Getting Help About Statements

In configuration mode, you can use the help command to display help based on a text string contained in a statement name. This command displays help for statements at the current hierarchy level and below.

user@host# help  string 

You can also display help based on a text string contained in a statement name using the help topic and help reference commands. The help topic command displays usage guidelines for the statement, whereas the help reference command displays summary information about the statement.

user@host# help topic ?

  access                                                       Network access control

  accounting-options                                        Accounting data collection

  applications                                                 Application protocols

  bgp                                                          Border Gateway Protocol

  chassis                                                      Platform

  class-of-service                                             Class of service (CoS)

  connections                                                  Circuit cross-connect (CCC)

  dvmrp                                                        Distance Vector Multicast Routing Protocol

  firewall                                                     Firewalls and filters

  forwarding-options                                           Packet sampling

  groups                                                       Configuration groups

  igmp                                                         Internet Group Management Protocol

  interfaces                                                   Interfaces

  isis                                                         Intermediate System-to-Intermediate System

  l2circuit                                                    Layer 2 virtual circuits

  layer2-vpns                                                  Layer 2 VPNs

  layer3-vpns                                                  Layer 3 VPNs

  ldp                                                          Label Distribution Protocol

  link-management                                              Link Management Protocol

  logical-routers                                              Logical routers

  mld                                                          Multicast Listener Discovery protocol

  mpls                                                         Multiprotocol Label Switching

  msdp                                                         Multicast Source Discovery Protocol

  ospf                                                         Open Shortest Path First protocol

  pgm                                                          Pragmatic Generalized Multicast

  pim                                                          Protocol-Independent Multicast and data MDT

  policy-options                                               Routing policy

  rip                                                          Routing Information Protocol

  ripng                                                        Routing Information Protocol Next Generation

  rmon                                                         Remote Monitoring

  router-advertisement                                          Neighbor discovery

  router-discovery                                             Internet Control Message Protocol router discovery

  routing-instances                                            Routing instances

  routing-options                                              Protocol-independent routing options

  rsvp                                                         Resource Reservation Protocol

  sap                                                          Session Advertisement Protocol

  security                                                     Internet Protocol security (IPSec)

  services                                                     Service sets for Adaptive Services PIC

  snmp                                                         Simple Network Management Protocol

  system                                                       System parameters

  vpls                                                         Virtual private LAN service

  vpns                                                         Virtual private networks

[edit]

user@help# help topic access ?

Possible completions:

  examples             

  l2tp                                                             Overview of Layer 2 Tunneling Protocol configuration

  point-to-point                                                   Overview of Point-to-Point Protocol configuration

  radius-disconnect-port                                              Port number for RADIUS disconnect server

  radius-server                                                    RADIUS server configuration

  traceoptions                                                     Trace options for access processes

  tunnel-profile                                                   Join multilink bundles based on endpoint discriminator

[edit]

user@host# help topic access point-to-point 

Configuring the Point-to-Point Protocol

   To configure the Point-to-Point Protocol (PPP), do the following:

     * Configuring the Challenge Handshake Authentication Protocol

     * Configuring the Authentication Order

user@host# help reference string

If you do not type an option for a statement that requires one, a message indicates the type of information expected. In this example, you need to type an area number to complete the command:

[edit]

user@host# set protocols ospf area<Enter>

syntax error, expecting <identifier>.

In this example, you need to type a value for the hello interval to complete the command:

[edit]

user@host# set protocols ospf area 45 interface so-0/0/0     

                  hello-interval<Enter>

syntax error, expecting <data>

If you have omitted a required statement at a particular hierarchy level, when you attempt to move from that hierarchy level or when you issue the show command in configuration mode, a message indicates which statement is missing. For example:

[edit protocols pim interface so-0/0/0]

user@host# top

Warning: missing mandatory statement: 'mode'

[edit]

user@host# show

protocols {

    pim {

        interface so-0/0/0 {

            priority 4;

            version 2;

            # Warning: missing mandatory statement(s): 'mode'

        }

    }

}