayed).
Command Modes
Global configuration
Command History
10.0
This command was introduced.
11.3(7.5)AA
Token functionality was introduced.
12.0(3)T
Token functionality was integrated into Cisco IOS Release 12.0(3)T.
Usage Guidelines
This command specifies a message to be displayed when an EXEC process is created (a line is activated, or an incoming connection is made to a vty). Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
When a user connects to a router, the message-of-the-day (MOTD) banner appears first, followed by the login banner and prompts. After the user logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.
To disable the EXEC banner on a particular line or lines, use the no exec-banner line configuration command.
To customize the banner, use tokens in the form $(token) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router's host name and IP address. The tokens are described in Table 7.
Examples
The following example sets an EXEC banner that uses tokens. The percent sign (%) is used as a delimiting character. Notice that the $(token) syntax is replaced by the corresponding configuration variable.
Router(config)# banner exec %Enter TEXT message. End with the character '%'.Session activated on line $(line), $(line-desc). Enter commands at the prompt.%When a user logs on to the system, the following output is displayed:
User Access VerificationUsername: joeuserPassword: <password>Session activated on line 50, vty default line. Enter commands at the prompt.Router>Related Commands
banner incoming
To define and enable a banner to be displayed when there is an incoming connection to a terminal line from a host on the network, use the banner incoming command in global configuration mode. To delete the incoming connection banner, use the no form of this command.
banner incoming d message d
no banner incoming
Syntax Description
d
Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.
message
Message text. You can include tokens in the form $(token) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in Table 8.
Defaults
Disabled (no incoming banner is displayed).
Command Modes
Global configuration
Command History
10.0
This command was introduced.
11.3(7.5)AA
Token functionality was introduced.
12.0(3)T
Token functionality was integrated into Cisco IOS Release 12.0(3)T.
Usage Guidelines
Follow the banner incoming command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
An incoming connection is one initiated from the network side of the router. Incoming connections are also called reverse Telnet sessions. These sessions can display MOTD banners and incoming banners, but they do not display EXEC banners. Use the no motd-banner line configuration command to disable the MOTD banner for reverse Telnet sessions on asynchronous lines.
When a user connects to the router, the message-of-the-day (MOTD) banner (if configured) appears first, before the login prompt. After the user successfully logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.
Incoming banners cannot be suppressed. If you do not want the incoming banner to appear, you must delete it with the no banner incoming command.
To customize the banner, use tokens in the form $(token) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router's host name and IP address. The tokens are described in Table 8.
Examples
The following example sets an incoming connection banner. The pound sign (#) is used as a delimiting character.
Router(config)# banner incoming #This is the Reuses router.#The following example sets an incoming connection banner that uses several tokens. The percent sign (%) is used as a delimiting character.
darkstar(config)# banner incoming %Enter TEXT message. End with the character '%'.You have entered $(hostname).$(domain) on line $(line) ($(line-desc)) %When the incoming connection banner is executed, the user will see the following banner. Notice that the $(token) syntax is replaced by the corresponding configuration variable.
You have entered darkstar.ourdomain.com on line 5 (Dialin Modem)Related Commands
banner login
To define and enable a customized banner to be displayed before the username and password login prompts, use the banner login command in global configuration mode. To disable the login banner, use no form of this command.
banner login d message d
no banner login
Syntax Description
d
Delimiting character of your choice—a pound sign (#), for example. You cannot use the delimiting character in the banner message.
message
Message text. You can include tokens in the form $(token) in the message text. Tokens will be replaced with the corresponding configuration variable. Tokens are described in Table 9.
Defaults
Disabled (no login banner is displayed).
Command Modes
Global configuration
Command History
10.0
This command was introduced.
11.3(7.5)AA
Token functionality was introduced.
12.0(3)T
Token functionality was integrated into Cisco IOS Release 12.0(3)T.
Usage Guidelines
Follow the banner login command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
When a user connects to the router, the message-of-the-day (MOTD) banner (if configured) appears first, followed by the login banner and prompts. After the user successfully logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.
To customize the banner, use tokens in the form $(token) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router's host name and IP address. The tokens are described in Table 9.
Examples
The following example sets a login banner. Double quotes (") are used as the delimiting character.
Router# banner login " Access for authorized users only. Please enter your username and password. "The following example sets a login banner that uses several tokens. The percent sign (%) is used as the delimiting character.
darkstar(config)# banner login %Enter TEXT message. End with the character '%'.You have entered $(hostname).$(domain) on line $(line) ($(line-desc)) %When the login banner is executed, the user will see the following banner. Notice that the $(token) syntax is replaced by the corresponding configuration variable.
You have entered darkstar.ourdomain.com on line 5 (Dialin Modem)Related Commands
banner motd
To define and enable a message-of-the-day (MOTD) banner, use the banner motd command in global configuration mode. To delete the MOTD banner, use the no form of this command.
banner motd d message d
no banner motd
Syntax Description
Defaults
Disabled (no MOTD banner is displayed).
Command Modes
Global configuration
Command History
10.0
This command was introduced.
11.3(7.5)AA
Token functionality was introduced.
12.0(3)T
Token functionality was integrated into Cisco IOS Release 12.0(3)T.
Usage Guidelines
Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
This MOTD banner is displayed to all terminals connected and is useful for sending messages that affect all users (such as impending system shutdowns). Use the no exec-banner or no motd-banner command to disable the MOTD banner on a line. The no exec-banner command also disables the EXEC banner on the line.
When a user connects to the router, the MOTD banner appears before the login prompt. After the user logs in to the router, the EXEC banner or incoming banner will be displayed, depending on the type of connection. For a reverse Telnet login, the incoming banner will be displayed. For all other connections, the router will display the EXEC banner.
To customize the banner, use tokens in the form $(token) in the message text. Tokens will display current Cisco IOS configuration variables, such as the router's host name and IP address. The tokens are described in Table 10.
Examples
The following example configures an MOTD banner. The pound sign (#) is used as a delimiting character.
Router# banner motd # Building power will be off from 7:00 AM until 9:00 AM this coming Tuesday. #The following example configures an MOTD banner with a token. The percent sign (%) is used as a delimiting character.
darkstar(config)# banner motd %Enter TEXT message. End with the character '%'.Notice: all routers in $(domain) will be upgraded beginning April 20%When the MOTD banner is executed, the user will see the following. Notice that the $(token) syntax is replaced by the corresponding configuration variable.
Notice: all routers in ourdomain.com will be upgraded beginning April 20Related Commands
banner slip-ppp
To customize the banner that is displayed when a Serial Line Internet Protocol (SLIP) or PPP connection is made, use the banner slip-ppp command in global configuration mode. To restore the default SLIP or PPP banner, use the no form of this command.
banner slip-ppp d message d
no banner slip-ppp
Syntax Description
Defaults
The default SLIP or PPP banner message is:
Entering encapsulation mode. Async interface address is unnumbered (Ethernet0) Your IP address is 10.000.0.0 MTU is 1500 bytesThe banner message when using the service old-slip-prompt command is:
Entering encapsulation mode.Your IP address is 10.100.0.0 MTU is 1500 byteswhere encapsulation is SLIP or PPP.
Command Modes
Global configuration
Command History
Usage Guidelines
Follow this command with one or more blank spaces and a delimiting character of your choice. Then enter one or more lines of text, terminating the message with the second occurrence of the delimiting character.
Use this command to define a custom SLIP or PPP connection message. This is useful when legacy client applications require a specialized connection string. To customize the banner, use tokens in the form $(token) in the message text. Tokens will display current Cisco IOS configuration variables, such as the routers host name, IP address, encapsulation type, and Maximum Transfer Unit (MTU) size. The banner tokens are described in Table 11.
Examples
The following example sets the SLIP/PPP banner using several tokens and the percent sign (%) as the delimiting character:
Router(config)# banner slip-ppp %Enter TEXT message. End with the character '%'.Starting $(encap) connection from $(gate-ip) to $(peer-ip) using a maximum packet size of $(mtu) bytes... %The new SLIP/PPP banner will now be displayed when the slip EXEC command is used. Notice that the $(token) syntax is replaced by the corresponding configuration variable.
Router# slipStarting SLIP connection from 172.16.69.96 to 192.168.1.200 using a maximum packet size of 1500 bytes...Related Commands
boot
To boot the router manually, use the boot command in ROM monitor mode. The syntax of this command varies according to the platform and ROM monitor version.
boot
boot file-url
boot filename [tftp-ip-address]
boot flash [flash-fs:][partition-number:][filename]
Cisco 7000 Series, 7200 Series, 7500 Series Routers
boot flash-fs:[filename]
Cisco 1600 and Cisco 3600 Series Routers
boot [flash-fs:][partition-number:][filename]
Syntax Description
Defaults
For most platforms, if you enter the boot command and press Enter, the router boots from ROM by default. However, for some platforms, such as the Cisco 3600 series routers, if you enter the boot command and press Return, the router boots the first image in Flash memory. Refer to the documentation for your platform for information about the default image.
If the partition-number is not specified, the first partition is used.
If the filename is not specified, the first file in the partition or file system is used.
For other defaults, see the "Syntax Description" section.
Command Modes
ROM monitor
Command History
Usage Guidelines
To determine which form of this command to use, refer to the documentation for your platform or use the CLI help (?) feature.
Use this command only when your router cannot find the boot configuration information needed in NVRAM. To enter ROM monitor mode, use one of the following methods:
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The ROM Monitor prompt is either ">" or, for newer platforms, "rommon x>". Enter only lowercase commands.
These commands work only if there is a valid image to boot. Also, from the ROM monitor prompt, issuing a prior reset command is necessary for the boot to be consistently successful.
Refer to your hardware documentation for information on correct jumper settings for your platform.
Note
Examples
In the following example, a router is manually booted from ROM:
> bootF3:(ROM Monitor copyrights)In the following example, a router boots the file named routertest from a network server with the IP address 172.16.15.112 using the file-url syntax:
> boot tftp://172.16.15.112/routertestF3(ROM Monitor copyrights)The following example shows the boot flash command without the filename argument. The first valid file in Flash memory is loaded.
> boot flashF3: 1858656+45204+166896 at 0x1000Booting gs7-k from flash memory RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR [OK - 1903912/13765276 bytes]F3: 1858676+45204+166896 at 0x1000(ROM Monitor copyrights)The following example boots from Flash memory using the file named gs7-k:
> boot flash gs7-kF3: 1858656+45204+166896 at 0x1000Booting gs7-k from flash memory RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR [OK - 1903912/13765276 bytes]F3: 1858676+45204+166896 at 0x1000(ROM Monitor copyrights)In the following example, the boot flash flash: command boots the relocatable image file named igs-bpx-l from partition 2 in Flash memory:
> boot flash flash:2:igs-bpx-lF3: 3562264+98228+303632 at 0x30000B4(ROM Monitor copyrights)In the following command, the Cisco 7000 family router accepts the flash keyword for compatibility but ignores it, and boots from slot 0:
> boot flash slot0:gs7-k-mz.103-9F3: 8468+3980384+165008 at 0x1000In the following example, the command did not function because it must be entered in lowercase:
rommon 10 > BOOTcommand "BOOT" not foundThe following example boots the first file in the first partition of internal Flash memory of a Cisco 3600 series router:
> boot flash:The following example boots the first image file in the first partition of the Flash memory card in slot 0 of a Cisco 3600 series router:
> boot slot0:The following example shows the ROM monitor booting the first file in the first Flash memory partition on a Cisco 1600 series router:
> boot flash:Related Commands
continue
Returns to EXEC mode from ROM monitor mode by completing the boot process.
boot bootldr
To specify the location of the boot image that ROM uses for booting, use the boot bootldr command in global configuration mode. To remove this boot image specification, use the no form of this command.
boot bootldr file-url
no boot bootldr
Syntax Description
Defaults
Refer to your platform documentation for the location of the default boot image.
Command Modes
Global configuration
Command History
Usage Guidelines
The boot bootldr command sets the BOOTLDR variable in the current running configuration. You must specify both the Flash file system and the filename.
Note
The no form of the command sets the BOOTLDR variable to a null string. On the Cisco 7000 family routers, a null string causes the first image file in boot Flash memory to be used as the boot image that ROM uses for booting.
Use the show boot command to display the current value for the BOOTLDR variable.
Examples
In the following example, the internal Flash memory contains the boot image:
boot bootldr bootflash:boot-imageThe following example specifies that the Flash memory card inserted in slot 0 contains the boot image:
boot bootldr slot0:boot-imageRelated Commands
boot bootstrap
To configure the filename that is used to boot a secondary bootstrap image, use the boot bootstrap command in global configuration mode. To disable booting from a secondary bootstrap image, use the no form of this command.
boot bootstrap file-url
no boot bootstrap file-url
boot bootstrap flash [filename]
no boot bootstrap flash [filename]
boot bootstrap [tftp] filename [ip-address]
no boot bootstrap [tftp] filename [ip-address]
Syntax Description
Defaults
No secondary bootstrap
Command Modes
Global configuration
Command History
Usage Guidelines
The boot bootstrap command causes the router to load a secondary bootstrap image from the specied URL, such as from a remote server. After the bootstrap image is loaded, the bootstrap image loads the specified system image file. See the appropriate hardware installation guide for details on the setting the configuration register and secondary bootstrap filename.
Use this command when you have attempted to load a system image but have run out of memory even after compressing the system image. Secondary bootstrap images allows you to load a larger system image through a smaller secondary image.
Examples
In the following example, the system image file named sysimage-2 will be loaded by using a secondary bootstrap image:
Router(config)# boot bootstrap bootflash:sysimage-2boot buffersize
The boot buffersize global configuration command no longer functions.
Executing this command has no effect on the system. Using this command will not generate CLI errors; the boot buffersize command syntax is still allowed to be entered at the CLI and in configuration files in order to accommodate existing configuration scripts used by customers.
Command History
boot config
To specify the device and filename of the configuration file from which the router configures itself during initialization (startup), use the boot config command in global configuration mode. This command is only available on Class A file system platforms. To remove the specification, use the no form of this command.
boot config file-system-prefix:[directory/]filename
no boot config
Syntax Description
Defaults
NVRAM (nvram:)
Command Modes
Global configuration
Command History
Usage Guidelines
This command is only available on Class A file system platforms.
You set the CONFIG_FILE environment variable in the current running memory when you use the boot config command. This variable specifies the configuration file used for initialization (startup). The configuration file must be an ASCII file located in either NVRAM or Flash memory.
Note
The software displays an error message and does not update the CONFIG_FILE environment variable in the following situations:
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The router uses the NVRAM configuration during initialization when the CONFIG_FILE environment variable does not exist or when it is null (such as at first-time startup). If the software detects a problem with NVRAM or the configuration it contains, the device enters setup mode. See the "Setup Command" chapter in this publication for more information on the setup command facility.
When you use the no form of this command, the router returns to using the default NVRAM configuration file as the startup configuration.
Examples
In the following example, the first line specifies that the router should use the configuration file named router-config located in internal Flash memory to configure itself during initialization. The third line copies the specification to the startup configuration, ensuring that this specification will take effect upon the next reload.
Router(config)# boot config flash:router-configRouter(config)# endRouter# copy system:running-config nvram:startup-configThe following example instructs a Cisco 7500 series router to use the configuration file named router-config located on the Flash memory card inserted in the second PCMCIA slot of the RSP card during initialization. The third line copies the specification to the startup configuration, ensuring that this specification will take effect upon the next reload.
Router (config)# boot config slot1:router-configRouter (config)# endRouter# copy system:running-config nvram:startup-configRelated Commands
boot host
To specify the host-specific configuration file to be used at the next system startup, use the boot host command in global configuration mode. To restore the host configuration filename to the default, use the no form of this command.
boot host remote-url
no boot host remote-url
Syntax Description
Defaults
If you do not specify a filename using this command, the router uses its configured host name to request a configuration file from a remote server. To form the configuration filename, the router converts its name to all lowercase letters, removes all domain information, and appends -confg or -config.
Command Modes
Global configuration
Command History
Usage Guidelines
This command instructs the system to "Boot using host-specific configuration file x," where x is the filename specified in the remote-url argument. In other words, this command specifies the remote location and filename of the host-specific configuration file to be used at the next system startup, as well as the protocol to be used to obtain the file.
Before using the boot host command, use the service config global configuration command to enable the loading of the specified configuration file at reboot time. Without this command, the router ignores the boot host command and uses the configuration information in NVRAM. If the configuration information in NVRAM is invalid or missing, the service config command is enabled automatically.
The network server will attempt to load two configuration files from remote hosts. The first is the network configuration file containing commands that apply to all network servers on a network. Use the boot network command to identify the network configuration file. The second is the host configuration file containing commands that apply to one network server in particular. Use the boot host command to identify the host configuration file.
Note
With Cisco IOS Release 12.3(2)T , 12.3(1)B, and later, you no longer have to specify the service config command for the boot host or boot network command to be active.
If you specify both the no service config command and the boot host command, the router attempts to find the specified host configuration file.
The service config command can also be used without the boot host or boot network command. If you do not specify host or network configuration filenames, the router uses the default configuration files. The default network configuration file is network-confg. The default host configuration file is host-confg, where host is the hostname of the router. If the Cisco IOS software cannot resolve its hostname, the default host configuration file is router-confg.Loading a Configuration File Using rcp
The rcp software requires that a client send the remote username on each rcp request to the network server. If the server has a directory structure (such as UNIX systems), the rcp implementation searches for the configuration files starting in the directory associated with the remote username.
When you load a configuration file from a server using rcp, the Cisco IOS software sends the first valid username in the following list:
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3.
Note
Loading a Configuration File Using FTP
The FTP protocol requires a client to send a remote username and password on each FTP request to a server. The username and password must be associated with an account on the FTP server. If the server has a directory structure, the configuration file or image copied from the directory is associated with the username on the server. Refer to the documentation for your FTP server for more details.
When you load a configuration file from a server using FTP, the Cisco IOS software sends the first valid username in the following list:
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The router sends the first valid password in the following list:
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Examples
The following example sets the host filename to wilma-confg at address 192.168.7.19:
Router(config)# boot host tftp://192.168.7.19/usr/local/tftpdir/wilma-confgRouter(config)# service configRelated Commands
boot network
To change the default name of the network configuration file from which to load configuration commands, use the boot network command in global configuration mode. To restore the network configuration filename to the default, use the no form of this command.
boot network remote-url
no boot network remote-url
Syntax Description
Defaults
The default filename is network-config.
Command Modes
Global configuration
Command History
Usage Guidelines
This command instructs the system to "Boot using network configuration file x," where x is the filename specified in the remote-url argument. This command specifies the remote location and filename of the network configuration file to be used at the next system startup, as well as the protocol to be used to obtain the file.
When booting from a network server, routers ignore routing information, static IP routes, and bridging information. As a result, intermediate routers are responsible for handling FTP, rcp, or TFTP requests. Before booting from a network server, verify that a server is available by using the ping command.
Use theservice config command to enable the loading of the specified configuration file at reboot time. Without this command, the router ignores the boot network command and uses the configuration information in NVRAM. If the configuration information in NVRAM is invalid or missing, the service config command is enabled automatically.
The network server will attempt to load two configuration files from remote hosts. The first is the network configuration file containing commands that apply to all network servers on a network. Use the boot network command to identify the network configuration file. The second is the host configuration file containing commands that apply to one network server in particular. Use the boot host command to identify the host configuration file.
Note
With Cisco IOS Release 12.3(2)T , 12.3(1)B, and later, you no longer have to specify the service config command for the boot host or boot network command to be active.
If you specify both the no service config command and the boot host command, the router attempts to find the specified host configuration file.
Theservice config command can also be used without the boot host or boot network command. If you do not specify host or network configuration filenames, the router uses the default configuration files. The default network configuration file is network-confg. The default host configuration file is host-confg, where host is the hostname of the router. If the Cisco IOS software cannot resolve its hostname, the default host configuration file is router-confg.Loading a Configuration File Using rcp
The rcp software requires that a client send the remote username on each rcp request to the network server. If the server has a directory structure (such as UNIX systems), the rcp implementation searches for the configuration files starting in the directory associated with the remote username.
When you load a configuration file from a server using rcp, the Cisco IOS software sends the first valid username in the following list:
1.
2.
3.
Note
Loading a Configuration File Using FTP
The FTP protocol requires a client to send a remote username and password on each FTP request to a server. The username and password must be associated with an account on the FTP server. If the server has a directory structure, the configuration file or image copied from the directory associated with the username on the server. Refer to the documentation for your FTP server for more details.
When you load a configuration file from a server using FTP, the Cisco IOS software sends the first valid username in the following list:
1.
2.
3.
The router sends the first valid password in the following list:
1.
2.
3.
Examples
The following example changes the network configuration filename to bridge_9.1 and uses the default broadcast address:
Router(config)# boot network tftp:bridge_9.1Router(config)# service configThe following example changes the network configuration filename to bridge_9.1, specifies that rcp is to be used as the transport mechanism, and gives 172.16.1.111 as the IP address of the server on which the network configuration file resides:
Router(config)# service configRouter(config)# boot network rcp://172.16.1.111/bridge_9.1Related Commands
boot system
To specify the system image that the router loads at startup, use one of the following boot system commands in global configuration mode. To remove the startup system image specification, use the no form of this command.
boot system {file-url | filename}
no boot system {file-url | filename}
boot system flash [flash-fs:] [partition-number:] [filename]
no boot system flash [flash-fs:] [partition-number:] [filename]
boot system mop filename [mac-address] [interface]
no boot system mop filename [mac-address] [interface]
boot system rom
no boot system rom
boot system {rcp | tftp | ftp} filename [ip-address]
no boot system {rcp | tftp | ftp} filename [ip-address]
Syntax Description
Defaults
If you configure the router to boot from a network server but do not specify a system image file with the boot system command, the router uses the configuration register settings to determine the default system image filename. The router forms the default boot filename by starting with the word cisco and then appending the octal equivalent of the boot field number in the configuration register, followed by a hyphen (-) and the processor type name (cisconn-cpu). Refer to the appropriate hardware installation guide for details on the configuration register and default filename. See also the config-register or confreg command.
Command Modes
Global configuration
Command History
Usage Guidelines
For this command to work, the config-register command must be set properly.
Enter several boot system commands to provide a fail-safe method for booting your router. The router stores and executes the boot system commands in the order in which you enter them in the configuration file. If you enter multiple boot commands of the same type—for example, if you enter two commands that instruct the router to boot from different network servers—then the router tries them in the order in which they appear in the configuration file. If a boot system command entry in the list specifies an invalid device, the router omits that entry. Use the boot system rom command to specify use of the ROM system image as a backup to other boot commands in the configuration.
For some platforms, the boot image must be loaded before the system image is loaded. However, on many platforms, the boot image is loaded only if the router is booting from a network server or if the flash file system is not specified. If the file system is specified, the router will boot faster because it need not load the boot image first.
This section contains the following usage guideline topics:
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Changing the List of Boot System Commands
To remove a single entry from the bootable image list, use the no form of the command with an argument. For example, to remove the entry that specifies a bootable image on a flash memory card inserted in the second slot, use the no boot system flash slot1:[filename] command. All other entries in the list remain.
To eliminate all entries in the bootable image list, use the no boot system command. At this point, you can redefine the list of bootable images using the previous boot system commands. Remember to save your changes to your startup configuration by issuing the copy system:running-config nvram:startup-config command.
Each time you write a new software image to flash memory, you must delete the existing filename in the configuration file with the no boot system flash filename command. Then add a new line in the configuration file with the boot system flash filename command.
Note
Booting Compressed Images
You can boot the router from a compressed image on a network server. When a network server boots software, both the image being booted and the running image must fit into memory. Use compressed images to ensure that enough memory is available to boot the router. You can compress a software image on any UNIX platform using the compress command. Refer to your UNIX platform's documentation for the exact usage of the compress command. (You can also uncompress data with the UNIX uncompress command.)
Understanding rcp
The rcp requires that a client send the remote username in an rcp request to a server. When the router executes the boot system rcp command, the Cisco IOS software sends the hostname as both the remote and local usernames by default. For the rcp to execute properly, an account must be defined on the network server for the remote username configured on the router.
If the server has a directory structure, the rcp software searches for the system image to boot from the remote server relative to the directory of the remote username.
By default, the router software sends hostname as the remote username. You can override the default remote username by using the ip rcmd remote-username command. For example, if the system image resides in the home directory of a user on the server, you can specify that user's name as the remote username.
Understanding TFTP
You need a TFTP server running in order to retrieve the router image from the host.
Understanding FTP
You need to an FTP server running in order to fetch the router image from the host. You also need an account on the server or anonymous file access to the server.
Stopping Booting and Entering ROM Monitor Mode
During the first 60 seconds of startup, you can force the router to stop booting by pressing the Break key. The router will enter ROM Monitor mode, where you can change the configuration register value or boot the router manually.
Cisco 1600 Series, Cisco 3600 Series, and Cisco 7000 Family Router Notes
For the Cisco 3600 series and Cisco 7000 family, the boot system command modifies the BOOT variable in the running configuration. The BOOT variable specifies a list of bootable images on various devices.
Note
To view the contents of the BOOT variable, use the show bootenv privileged EXEC command.
Examples
The following example illustrates a configuration that specifies two possible internetwork locations for a system image, with the ROM software being used as a backup:
Router(config)# boot system tftp://192.168.7.24/cs3-rx.90-1Router(config)# boot system tftp://192.168.7.19/cs3-rx.83-2Router(config)# boot system romThe following example boots the system boot relocatable image file named igs-bpx-l from partition 2 of the flash device:
Router(config)# boot system flash:2:igs-bpx-lThe following example instructs the router to boot from an image located on the flash memory card inserted in slot 0:
Router(config)# boot system slot0:new-configThe following example specifies the file named new-ios-image as the system image for a Cisco 3600 series router to load at startup. This file is located in the fourth partition of the flash memory card in slot 0.
Router(config)# boot system slot0:4:dirt/images/new-ios-imageThis example boots from the image file named c1600-y-l in partition 2 of flash memory of a Cisco 1600 series router:
Router(config)# boot system flash:2:c1600-y-lRelated Commands
boot-end-marker
The boot-start-marker and boot-end-marker flags, which can be seen in Cisco IOS software configuration files, are not CLI commands. These markers are written to configuration files automatically to flag the beginning and end of the boot commands (boot statements). By flagging boot statements, these markers allow the router to more reliably load Cisco IOS images during bootup.
A boot statement is one or more lines in a configuration file that tells the router which software image to load after a powercycling (reboot). The boot-start-marker and boot-end-marker flags will appear around any boot commands, including:
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Note, however, that these markers will always appear in the output of the show running-config or more system:running-config commands, regardless of whether any actual boot commands have been entered. This means that no boot commands will appear between the markers if no boot commands have been entered, or if all boot commands have been removed from the configuration, as shown in the "Examples" section.
The boot-start-marker and boot-end-marker flags cannot be removed or modified using the CLI. These markers are written to the startup configuration file whenever a copy running-config startup-config command is issued.
These flags were also introduced to circumvent errors in the configuration file, such as a leading space before a boot command (such as those sometimes introduced by manually edited configuration files), or the use of text strings that include the word "boot" in banners or other user-specified text.
If the "boot start-marker" flag is not found in the configuration file, the system will use the traditional method to identify the boot commands. However, if you are manually creating configuration files, or copying from older Cisco IOS software releases, the addition of these markers is recommended.
Command History
12.3(3), 12.3(4)T, 12.0(26)S, 12.0(27)SV, 12.3(3)B,
The boot-start-marker and boot-end-marker flags were introduced.
Examples
In the following example, a boot command is entered, and the boot-start-marker and boot-end-marker flags are shown in the context of the startup configuration file:
Router# configure terminalEnter configuration commands, one per line. End with the end command.Router(config)# boot system slot0:Router(config)# endRouter# copy running-config startup-configRouter# show startup-configUsing 1398 out of 129016 bytes!version 12.3service timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname C3660-2!boot-start-markerboot system slot0:boot-end-marker!logging count...In the following example, the boot-start-marker and boot-end-marker flags appear in the configuration file even though no boot commands have been entered:
Router# show running-configurationCurrent configuration :3055 bytes!! No configuration change since last restart!version 12.3service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname Router!boot-start-markerboot-end-marker!...Related Commands
boot-start-marker
The boot-start-marker and boot-end-marker flags, which can be seen in Cisco IOS software configuration files, are not CLI commands. These markers are written to configuration files automatically to flag the beginning and end of the boot commands (boot statements). By flagging boot statements, these markers allow the router to more reliably load Cisco IOS images during bootup.
A boot statement is one or more lines in a configuration file that tells the router which software image to load after a powercycling (reboot). The boot-start-marker and boot-end-marker flags will appear around any boot commands, including:
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Note, however, that these markers will always appear in the output of the show running-config or more system:running-config commands, regardless of whether any actual boot commands have been entered. This means that no boot commands will appear between the markers if no boot commands have been entered, or if all boot commands have been removed from the configuration, as shown in the "Examples" section.
The boot-start-marker and boot-end-marker flags cannot be removed or modified using the CLI. These markers are written to the startup configuration file whenever a copy running-config startup-config command is issued.
These flags were also introduced to circumvent errors in the configuration file, such as a leading space before a boot command (such as those sometimes introduced by manually edited configuration files), or the use of text strings that include the word "boot" in banners or other user-specified text.
If the "boot start-marker" flag is not found in the configuration file, the system will use the traditional method to identify the boot commands. However, if you are manually creating configuration files, or copying from older Cisco IOS software releases, the addition of these markers is recommended.
Command History
12.3(3), 12.3(4)T, 12.0(26)S, 12.0(27)SV, 12.3(3)B
The boot-start-marker and boot-end-marker flags were introduced.
Examples
In the following example, a boot command is entered, and the boot-start-marker and boot-end-marker flags are shown in the context of the startup configuration file:
Router# configure terminalEnter configuration commands, one per line. End with the end command.Router(config)# boot system slot0:Router(config)# endRouter# copy running-config startup-configRouter# show startup-configUsing 1398 out of 129016 bytes!version 12.3service timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname C3660-2!boot-start-markerboot system slot0:boot-end-marker!logging count...In the following example, the boot-start-marker and boot-end-marker flags appear in the configuration file even though no boot commands have been entered:
Router# show running-configurationCurrent configuration :3055 bytes!! No configuration change since last restart!version 12.3service timestamps debug datetime msecservice timestamps log datetime msecno service password-encryption!hostname Router!boot-start-markerboot-end-marker!...Related Commands
buckets-of-history-kept
To set the number of history buckets that are kept during a Service Assurance Agent (SAA) operation's lifetime, use the buckets-of-history-kept command in SAA RTR configuration mode. To return to the default value, use the no form of this command.
buckets-of-history-kept size
no buckets-of-history-kept
Syntax Description
size
Number of history buckets kept during the lifetime of the operation. The default is 50 buckets.
Defaults
50 buckets
Command Modes
SAA RTR configuration
Command History
Usage Guidelines
History collection and statistics capturing is enabled for the following SAA operations: ICMP Echo, SNA Echo, ICMP PathEcho, UDP Echo, TcpConnect, DNS, and DLSW. History collection is not supported for HTTP and Jitter (UDP+) operations.
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 SAA RTR configuration command to collect history. You can optionally adjust the buckets-of-history-kept, filter-for-history, and samples-of-history-kept SAA RTR 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 operation. When the operation type is pathEcho, an entry is created for each hop along the path that the operation takes to reach its destination. The type of entry stored in the history table is controlled by the filter-for-history SAA RTR 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 SAA RTR configuration commands.
Each time the SAA starts an operation, a new bucket is created until the number of history buckets matches the specified size or the operation's lifetime expires. History buckets do not wrap. The operation's lifetime is defined by the rtr schedule global configuration command. The operation starts an SAA operation based on the seconds specified by the frequency SAA RTR configuration command.
Examples
The following example configures operation 1 to keep 25 history buckets during the operation lifetime:
Router(config)# rtr 1Router(config-rtr)# type echo protocol ipIcmpEcho 172.16.161.21Router(config-rtr)# buckets-of-history-kept 25Router(config-rtr)# lives-of-history-kept 1Related Commands
buffer-length
To specify the maximum length of the data stream to be forwarded, use the buffer-length command in line configuration mode. To restore the default setting, use the no form of this command.
buffer-length length
no buffer-length
Syntax Description
length
Specifies the length of the buffer in bytes. Valid values for the length argument range from 16 to 1536. The default buffer length is 1536 bytes.
Defaults
1536 bytes
Command Modes
Line configuration
Command History
Usage Guidelines
The buffer-length command configures the size of the forwarded data stream. The higher the value used for the length argument is, the longer the delay between data transmissions will be. Configuring a smaller buffer length can prevent connections from timing out inappropriately.
Examples
The following example configures a buffer length of 500 bytes:
Router(config)# line 1Router(config-line)# buffer-length 500buffers
To make adjustments to initial buffer pool settings and to the limits at which temporary buffers are created and destroyed, use the buffers command in global configuration mode. To return the buffers to their default size, use the no form of this command.
buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free | min-free | initial} number-of-buffers
no buffers {small | middle | big | verybig | large | huge | type number} {permanent | max-free | min-free | initial} number-of-buffers
Syntax Description
Defaults
The default number of buffers in a pool is determined by the hardware configuration and can be displayed with the show buffers EXEC command.
Command Modes
Global configuration
Command History
Usage Guidelines
Normally you need not adjust these parameters; do so only after consulting with technical support personnel.
Note
You cannot configure FDDI buffers.
Examples
Examples of Public Buffer Pool Tuning
The following example keeps at least 50 small buffers free in the system:
Router(config)# buffers small min-free 50The following example increases the permanent buffer pool allocation for big buffers to 200:
Router(config)# 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.
The following example increases the permanent Ethernet interface 0 buffer pool on a Cisco 4000 router to 96 when the Ethernet 0 buffer pool is depleted:
Router(config)# buffers ethernet 0 permanent 96Related Commands
load-interval
Changes the length of time for which data is used to compute load statistics.
show buffers
Displays statistics for the buffer pools on the network server.
buffers element permanent
To configure the number of permanent buffer elements to prevent packet drop, use the buffers element permanent command in global configuration mode. To reset the number of permanent buffer elements to the default value, use the no form of this command.
buffers element permanent elements
no buffers element permanent
Syntax Description
Defaults
The default number of permanent buffer elements is 500.
Command Modes
Global configuration
Command History
Usage Guidelines
Use the buffers element permanent command to increase the number of permanent buffer elements to prevent packet drop. For example, in a multicasting environment, a higher number of buffer elements may be needed to accommodate bursts of traffic.
Note
Use the show buffers command to display statistics such as free list (the total number of currently unallocated buffer elements), max allowed (the maximum number of buffer elements that are available for allocation), hits (the count of successful attempts to allocate a buffer when needed), misses (the count of buffer allocation attempts that resulted in growing the buffer pool to allocate a buffer), and created (the count of new buffers created to satisfy buffer allocation attempts when the available buffers in the pool have already been allocated).
Note
Examples
The following example configures the number of permanent buffer elements to 6000:
Router(config)# buffers element permanent 6000Related Commands
buffers huge size
To dynamically resize all huge buffers to the value you specify, use the buffers huge size command in global configuration mode. To restore the default buffer values, use the no form of this command.
buffers huge size number-of-bytes
no buffers huge size number-of-bytes
Syntax Description
Defaults
18,024 bytes
Command Modes
Global configuration
Command History
Usage Guidelines
Use this command only after consulting with technical support personnel. The buffer size cannot be lowered below the default.
Note
Examples
The following example resizes huge buffers to 20,000 bytes:
Router(config)# buffers huge size 20000Related Commands
calendar set
To manually set the hardware clock (calendar), use one of the formats of the calendar set command in EXEC mode.
calendar set hh:mm:ss day month year
calendar set hh:mm:ss month day year
Syntax Description
hh:mm:ss
Current time in hours (using 24-hour notation), minutes, and seconds.
day
Current day (by date) in the month.
month
Current month (by name).
year
Current year (no abbreviation).
Command Modes
EXEC
Command History
Usage Guidelines
Some platforms have a hardware clock that is separate from the software clock. In Cisco IOS software syntax, the hardware clock is called the "calendar." The hardware clock is a battery-powered chip that runs continuously, even if the router is powered off or rebooted. After you set the hardware clock, the software clock will be automatically set from the hardware clock when the system is restarted or when the clock read-calendar EXEC command is issued. The time specified in this command is relative to the configured time zone.
Examples
The following example manually sets the hardware clock to 1:32 p.m. on May 19, 2003:
Router# calendar set 13:32:00 May 19 2003Related Commands
cd
To change the default directory or file system, use the cd command in EXEC mode.
cd [filesystem:]
Syntax Description
Defaults
The initial default file system is flash:. For platforms that do not have a physical device named flash:, the keyword flash: is aliased to the default Flash device.
If you do not specify a directory on a file system, the default is the root directory on that file system.
Command Modes
EXEC
Command History
Usage Guidelines
For all EXEC commands that have an optional filesystem argument, the system uses the file system specified by the cd command when you omit the optional filesystem argument. For example, the dir EXEC command, which displays a list of files on a file system, contain an optional filesystem argument. When you omit this argument, the system lists the files on the file system specified by the cd command.
Examples
In the following example, the cd command is used to set the default file system to the Flash memory card inserted in slot 0:
Router# pwdbootflash:/Router# cd slot0:Router# pwdslot0:/Related Commands
cdp advertise-v2
To enable Cisco Discovery Protocol Version 2 (CDPv2) advertising functionality on a device, use the cdp advertise-v2 command in global configuration mode. To disable advertising CDPv2 functionality, use the no form of the command.
cdp advertise-v2
no cdp advertise-v2
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Global configuration
Command History
Usage Guidelines
CDP Version 2 has three additional type-length values (TLVs): VTP Management Domain Name, Native VLAN, and full/half-Duplex.
Examples
In the following example, CDP Version 2 advertisements are disabled on the router:
Router# show cdpGlobal CDP information:Sending CDP packets every 60 secondsSending a holdtime value of 180 secondsSending CDPv2 advertisements is enabledRouter# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# no cdp advertise-v2Router(config)# endRouter# show cdpGlobal CDP information:Sending CDP packets every 60 secondsSending a holdtime value of 180 secondsSending CDPv2 advertisements is not enabledRouter#Related Commands
cdp enable
Enables CDP on a supported interface.
cdp run
Reenables CDP on a Cisco device.
cdp enable
To enable Cisco Discovery Protocol (CDP) on an interface, use the cdp enable command in interface configuration mode. To disable CDP on an interface, use the no form of this command.
cdp enable
no cdp enable
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled at the global level and on all supported interfaces.
Command Modes
Interface configuration
Command History
Usage Guidelines
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
Examples
In the following example, CDP is disabled on the Ethernet 0 interface only:
Router# show cdpGlobal CDP information:Sending CDP packets every 60 secondsSending a holdtime value of 180 secondsSending CDPv2 advertisements is enabledRouter# config terminalRouter(config)# interface ethernet 0Router(config-if)# no cdp enableRelated Commands
cdp run
Reenables CDP on a Cisco device.
cdp timer
Specifies how often the Cisco IOS software sends CDP updates.
router odr
Enables on-demand routing on a hub router.
cdp holdtime
To specify the amount of time the receiving device should hold a Cisco Discovery Protocol (CDP) packet from the router before discarding it, use the cdp holdtime command in global configuration mode. To revert to the default setting, use the no form of this command.
cdp holdtime seconds
no cdp holdtime
Syntax Description
Defaults
180 seconds
Command Modes
Global configuration
Command History
Usage Guidelines
CDP packets are sent with a time to live, or hold time, value. The receiving device will discard the CDP information in the CDP packet after the hold time has elapsed.
You can set the hold time lower than the default setting of 180 seconds if you want the receiving devices to update their CDP information more rapidly.
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.
Examples
In the following example, the CDP packets being sent from the router are configured with a hold time of 60 seconds.
Router(config)# cdp holdtime 60Related Commands
cdp timer
Specifies how often the Cisco IOS software sends CDP updates.
show cdp
Displays global CDP information, including timer and hold-time information.
cdp log mismatch duplex
To display the log of duplex mismatches generated by the Cisco Discovery Protocol (CDP) on Ethernet interfaces on a router, use the cdp log mismatch duplex command in global configuration or interface configuration mode. To disable the display of duplex messages on all Ethernet interfaces, use the no form of this command.
cdp log mismatch duplex
no cdp log mismatch duplex
Syntax Description
This command has no arguments or keywords.
Defaults
The router reports duplex mismatches from all Ethernet interfaces.
Command Modes
Global configuration
Interface configurationCommand History
Usage Guidelines
When you enter the cdp log mismatch duplex command in global configuration mode, duplex mismatches are displayed on all Ethernet interfaces on the router. When you enter this command in interface configuration mode, only duplex mismatches for the specified Ethernet interface are displayed.
If the cdp log mismatch duplex command is disabled in global configuration mode, it cannot be configured per interface using interface configuration mode.
Duplex mismatch can occur only on Ethernet interfaces.
Examples
The following example of the cdp log mismatch duplex command in global configuration mode enables the display of duplex messages from all Ethernet interfaces on the router:
Router(config)# cdp log mismatch duplexThe following example of the cdp log mismatch duplex command in interface configuration mode enables only the display of duplex messages that may be generated from Ethernet interface 2/1:
Router(config-if)# interface ethernet2/1Router(config-if)# cdp log mismatch duplexThe following is sample output from the show running-config command. The bold text shows that the cdp log mismatch duplex command is disabled globally.
Router# show running-configBuilding configuration...Current configuration : 1395 bytes!version 12.2!hostname 7200_C!!interface Ethernet2/1no ip addressduplex halfno cdp log mismatch duplex!!!!!no cdp log mismatch duplexcdp timer 5!!!!line con 0line aux 0line vty 0 4password labRelated Commands
show running-config
Displays the contents of the currently running configuration file.
cdp run
To enable Cisco Discovery Protocol (CDP), use the cdp run command in global configuration mode. To disable CDP, use the no form of this command.
cdp run
no cdp run
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Global configuration
Command History
Usage Guidelines
CDP is enabled 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
Examples
In the following example, CDP is disabled globally, then the user attempts to enable CDP on the Ethernet 0 interface:
Router(config)# no cdp runRouter(config)# endRouter# show cdp% CDP is not enabledRouter# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# int eth0Router(config-if)# cdp enable% Cannot enable CDP on this interface, since CDP is not runningRouter(config-if)#Related Commands
cdp enable
Enables CDP on a supported interface.
cdp timer
Specifies how often the Cisco IOS software sends CDP updates.
router odr
Enables ODR on the hub router.
cdp source-interface
To configure the Cisco Discovery Protocol source interface, use the cdp source-interface command in global configuration mode.
cdp source-interface type number
no cdp source-interface
Syntax Description
Defaults
No Cisco Discovery Protocol source-interface is specified.
Command Modes
Global configuration
Command History
Usage Guidelines
Use of this command ensures that Cisco Discovery Protocol packets use the IP address that has been previously assigned to an interface. Without this command, Cisco Discovery Protocol uses the IP address of the first available interface.
The conditions that an interface should satisfy to be the source interface are as follows:
•
•
•
When Cisco Discovery Protocol is enabled and the Cisco Discovery Protocol source interface has not been configured, then Cisco Discovery Protocol uses the IP address of the first available interface.
Examples
The following example configures Cisco Discovery Protocol to use the IP address that has been assigned to interface loopback 1.
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# cdp source-interface loopback 1Router(config)# exitRouter#Related Commands
cdp enable
Enables Cisco Discovery Protocol on a supported interface.
cdp run
Reenables Cisco Discovery Protocol on a Cisco device.
cdp timer
To specify how often the Cisco IOS software sends Cisco Discovery Protocol (CDP) updates, use the cdp timer command in global configuration mode. To revert to the default setting, use the no form of this command.
cdp timer seconds
no cdp timer
Syntax Description
Defaults
60 seconds
Command Modes
Global configuration
Command History
Usage Guidelines
The trade-off with sending more frequent CDP updates to provide up-to-date information, is that bandwidth is used more often.
Note
Examples
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 Cisco Discovery Protocol (CDP) traffic counters to zero, use the clear cdp counters command in privileged EXEC mode.
clear cdp counters
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following example clears the CDP counters. The show cdp traffic output shows that all of the traffic counters have been reset to zero.
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
Clears the table that contains CDP information about neighbors.
show cdp traffic
Displays traffic information from the CDP table.
clear cdp table
To clear the table that contains Cisco Discovery Protocol (CDP) information about neighbors, use the clear cdp table command in privileged EXEC mode.
clear cdp table
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
The following example clears the CDP table. 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 cns config stats
To clear the statistics about the CNS configuration agent, use the clear cns config stats command in privileged EXEC mode.
clear cns config stats
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear cns config stats command clears all the statistics displayed by the show cns config stats command.
Examples
The following example shows how to clear all of the statistics for the CNS configuration agent:
Router# clear cns config statsRelated Commands
clear cns counters
To clear all CNS statistics, use the clear cns counters command in privileged EXEC mode.
clear cns counters
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear cns counters command clears all the statistics tracked and displayed by CNS agents.
Examples
The following example shows how to clear all of the statistics used by CNS:
Router# clear cns countersRelated Commands
clear cns event stats
To clear the statistics about the CNS event agent, use the clear cns event stats command in privileged EXEC mode.
clear cns event stats
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear cns event stats command clears all the statistics displayed by the show cns event stats command.
Examples
The following example shows how to clear all of the statistics for the CNS event agent:
Router# clear cns event statsRelated Commands
clear cns image connections
To clear the CNS image agent connections statistics, use the clear cns image connections command in privileged EXEC mode.
clear cns image connections
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear cns image connections command clears all the statistics displayed by the show cns image connections command.
Examples
The following example shows how to clear all of the connection statistics for the CNS image agent:
Router# clear cns image connectionsRelated Commands
show cns image connections
Displays connection information for the CNS image agent.
clear cns image status
To clear the CNS image agent status statistics, use the clear cns image status command in privileged EXEC mode.
clear cns image status
Syntax Description
This command has no arguments or keywords.
Defaults
No statistics are cleared.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear cns image status command clears all the statistics displayed by the show cns image status command.
Examples
The following example shows how to clear all of the status statistics for the CNS image agent:
Router# clear cns image statusRelated Commands
clear logging
To clear messages from the logging buffer, use the clear logging command in privileged EXEC mode.
clear logging
Syntax Description
This command has no arguments or keywords.
Command Modes
Privileged EXEC
Command History
Examples
In the following example, the logging buffer is cleared:
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).
clear logging xml
To clear the contents of the XML system message logging (syslog) buffer, use the clear logging xml command in User EXEC or Priviledged EXEC mode..
clear logging xml
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
User EXEC
Privileged EXEC
Command History
Usage Guidelines
This command clears the contents of the XML-formatted logging buffer, but does not clear the contents of the standard logging buffer. The system will prompt you to confirm the action before clearing the buffer.
Examples
In the following example, the XML-specific buffer is cleared:
Router# clear logging xmlClear XML logging buffer [confirm]?yRelated Commands
clear parser cache
To clear the parse cache entries and hit/miss statistics stored for the Parser Cache feature, use the clear parser cache command in privileged EXEC mode.
clear parser cache
Syntax Description
This command has no arguments or keywords.
Defaults
No default behavior or values.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The Parser Cache feature optimizes the parsing (translation and execution) of Cisco IOS software configuration command lines by remembering how to parse recently encountered command lines, decreasing the time required to process large configuration files.
The clear parser cache command will free the system memory used by the Parser Cache feature and will erase the hit/miss statistics stored for the output of the show parser statistics EXEC command. This command is only effective when the Parser Cache feature is enabled.
Examples
The following example shows the clearing of the parser cache:
Router# show parser statisticsLast configuration file parsed:Number of Commands:1484, Time:820 msParser cache:enabled, 1460 hits, 26 missesRouter# clear parser cacheRouter# show parser statisticsLast configuration file parsed:Number of Commands:1484, Time:820 msParser cache:enabled, 0 hits, 1 missesRelated Commands
clear saa apm cache
To delete files from the SAA Application Performance Monitor (APM) cache, use the clear saa apm cache command in global configuration mode.
clear saa apm cache {local | remote | file filename} [force]
Syntax Description
Defaults
No default behavior or values.
Command Modes
Global configuration
Command History
Usage Guidelines
This command will not delete files tagged as "sticky" in the APM cache unless the force keyword is used. The sticky bit is set for a file when the file is copied to the router using the saa apm copy command. To check if files have the sticky bit set, use the show saa apm cache command; those files that show a value of 1 in the "SBit" column have the sticky bit enabled, while those with a sticky value of 0 do not have the sticky bit enabled.
Examples
In the following example, all files that are not tagged as "sticky" (as seen in the SBit column of the show saa apm cache output) are deleted from the APM cache:
Router# show saa apm cacheCache Size (bytes):100000Cache used (bytes):2056TimeCreated TimeAccessed Size Ref Loc Type SBit FileName09/21 13:31:25 09/21 13:31:48 1170 0 1 SCR 0 user/scripts/ldap-rem.scr09/21 13:31:20 09/21 13:31:27 1513 0 1 SCR 1 user/scripts/ldap.scr09/20 14:29:13 09/20 14:29:36 735 0 1 SCR 0 user/scripts/udp-rem.scrRouter# configure terminalRouter(config)# clear saa apm cache localRouter(config)# endRouter# show saa apm cacheCache Size (bytes):100000Cache used (bytes):1513TimeCreated TimeAccessed Size Ref Loc Type SBit FileName09/21 13:31:20 09/21 13:31:27 1513 0 1 SCR 1 user/scripts/ldap.scrRelated Commands
show saa apm cache
Displays the amount of memory available in the SAA APM cache and information about the files stored in the cache.
clear tcp
To clear a TCP connection, use the clear tcp command in privileged EXEC mode.
clear tcp {line line-number | local hostname port remote hostname port | tcb address}
Syntax Description
Command Modes
Privileged EXEC
Command History
Usage Guidelines
The clear tcp command is particularly useful for clearing hung TCP connections.
The clear tcp line line-number command terminates the TCP connection on the specified tty line. Additionally, all TCP sessions initiated from that tty line are terminated.
The clear tcp local hostname port remote hostname port command terminates the specific TCP connection identified by the host name and port pair of the local and remote router.
The clear tcp tcb address command terminates the specific TCP connection identified by the TCB address.
Examples
The following example clears a TCP connection using its tty line number. The show tcp command displays the line number (tty2) that is used in the clear tcp command.
Router# show tcptty2, virtual tty from host router20.cisco.comConnection state is ESTAB, I/O status: 1, unread input bytes: 0Local host: 171.69.233.7, Local port: 23Foreign host: 171.69.61.75, Foreign port: 1058Enqueued packets for retransmit: 0, input: 0, saved: 0Event Timers (current time is 0x36144):Timer Starts Wakeups NextRetrans 4 0 0x0TimeWait 0 0 0x0AckHold 7 4 0x0SendWnd 0 0 0x0KeepAlive 0 0 0x0GiveUp 0 0 0x0PmtuAger 0 0 0x0iss: 4151109680 snduna: 4151109752 sndnxt: 4151109752 sndwnd: 24576irs: 1249472001 rcvnxt: 1249472032 rcvwnd: 4258 delrcvwnd: 30SRTT: 710 ms, RTTO: 4442 ms, RTV: 1511 ms, KRTT: 0 msminRTT: 0 ms, maxRTT: 300 ms, ACK hold: 300 msRouter# clear tcp line 2[confirm][OK]The following example clears a TCP connection by specifying its local router host name and port and its remote router host name and port. The show tcp brief command displays the local (Local Address) and remote (Foreign Address) host names and ports to use in the clear tcp command.
Router# show tcp briefTCB Local Address Foreign Address (state)60A34E9C router1.cisco.com.23 router20.cisco.1055 ESTABRouter# clear tcp local router1 23 remote router20 1055[confirm][OK]The following example clears a TCP connection using its TCB address. The show tcp brief command displays the TCB address to use in the clear tcp command.
Router# show tcp briefTCB Local Address Foreign Address (state)60B75E48 router1.cisco.com.23 router20.cisco.1054 ESTABRouter# clear tcp tcb 60B75E48[confirm][OK]Related Commands
show tcp
Displays the status of TCP connections.
show tcp brief
Displays a concise description of TCP connection endpoints.
clear xsm
To clear XML Subscription Manager (XSM) client sessions, use the clear xsm command in privileged EXEC mode.
clear xsm [session number]
Syntax Description
session number
(Optional) XSM session ID number of the specific XSM client session you wish to clear.
Defaults
If the optional session number syntax is not used, the clear xsm command clears all XSM client sessions.
Command Modes
Privileged EXEC
Command History
Usage Guidelines
This command disconnects all active client sessions (such as with a VPN Device Manager [VDM]) on the XSM server, unless you state a specific session number. This command allows troubleshooting of the XSM server and its active clients by allowing individual clients to be disconnected. Use the show xsm status command to obtain specific session numbers.
Examples
In the following example, all XSM client sessions are cleared:
Router# clear xsmIn the following example, XSM client session 10 is cleared:
Router# clear xsm session 10Related Commands
show xsm status
Displays information and status about clients subscribed to the XSM server.
xsm
Enables XSM client access to the router.
cli
To specify EXEC command line interface (CLI) commands within a Command Scheduler policy list, use the cli command in kron-policy configuration mode. To delete a CLI command from the current policy list, use the no form of this command.
cli command
no cli command
Syntax Description
command
EXEC mode CLI command syntax. Commands must not generate a prompt or allow interruption by any keystroke.
Defaults
No CLI commands are specified.
Command Modes
Kron-policy configuration (config-kron-policy)
Command History
Usage Guidelines
Use the cli command in conjunction with the kron policy-list command to create a policy list containing EXEC CLI commands to be scheduled to run on the router at a specified time. Use the kron occurrence and policy-list commands to schedule one or more policy lists to run at the same time or interval.
The Command Scheduler process is useful to automate the running of EXEC commands at recurring intervals, and it can be used in remote routers to minimize manual intervention.
Examples
The following example shows how to configure the EXEC command cns image retrieve within the policy list named three-day-list:
Router(config)# kron policy-list three-day-listRouter(config-kron-policy)# cli cns image retrieve server https://10.19.2.3/cns/image/ status https://10.19.2.3/cnsstatus/imageinfo/Related Commands
cli (cns)
To specify the command lines of a Cisco Networking Services (CNS) connect template, use the cli command in CNS template connect configuration mode. To disable this configuration, use the no form of this command.
cli config-text
no cli config-text
Syntax Description
Defaults
No command lines are specified in the CNS connect template.
Command Modes
CNS template connect configuration
Command History
Usage Guidelines
First use the cns template connect command to enter CNS template connect configuration mode and define the name of the CNS connect template to be configured. Then use the cli command to specify the command lines of the CNS connect template.
Note
The command lines specified using the cli command can include CNS connect variables (see Table 12). These variables act as placeholders within the command lines of a CNS connect template. Each variable is defined by an associated discover command. Before a CNS connect template that contains these variables is applied to a router's configuration, the variables are replaced by the values defined by their associated discover command. For example, if the discover interface serial command was configured, and you were able to connect to the CNS configuration engine using Serial0/0, then the cli ip route 0.0.0.0 0.0.0.0 ${interface} command would generate the cli ip route 0.0.0.0 0.0.0.0 serial0/0 command.
Note
Note
Examples
The following example shows how to configure a CNS connect template named template1:
Router (config)# cns template connect template-1Router (config-templ-conn)# cli command-1Router (config-templ-conn)# cli command-2Router (config-templ-conn)# cli no command-3Router (config-templ-conn)# exitRouter (config)#When the template1 template is applied, the following commands are sent to the router's parser:
command-1command-2no command-3When the template1 template is removed from the router's configuration after an unsuccessful ping attempt to the CNS configuration engine, the following commands are sent to the router's parser:
no command-1no command-2command-3Related Commands
clock calendar-valid
To configure a system as an authoritative time source for a network based on its hardware clock (calendar), use the clock calendar-valid command in global configuration mode. To specify that the hardware clock is not an authoritative time source, use the no form of this command.
clock calendar-valid
no clock calendar-valid
Syntax Description
This command has no arguments or keywords.
Defaults
The router is not configured as a time source.
Command Modes
Global configuration
Command History
Usage Guidelines
Some platforms have a hardware clock that is separate from the software clock. The hardware clock runs continuously, even if the router is powered off or rebooted. If no outside time source is available on your network, use this command to make the hardware clock an authoritative time source.
Because the hardware clock is not as accurate as other time sources, you should configure this command only when a more accurate time source (such as NTP) is not available.
Examples
The following example configures a router as the time source for a network based on its hardware clock:
Router(config)# clock calendar-validRelated Commands
clock read-calendar
To manually read the hardware clock (calendar) settings into the software clock, use the clock read-calendar command in EXEC mode.
clock read-calendar
Syntax Description
This command has no arguments or keywords.
Command Modes
EXEC
Command History
Usage Guidelines
Some platforms have a hardware clock that is separate from the software clock. The hardware clock runs continuously, even if the router is powered off or rebooted. When the router is rebooted, the hardware clock is automatically read into the software clock. However, you may use this command to manually read the hardware clock setting into the software clock. This command is useful if the calendar set command has been used to change the setting of the hardware clock.
Examples
The following example configures the software clock to set its date and time by the hardware clock setting:
Router> clock read-calendarRelated Commands
clock set
To manually set the system software clock, use one of the following formats of the clock set command in privileged EXEC mode.
clock set hh:mm:ss day month year
clock set hh:mm:ss month day year
Syntax Description
hh:mm:ss
Current time in hours (24-hour format), minutes, and seconds.
day
Current day (by date) in the month.
month
Current month (by name).
year
Current year (no abbreviation).
Command Modes
Privileged EXEC mode
Command History
Usage Guidelines
Generally, if the system is synchronized by a valid outside timing mechanism, such as a Network Time Protocol (NTP) or VINES clock source, or if you have a router with hardware clock, you need not set the software clock. Use this command if no other time sources are available. The time specified in this command is assumed to be in the timezone specified by the configuration of the clock timezone command.
Examples
The following example manually sets the software clock to 7:29 p.m. on May 13, 2003:
Router# clock set 19:29:00 13 May 2003Related Commands
clock summer-time
To configure the system to automatically switch to summer time (daylight saving time), use one of the formats of the clock summer-time command in global configuration mode. To configure the Cisco IOS software not to automatically switch to summer time, use the no form of this command.
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-time
Syntax Description
Defaults
Summer time is disabled. If the clock summer-time zone recurring command is specified without parameters, the summer time rules default to United States rules. Default of the offset argument is 60.
Command Modes
Global configuration
Command History
Usage Guidelines
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 keyword to specify a start and end date for summer time if you cannot use the recurring keyword.
In both the date and recurring 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 chronologically after the ending month, the system assumes that you are in the southern hemisphere.
Examples
The following example specifies that summer time starts on the first Sunday in April at 2 a.m. and ends on the last Sunday in October at 2 a.m.:
Router(config)# 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 can specify the exact date and times. In the following example, daylight saving time (summer time) is configured to start on October 12, 1997 at 2 a.m., and end on April 26, 1998 at 2 a.m.:
Router(config)# clock summer-time date 12 October 1997 2:00 26 April 1998 2:00Related Commands
calendar set
Sets the hardware clock.
clock timezone
Sets the time zone for display purposes.
clock timezone
To set the time zone for display purposes, use the clock timezone command in global configuration mode. To set the time to Coordinated Universal Time (UTC), use the no form of this command.
clock timezone zone hours-offset [minutes-offset]
no clock timezone
Syntax Description
Defaults
UTC
Command Modes
Global configuration
Command History
Usage Guidelines
The system internally keeps time in UTC, so this command is used only for display purposes and when the time is manually set.
Table 13 lists common time zone acronyms used for the zone argument.
Table 14lists an alternative method for referring to time zones, in which single letters are used to refer to the time zone difference from UTC. Using this method, the letter Z is used to indicate the zero meridian, equivalent to UTC, and the letter J (Juliet) is used to refer to the local time zone. Using this method, the International Date Line is between time zones M and Y.
The following example sets the time zone to Pacific Standard Time (PST), which is 8 hours behind UTC:
Router(config)# clock timezone PST -8The following example sets the time zone to Atlantic Time (AT) for Newfoundland, Canada, which is 3.5 hours behind UTC:
Router(config)# clock timezone AT -3 30Related Commands
