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




Lists all keywords applicable to the current command mode


Displays a brief description of the help system
(available in all command modes)


Lists the keywords that begin with a certain character string


Completes the partial keyword you entered, if you have provided an unambiguous abbreviation


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

  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
  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
  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 parameters
  dynamic-interface-prefix  Specify name prefix for dynamic Ip shared
  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
  tunnel                    Configure tunnel parameter
  vpn-id                    Configure the VPN ID associated with this router
  vrf                       Specify a VRF

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:

show shutdown

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 argumentspartial-keyword? - Lists the keywords that begin with a certain character stringpartial-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