# Using Help

The system CLI provides a variety of useful context-sensitive help features. An important thing to remember about using the help features is that the use of a space or the lack of a space before the ? gives different results. Table 6 describes the help system.

Table 6: Help Commands

Command | Description
--- | ---
? | Lists all keywords applicable to the current command mode
help | Displays a brief description of the help system (available in all command modes)
partial-keyword? | Lists the keywords that begin with a certain character string
partial-keyword<Tab> | Completes the partial keyword you entered, if you have provided an unambiguous abbreviation
command<Space>? | Lists the set of all valid next available choices

Commands listed in the left column of Table 6 are further described with examples in the following sections.

## ? (Question Mark Key)

You can use the question mark (?) key whenever you need additional information. When you enter ?, all available choices are displayed. The CLI then redisplays the command you typed. The following examples show different ways you can use the ? key.

When you use ? on a line by itself or when it is preceded by one or more spaces, a list of all next available choices is displayed.

Example 1

    host1(config)#?
      aaa                      Configure authentication, authorization, and
                               accounting characteristics
      access-list              Configure an access list entry
      arp                      Configure a static ARP entry
      bandwidth                Configure slot-group bandwidth control
      banner                   Define a banner line
      baseline                 Configure baseline operations
      boot                     Configure boot time behavior
      bulkstats                Configure bulkstats parameters
      classifier-list          Configure a classifier list entry
      clns                     Configure CLNS characteristics
      clock                    Set the system's clock
      confirmations            Configure confirmation mode
      controller               Configure controller parameters
      crypto                   Configure cryptographic parameters
      default                  Set a command to its default(s)
      disable-autosync         Disable automatic synchronization of redundant
                               system controller file system
      disable-switch-on-error  Disable automatic switch to redundant system
                               controller upon software/hardware error
      do                       Run an exec mode command (alias command run)
      enable                   Configure security related options
      end                      Exit Global Configuration mode
      exception                Configure core dump
      exclude-subsystem        Exclude copying a subsystem from the release
      exit                     Exit from the current command mode
      ftp-server               Configure FTP Server characteristics
      help                     Describe the interactive help system
      host                     Add/modify an entry to the host table
      hostname                 Set the host (system) name
      interface                Enter Interface Configuration mode
      ip                       Configure IP characteristics
      l2tp                     Configure L2TP parameters
      license                  Configure licenses
      line                     Enter Line Configuration mode
      log                      Configure logging settings
      macro                    Run a CLI macro
      map-list                 Create an NBMA static map
      memory                   Configure and administer memory operations
      mpls                     Configure MPLS global parameters
      no                       Negate a command or set its default(s)
      ntp                      Configure the Network Time Protocol
      policy-list              Enter Policy Configuration mode
      pppoe                    Configure PPPoE
      profile                  Specify a profile
      radius                   Configure RADIUS server
      rate-limit-profile       Enter rate limit profile configuration mode
      redundancy               Perform a redundancy configuration
      route-map                Configure a route map
      router                   Configure a routing protocol
      rtr                      Configure rtr parameters
      run                      Run an exec mode command (alias command do)
      service                  Configure system-level services
      set                      Configure
      sleep                    Make the Command Interface pause for a specified
                               duration
      slot                     Configure and administer slot operation
      snmp-server              Configure SNMP parameters
      sscc                     The SSC Client telnet
      telnet                   telnet daemon configuration
      timing                   Configure network timing
      traffic-shape-profile    Enter traffic shape profile configuration mode
      virtual-router           Specify a virtual router

Example 2

    host1(config)#ip ?
    address-pool                Configure address pool for PPP Broadband RAS
                                clients
      as-path                   Configure a path filter for AS-Paths in BGP
      bgp-community             Format for BGP community
      community-list            Configure an entry in a community list
      debounce-time             Specify the minimum amount of time that an event
                                needs to be in same state before being reported
      dhcp-local                The DHCP Local Server protocol
      dhcp-server               DHCP Server for Proxy Client
      domain-lookup             Enable DNS lookup
      domain-name               Specify local Domain name
      dvmrp                     configure dvmrp paramaters
      dynamic-interface-prefix  Specify name prefix for dynamic Ip shared
                                interfaces
      explicit-path             Configure an explicit path
      extcommunity-list         The extended community list
      ftp                       Configure FTP characteristics
      http                      Configure http server
      local                     Local IP address assignment
      multicast-routing         Enable IP multicast forwarding
      name-server               Configure DNS server
      pim                       Configure PIM Protocol
      prefix-list               Configure a prefix list entry
      prefix-tree               Configure a prefix tree entry
      route                     Define a static IP route
      router-id                 Configure the router-id to be used
      rpf-route                 Define a static IP route for mcast RPF check
      source-route              Configure source-routing capabilities
      ssh                       Configure SSH characteristics
      ttl                       Configure the default value to be used by IP for
                                Time-To-Live
      tunnel                    Configure tunnel parameter
      vpn-id                    Configure the VPN ID associated with this router
      vrf                       Specify a VRF

    host1(config)#ip

Example 3

    host1(config)#ip community-list ?
    <1 - 99>  The community list

    host1(config)#ip community-list

When you want to see a list of commands that begin with a particular set of characters, type a question mark ( ? ) immediately after the last letter. Do not use a space between the partial keyword and the ? key. For example:

    host1#sh?
    show shutdown
    host1#sh

| Note: If you want to use the ? character as part of a string, such as a hostname or a regular expression, you must enter the following key sequence: Ctrl+v+?. Otherwise, the CLI considers the ? to be a request for assistance in completing the command.

## help Command

Use the help command when you want to see a brief description of the context-sensitive help system.

host1>help Use the help options as follows:
?, or command<Space>? - Lists the set of all valid next keywords or arguments partial-keyword? - Lists the keywords that begin with a certain character string partial-keyword<Tab> - Completes the partial keyword host1>

## Partial-keyword <Tab>

When you cannot recall a complete command name or keyword, type in the first few letters, press Tab, and the system completes your partial entry. You must type enough characters to provide a unique abbreviation. If you type a few letters, press Tab, and your terminal beeps, then you have not typed enough characters to be unambiguous.

host1(config)#int<Tab> host1(config)#interface