Table Of Contents
Using the Command Line Interface
Subinterface Configuration Mode
Access-List Configuration Mode
IBM Channel Attach Command Modes
LANE Database Configuration Mode
Response Time Reporter Configuration Mode
Summary of Configuration Command Modes
Using the No and Default Forms of Commands
Example of Context Sensitive Help
Display Help for All User-Level Commands
Use the Command History Features
Set the Command History Buffer Size
Disable the Command History Feature
Move Around on the Command Line
Complete a Partial Command Name
Scroll Down a Line or a Screen
Redisplay the Current Command Line
Designate a Keystroke as a Command Entry
Specify the Underlying Command for the Menu Item
Specify the Default Command for the Menu
Specify Menu Display Configuration Options
Displaying Single-Spaced Menus
Displaying an Informational Status Line
Delete the Menu from the Configuration
Use the Cisco Web Browser Interface to Issue Commands
Cisco Web Browser Interface Task List
Configure the Cisco Web Browser Interface
Enable the Cisco Web Browser Interface
Change the Cisco Web Browser Interface Port Number
Control Access to the Cisco Web Browser Interface
Specify the Method for User Authentication
Use the Correct Hardware and Software
Access Your Router's Home Page
Issue Commands Using the Cisco Web Browser Interface
Enter Commands Using Hypertext Links
Enter Commands Using the Command Field
Enter Commands Using the URL Window
Customize the User Interface on a Web Browser
Benefits of Customizing Web Pages with SSIs
User Interface Customization Task List
Customize HTML Pages Using SSIs
Copy HTML Pages to Flash Memory
Enable the Cisco Web Browser Interface
View Your HTML File Containing SSIs
Display 8-bit and Multibyte Character Sets
Using the Command Line Interface
Cisco IOS commands can be entered at a terminal connected to the access server or router using the command line interface (CLI). Commands may also be entered using the Cisco Web browser interface. This chapter describes how to use the Cisco IOS command line interface and Web page interface. It describes command modes, help features, command editing and history features, and menus.
For a complete description of the user interface commands in this chapter, refer to the "Basic Command Line Interface Commands" chapter of the Configuration Fundamentals Command Reference. To locate documentation of specific commands, use the command reference index or search online.
User Interface Task List
You can perform the tasks in the following sections to familiarize yourself with the Cisco IOS user interface. If you are not familiar with the Cisco IOS command line interface, read the first six sections to gain a basic understanding of the user interface.
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Using the No and Default Forms of Commands
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Access Each Command Mode
The Cisco IOS user interface is divided into many different modes. The commands available to you at any given time depend on which mode you are currently in. Entering a question mark (?) at the system prompt allows you to obtain a list of commands available for each command mode.
When you start a session on the router, you begin in user mode, often called EXEC mode. Only a limited subset of the commands are available in EXEC mode. In order to have access to all commands, you must enter privileged EXEC mode. Normally, you must enter a password to enter privileged EXEC mode. From privileged mode, you can enter any EXEC command or enter global configuration mode. Most of the EXEC commands are one-time commands, such as show commands, which show the current status of something, and clear commands, which clear counters or interfaces. The EXEC commands are not saved across reboots of the router.
The configuration modes allow you to make changes to the running configuration. If you later save the configuration, these commands are stored across router reboots. In order to get to the various configuration modes, you must start at global configuration mode. From global configuration mode, you can enter interface configuration mode, subinterface configuration mode, and a variety of protocol-specific modes.
ROM monitor mode is a separate mode used when the router cannot boot properly. If your router or access server does not find a valid system image when it is booting, or if its configuration file is corrupted at startup, the system might enter read-only memory (ROM) monitor mode.
The following sections describe how to access each of the Cisco IOS command modes:
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User EXEC Mode
After you log in to the router or access server, you are automatically in user EXEC command mode. The EXEC commands available at the user level are a subset of those available at the privileged level. In general, the user EXEC commands allow you to connect to remote devices, change terminal settings on a temporary basis, perform basic tests, and list system information.
To list the user EXEC commands, complete the following task:
The user-level prompt consists of the host name followed by the angle bracket (>):
Router>The default host name is Router unless it has been changed during initial configuration using the setup command. Refer to the product user guide for information on the setup facility. You can also change the host name using the hostname global configuration command described in the "Basic System Management Commands" chapter in the Configuration Fundamentals Command Reference.
To list the commands available in user EXEC mode, enter a question mark (?) as shown in the following example:
Router> ?Exec commands:<1-99> Session number to resumeconnect Open a terminal connectiondisconnect Disconnect an existing telnet sessionenable Turn on privileged commandsexit Exit from the EXEChelp Description of the interactive help systemlat Open a lat connectionlock Lock the terminallogin Log in as a particular userlogout Exit from the EXECmenu Start a menu-based user interfacembranch Trace multicast route for branch of treemrbranch Trace reverse multicast route to branch of treemtrace Trace multicast route to groupname-connection Name an existing telnet connectionpad Open a X.29 PAD connectionping Send echo messagesresume Resume an active telnet connectionshow Show running system informationsystat Display information about terminal linestelnet Open a telnet connectionterminal Set terminal line parameterstn3270 Open a tn3270 connectiontrace Trace route to destinationwhere List active telnet connectionsx3 Set X.3 parameters on PADxremote Enter XRemote modeThe list of commands might vary slightly from this example, depending on the software feature set and configuration of your Cisco routing product.
Privileged EXEC Mode
Because many of the privileged commands set operating parameters, privileged access should be password protected to prevent unauthorized use. The privileged command set includes those commands contained in user EXEC mode, as well as the configure command through which you can access the remaining command modes. Privileged EXEC mode also includes high-level testing commands, such as debug. For details on the debug commands, see the Debug Command Reference.
The privileged EXEC mode prompt consists of the devices's host name followed by the pound sign (#). (If the router or access server was named with the hostname command, that name would appear as the prompt instead of "Router.")
Router#To access and list the privileged EXEC commands, complete the following tasks:
Step 1
enable
[password]Step 2
?
To return from privileged EXEC mode to user EXEC mode, perform the following task:
If the system administrator has set a password, you are prompted to enter it before being allowed access to privileged EXEC mode. The password is not displayed on the screen and is case sensitive. If an enable password has not been set, enable mode can be accessed only from the router console. The system administrator uses the enable password global configuration command to set the password that restricts access to privileged mode. This command is described in the "Passwords and Privileges Commands" chapter in the Security Command Reference.
The following example shows how to access privileged EXEC mode:
Router> enablePassword:Router#From the privileged level, you can access global configuration mode. For instructions, see the "Global Configuration Mode" section, which follows this section.
Global Configuration Mode
Global configuration commands apply to features that affect the system as a whole, rather than just one protocol or interface. Use the configure terminal privileged EXEC command to enter global configuration mode.
Commands to enable a particular routing or bridging function are also global configuration commands. For information on protocol-specific global configuration commands, see the appropriate configuration guide in the Cisco IOS software documentation.
To access and list the global configuration commands, complete the following tasks:
Step 1
configure terminal
Step 2
?
The following example shows how to access global configuration mode:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)#To exit global configuration command mode and return to privileged EXEC mode, use one of the following commands:
From global configuration mode, you can access a number of other command modes. These command modes are described in the sections that follow. For a complete list of these modes, see the section "Other Configuration Modes."
Interface Configuration Mode
Many features are enabled on a per-interface basis. Interface configuration commands modify the operation of an interface such as an Ethernet, FDDI, or serial port. Interface configuration commands always follow an interface global configuration command, which defines the interface type.
For details on interface configuration commands that affect general interface parameters, such as bandwidth, clock rate, and so on, see the "Interface Commands" chapter in the Configuration Fundamentals Command Reference. For protocol-specific commands, see the appropriate Cisco IOS software command reference.
To access and list the interface configuration commands, complete the following tasks:
Step 1
interface type number
Step 2
?
In the following example, serial interface 0 is about to be configured. The new prompt
Router(config-if)# indicates interface configuration mode.Router(config)# interface serial 0 <CR>Router(config-if)#To exit interface configuration mode and return to global configuration mode, enter the exit command. To exit configuration mode and return to privileged EXEC mode, use the end command or press Ctrl-Z.
Subinterface Configuration Mode
You can configure multiple virtual interfaces (called subinterfaces) on a single physical interface. Subinterfaces appear to be distinct physical interfaces to the various protocols. For example, Frame Relay networks provide multiple point-to-point links called permanent virtual circuits (PVCs). PVCs can be grouped under separate subinterfaces that in turn are configured on a single physical interface. From a bridging spanning-tree viewpoint, each subinterface is a separate bridge port, and a frame arriving on one subinterface can be sent out on a another subinterface.
Subinterfaces also allow multiple encapsulations for a protocol on a single interface. For example, a router or access server can receive an ARPA-framed IPX packet and forward the packet back out the same physical interface as a SNAP-framed IPX packet.
For detailed information on how to configure subinterfaces, see the appropriate module for a specific protocol in the Cisco IOS software documentation.
To access and list the subinterface configuration commands, complete the following tasks:
In the following example, a subinterface is configured for serial line 2, which is configured for Frame Relay encapsulation. The subinterface is called 2.1 to indicate that it is subinterface 1 of serial interface 2. The new prompt Router(config-subif)# indicates that you are in subinterface configuration mode. The subinterface can be configured to support one or more Frame Relay PVCs.
Router(config)# interface serial 2Router(config-if)# encapsulation frame-relayRouter(config-if)# interface serial 2.1Router(config-subif)#To exit subinterface configuration mode and return to global configuration mode, enter the exit command. To exit configuration mode and return to privileged EXEC mode, press Ctrl-Z.
ROM Monitor Mode
If your router or access server does not find a valid system image, or if you interrupt the boot sequence, the system might enter read-only memory (ROM) monitor mode. From ROM monitor mode, you can boot the device or perform diagnostic tests.
You can also enter ROM monitor mode by entering the reload EXEC command and then pressing the Break key during the first 60 seconds of startup. If you have changed the configuration, use the copy running-config startup-config command and then issue the reload command to save your configuration changes.
To access and list the ROM monitor configuration commands, complete the following tasks:
Enter ROM monitor mode from privileged EXEC mode.
reload
Press the Break key during the first 60 seconds while the system is booting.List the ROM monitor commands.
?
The ROM monitor prompt is the angle bracket (>):
> ?$ state Toggle cache state (? for help)B [filename] [TFTP Server IP address | TFTP Server Name]Load and execute system image from ROM or from TFTP serverC [address] Continue execution [optional address]D /S M L V Deposit value V of size S into location L with modifier ME /S M L Examine location L with size S with modifier MG [address] Begin executionH Help for commandsI InitializeK Stack traceL [filename] [TFTP Server IP address | TFTP Server Name]Load system image from ROM or from TFTP server, but do notbegin executionO Show configuration register option settingsP Set the break pointS Single step next instructionT function Test device (? for help)Deposit and Examine sizes may be B (byte), L (long) or S (short).Modifiers may be R (register) or S (byte swap).Register names are: D0-D7, A0-A6, SS, US, SR, and PCTo return to user EXEC mode, type continue. To initialize the router or access server, enter the i command. The i command causes the bootstrap program to reinitialize the hardware, clear the contents of memory, and boot the system. (It is best to issue the i command before you run any tests or boot software.) To boot the system image file, use the b command (see the "Rebooting a Router" chapter). For details on ROM monitor mode commands, refer to the appropriate hardware installation guide.
Summary of Main Command Modes
summarizes the main command modes of the Cisco IOS software.
Other Configuration Modes
The following sections describe the other configuration modes:
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Most of these modes can be entered from global configuration mode. In these modes, the exit command returns you to the global configuration mode. Other modes must be entered from another configuration mode. Entering the exit command in one of these modes returns you to the configuration mode you used to enter the mode.
In any configuration mode, to enter privileged EXEC mode and leave configuration mode entirely, use the end command or press Ctrl-Z.
in the "Summary of Configuration Command Modes" section lists how to enter each mode.
Access-List Configuration Mode
All IP and IPX access lists can be identified by a number. Alternatively, some IP and IPX access lists can be identified by a name. Use access-list configuration mode when you are creating a named IP or IPX access list.
For information on creating a named IP access list, refer to the "Configuring IP Services" chapter in the Network Protocols Configuration Guide, Part 1. For information on creating a named IPX access list, refer to the "Configuring Novell IPX" chapter in the Network Protocols Configuration Guide, Part 2.
APPN Command Modes
Advanced Peer-to-Peer Networking (APPN) is the second generation of SNA. APPN provides support for client/server applications and offers more dynamics than traditional hierarchical SNA, such as dynamic directory and routing services.
APPN allows you to define attributes of the APPN network that can become quite complex. To easily manage the details of APPN, special configuration command modes and conventions have been developed.
Because APPN offers a large number of configuration options, specific configuration dialogs are used for each major APPN configuration item. When you define the major item, you will automatically enter the detailed configuration mode for that item. There are two options to exit the detailed configuration mode. Use the complete command to exit the detailed configuration mode and update the APPN subsystem with the changes. Use the exit command to leave the definition in "no complete" state without updating the APPN subsystem.
Refer to the "APPN Configuration Commands" chapter in the Bridging and IBM Networking Command Reference for information on the following APPN modes:
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Controller Configuration Mode
You can configure channelized T1 in the controller configuration mode. Refer to the "Configuring Channelized E1 and Channelized T1" chapter in the Dial Solutions Configuration Guide for more information.
Crypto Map Configuration Mode
Use crypto map configuration mode to create or alter the definition of a crypto-map. Crypto-maps are part of an authentication/encryption router configuration. For more information, refer to the "Network Data Encryption Commands" chapter in the Security Command Reference.
Hex Input Mode
Use hex input mode to enter a public key for an encrypting peer router. The public key data is entered in hexadecimal form, and it will take more than one command line to enter. To continue entering the public key data on a new line, press Return. When the public key is completely entered, press Return to get a new line, then type quit to return to the global configuration mode. For more information, refer to the "Network Data Encryption Commands" chapter in the Security Command Reference.
Hub Configuration Mode
Hub configuration commands configure hub functionality for an Ethernet interface on the Cisco 2500. They always follow a hub global configuration command. Refer to the "Configuring LAN Interfaces" chapter in this publication and the "Interface Commands" chapter in the Configuration Fundamentals Command Reference.
IBM Channel Attach Command Modes
The Channel Interface Processor (CIP) supports the IBM channel attach feature. This configuration is an ideal connectivity hub for large corporate networks that provide routing services between mainframes and LANs.
Interface Channel Configuration Mode
Before you configure your channel attach interface, you must select an interface. The following mode is valid only for port 2 on a CIP board. Ports 0 and 1 represent real, physical ports. Port 2 is an internal, virtual port. Refer to the "IBM Channel Attach Commands" chapter in the Bridging and IBM Networking Command Reference.
Internal LAN Configuration Mode
Use the IBM channel internal LAN configuration mode to configure an internal LAN on a CIP interface and configure Cisco Systems Network Architecture (CSNA) parameters. Refer to the "IBM Channel Attach Commands" chapter in the Bridging and IBM Networking Command Reference.
Internal Adapter Configuration Mode
Internal adapter commands allow you to configure the link characteristics for the internal LAN adapter and name the internal LAN adapter. Refer to the "IBM Channel Attach Commands" chapter in the Bridging and IBM Networking Command Reference.
To configure an internal adapter interface, you must first use the bridge-group internal LAN configuration command or the source-bridge internal LAN configuration command to configure bridging type. These commands are documented in the "Source-Route Bridging Commands" chapter of the Bridging and IBM Networking Command Reference.
IPX-Router Configuration Mode
Internet Packet Exchange (IPX) is a Novell network-layer protocol. The IPX-router configuration mode is used to configure IPX routing. Refer to the "Novell IPX Commands" chapter in the Network Protocols Command Reference, Part 2
Key Chain Configuration Mode
From key chain configuration mode, you can manage authentication keys. For details on how to use key chain configuration commands, consult the "Configuring IP Routing Protocol-Independent Features" chapter of the Network Protocols Configuration Guide, Part 1.
Key management controls the authentication keys that routing protocols use. To enter key chain configuration mode, identify or define a key chain using the keychain command. From key chain configuration mode, you can identify or define key numbers.
Key Chain Key Configuration Mode
Once you define a key chain, use the key chain key configuration mode to configure the keys on the key chain. Refer to the "IP Routing Protocol-Independent Commands" chapter in the Network Protocols Command Reference, Part 1.
LANE Database Configuration Mode
LAN emulation (LANE) clients consult the LANE configuration server for information such as the location of the LANE server. The configuration server looks up the configuration information in its name database.
A LANE database contains entries that bind an emulated LAN name to the ATM address of the LANE server, bind LANE client MAC addresses to an emulated LAN name, and bind LANE client ATM address templates to an emulated LAN name.
In LANE database configuration mode, you can use the client-atm-address name, default name, mac-address name, and name server-atm-address commands to create entries in the specified database.
Refer to the "LAN Emulation Commands" chapter of the Cisco IOS Switching Services Command Reference.
Line Configuration Mode
Line configuration commands modify the operation of an auxiliary, console, physical, or virtual terminal line. Line configuration commands always follow a line command, which defines a line number. These commands are generally used to connect to remote routers or access servers, change terminal parameter settings either on a line-by-line basis or for a range of line, and set up the auxiliary port modem configuration to support dial-on-demand routing (DDR). See the "Configuring Modem Support and Asynchronous Devices" chapter in the Dial Solutions Configuration Guide.
Map-Class Configuration Mode
Cisco IOS software allows you to specify parameters that control the traffic that the source router will send over a switched virtual circuit (SVC). See the "Configuring ATM on the AIP for Cisco 7000 and 7500 Series Routers" and "Configuring ATM on the NPM for Cisco 4500 and 4700 Routers" chapters in the Wide-Area Networking Configuration Guide.
Map-List Configuration Mode
Cisco IOS ATM and Frame Relay software supports static mapping schemes that identify the protocol addresses of remote hosts or routers. For a listing of which Cisco platforms support ATM and Frame Relay, see the "Platform Support" appendix in the Configuration Fundamentals Command Reference.
Map-list configuration commands configure a map list. They always follow a map-list global configuration command. See the "ATM Commands" chapter in the Wide-Area Networking Command Reference.
Response Time Reporter Configuration Mode
Use the response time reporter configuration mode to configure a probe to measure response times and availability. Refer to the "Monitoring the Router and Network" chapter in the Configuration Fundamentals Configuration Guide.
Route-Map Configuration Mode
Use the route-map configuration mode to configure routing table and source and destination information. See the "Configuring IP Routing Protocol-Independent Features" chapter in the Network Protocols Configuration Guide, Part 1.
Router Configuration Mode
Router configuration commands configure an IP routing protocol and always follow a router command. See the relevant chapter on your IP routing protocol in the Network Protocols Configuration Guide, Part 1.
TN3270 Server Command Modes
The TN3270 server provides a set of command modes. The TN3270 server can be configured only on Port 2, the internal LAN port, of a Channel Interface Processor (CIP) card.
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The following are the TN3270 server command modes:
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Summary of Configuration Command Modes
lists the command modes, how to access and exit each mode, the prompt while in each mode, and an example of how to get to the mode. The exit method is only listed if the exit command does not return you to global configuration mode or you must use a different command to exit the mode. The prompts listed assume that the default device name is "Router."
Using the No and Default Forms of Commands
Almost every configuration command also has a no form. In general, use the no form to disable a feature or function. Use the command without the keyword no to reenable a disabled feature or to enable a feature that is disabled by default. For example, IP routing is enabled by default. To disable IP routing, specify the no ip routing command and specify ip routing to reenable it. The Cisco IOS software command references provides the complete syntax for the configuration commands and describes what the no form of a command does.
Configuration commands can also have a default form. The default form of a command returns the command setting to its default. Most command are disabled by default, so the default form is the same as the no form. However, some commands are enabled by default and have variables set to certain default values. In these cases, the default command enables the command and sets variables to their default values. The Cisco IOS software command references describe what the default form of a command does if the command is not the same as the no form.
Get Context-Sensitive Help
Entering a question mark (?) at the system prompt displays a list of commands available for each command mode. You can also get a list of any command's associated keywords and arguments with the context-sensitive help feature.
To get help specific to a command mode, a command, a keyword, or arguments, perform one of the following tasks:
When using context-sensitive help, the space (or lack of a space) before the question mark (?) is significant. To obtain a list of commands that begin with a particular character sequence, type in those characters followed immediately by the question mark (?). Do not include a space. This form of help is called word help, because it completes a word for you.
To list keywords or arguments, enter a question mark (?) in place of a keyword or argument. Include a space before the ?. This form of help is called command syntax help, because it reminds you which keywords or arguments are applicable based on the command, keywords, and arguments you already have entered.
You can abbreviate commands and keywords to the number of characters that allow a unique abbreviation. For example, you can abbreviate the show command to sh.
Enter the help command (which is available in any command mode) for a brief description of the help system:
Router# helpHelp may be requested at any point in a command by enteringa question mark '?'. If nothing matches, the help list willbe empty and you must back up until entering a '?' shows theavailable options.Two styles of help are provided:1. Full help is available when you are ready to enter acommand argument (e.g. 'show ?') and describes each possibleargument.2. Partial help is provided when an abbreviated argument is enteredand you want to know what arguments match the input(e.g. 'show pr?'.)As described in the help command output, you can enter a partial command name and a question mark (?) to obtain a list of commands beginning with a particular character set. (See the section "Complete a Partial Command Name" later in this chapter for more details.)
Example of Context Sensitive Help
The following example illustrates how the context-sensitive help feature enables you to create an access list from configuration mode.
Enter the letters co at the system prompt followed by a question mark (?). Do not leave a space between the last letter and the question mark (?). The system provides the commands that begin with co.
Router# co?configure connect copyEnter the configure command followed by a space and a question mark (?) to list the command's keywords and a brief explanation:
Router# configure ?memory Configure from NV memorynetwork Configure from a TFTP network hostterminal Configure from the terminal<cr>Enter the terminal keyword to enter configuration mode from the terminal:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)#Enter the access-list command followed by a space and a question mark (?) to list the command's keywords:
Router(config)# access-list ?<1-99> IP standard access list<100-199> IP extended access list<1000-1099> IPX SAP access list<1100-1199> Extended 48-bit MAC address access list<200-299> Protocol type-code access list<300-399> DECnet access list<400-499> XNS standard access list<500-599> XNS extended access list<600-699> Appletalk access list<700-799> 48-bit MAC address access list<800-899> IPX standard access list<900-999> IPX extended access listThe two numbers within the angle brackets represent an inclusive range. Enter the access list number 99 and then enter another question mark (?) to see the arguments that apply to the keyword and brief explanations:
Router(config)# access-list 99 ?deny Specify packets to rejectpermit Specify packets to forwardEnter the deny argument followed by a question mark (?) to list additional options:
Router(config)# access-list 99 deny ?A.B.C.D Address to matchGenerally, uppercase letters represent variables, though this is not always the case. Enter the IP address followed by a question mark (?) to list additional options:
Router(config)# access-list 99 deny 131.108.134.0 ?A.B.C.D Mask of bits to ignore<cr>The <cr> symbol appears in the list to indicate that one of your options is to press Return to execute the command.
The other option is to add a wildcard mask. Enter the wildcard mask followed by a question mark (?) to list further options.
Router(config)# access-list 99 deny 131.108.134.0 0.0.0.255 ?<cr>Router(config)# access-list 99 deny 131.108.134.0 0.0.0.255The <cr> symbol by itself indicates there are no more keywords or arguments. Press Return to execute the command. The system adds an entry to access list 99 that denies access to all hosts on subnet 131.108.134.0.
Display Help for All User-Level Commands
To configure a line to display help for the full set of user-level commands during all sessions, perform the following tasks in line configuration mode:
Configure a line or lines to receive help for the full set of user-level commands when a user presses ?.
full-help
To configure the current session to display help for the full set of user-level commands, perform the following task in user exec mode:
Configure this session to provide help for the full set of user-level commands.
terminal full-help
The full-help and terminal full-help commands enable (or disable) a display of all help messages available from the terminal. They are used with the show command.
The following example is output for show ? with terminal full-help disabled and then enabled:
Router> show ?bootflash Boot Flash informationcalendar Display the hardware calendarclock Display the system clockcontext Show context informationdialer Dialer parameters and statisticshistory Display the session command historyhosts IP domain-name, lookup style, nameservers, and host tableisdn ISDN informationkerberos Show Kerberos Valuesmodemcap Show Modem Capabilities databaseppp PPP parameters and statisticsrmon rmon statisticssessions Information about Telnet connectionssnmp snmp statisticsterminal Display terminal configuration parametersusers Display information about terminal linesversion System hardware and software statusRouter> terminal full-helpRouter> show ?access-expression List access expressionaccess-lists List access listsaliases Display alias commandsapollo Apollo network informationappletalk AppleTalk informationarp ARP tableasync Information on terminal lines used as router interfacesbootflash Boot Flash informationbridge Bridge Forwarding/Filtering Database [verbose]bsc BSC interface informationbstun BSTUN interface informationbuffers Buffer pool statisticscalendar Display the hardware calendarcdp CDP informationclns CLNS network informationclock Display the system clockcls DLC user informationcmns Connection-Mode networking services (CMNS) information...x25 X.25 informationxns XNS informationxremote XRemote statisticsCheck Command Syntax
The user interface provides error isolation in the form of an error indicator, a caret symbol (^). The ^ symbol appears at the point in the command string where you have entered an incorrect command, keyword, or argument.
In the following example, suppose you want to set the clock. Use context-sensitive help to check the syntax for setting the clock.
Router# clock ?set Set the time and dateRouter# clockThe help output shows that the set keyword is required. Check the syntax for entering the time:
Router# clock set ?hh:mm:ss Current timeRouter# clock setEnter the current time:
Router# clock set 13:32:00% Incomplete command.The system indicates that you need to provide additional arguments to complete the command. Press Ctrl-P (see the next section, "Use the Command History Features") to automatically repeat the previous command entry. Then add a space and question mark (?) to reveal the additional arguments:
Router# clock set 13:32:00 ?<1-31> Day of the monthJanuary Month of the yearFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecemberNow you can complete the command entry:
Router# clock set 13:32:00 23 February 97^% Invalid input detected at '^' marker.The caret symbol (^) and help response indicate an error at 97. To list the correct syntax, enter the command up to the point where the error occurred and then enter a question mark (?):
Router# clock set 13:32:00 23 February ?<1993-2035> YearRouter# clock set 13:32:00 23 FebruaryEnter the year using the correct syntax and press Return to execute the command.
Router# clock set 13:32:00 23 February 1997Use the Command History Features
With the current Cisco IOS release, the user interface provides a history or record of commands that you have entered. This feature is particularly useful for recalling long or complex commands or entries, including access lists. With the command history feature, you can complete the tasks in the following sections:
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Set the Command History Buffer Size
By default, the system records 10 command lines in its history buffer. To set the number of command lines that the system will record during the current terminal session, complete the following task in EXEC mode:
Enable the command history feature for the current terminal session.
terminal history [size number-of-lines]
The terminal no history size command resets the number of lines saved in the history buffer to the default of 10 lines.
To configu
