Cisco IOS Dial Services Commands

Syntax Description

radius	Use RADIUS for static route download.
tacacs+	Use TACACS+ for static route download.

Defaults

No configuration authorization is defined.

Command Modes

Global configuration

Command History

Release	Modification
12.0(3)T	This command was introduced.

Examples

The following example downloads static route information using a TACACS+ server:

aaa authorization configuration default tacacs+

Related Commands

Command	Description
aaa new-model	Enables the AAA access control model.
aaa route download	Enables the download static route feature and sets the amount of time between downloads.
clear ip route download	Clears static routes downloaded from a AAA server.
show ip route	Displays all static IP routes, or those installed using the AAA route download function.

Syntax Description

aaa-group-name

Character string used to name the group of AAA servers.

Defaults

No default behavior or values.

Command Modes

Interface

Customer profile subcommand

Command History

Release	Modification
12.0(6)T	This command was introduced.

Usage Guidelines

The AAA server group feature introduces a way to group existing server hosts. The feature enables you to select a subset of the configured server hosts and use them for a particular service.

A server group is a list of server hosts of a particular type. Currently supported server host types are RADIUS server hosts and TACACS+ server hosts. A server group is used with a global server host list. The server group lists the IP addresses of the selected server hosts.

Examples

The following example shows a AAA server group by the name of radius-3 being associated with a customer profile by the name of acme.

resource-pool profile customer acme
aaa group-configuration radius-3

Related Commands

Command	Description
aaa accounting	Enables AAA accounting of requested services for billing or security purposes.
aaa authentication login	Enables AAA accounting of requested services for billing or security purposes.
aaa authorization	Sets parameters that restrict network access to a user.
aaa new-model	Enables the AAA access control model.
radius-server host	Specifies a RADIUS server host.
tacacs-server host	Specifies a TACACS host.

Syntax Description

time	(Optional) Time between downloads, in minutes. The range is 1 to 1440 minutes.

Defaults

The default period between downloads (updates) is 720 minutes.

Command Modes

Global configuration

Command History

Release	Modification
12.0(3)T	This command was introduced.

Usage Guidelines

This command is used to download static route details from the authorization, authentication, and accounting (AAA) server if the name of the router is hostname. The name passed to the AAA server for static routes is hostname-1, hostname-2 .... hostname-n---the router downloads static routes until it fails an index and no more routes can be downloaded.

Examples

The following example sets the AAA route update period to 100 minutes:

aaa route download 100

Related Commands

Command	Description
aaa authorization configuration default	Downloads static route configuration information from the AAA server using TACACS+ or RADIUS.
clear ip route download	Clears static routes downloaded from a AAA server.
show ip route	Displays all static IP routes, or those installed using the AAA route download function.

Syntax Description

minutes

The number of minutes after which the user's session will be terminated.

Defaults

No timeout interval is automatically set.

Command Modes

Line configuration

Command History

Release	Modification
11.0	This command was introduced.

Usage Guidelines

Note You can set this command and an AppleTalk Remote Access Protocol (ARAP) timeout for the same line; however, this command supersedes any timeouts set in ARAP. Additionally, ARAP users will receive no notice of any impending termination if you use this command.

Examples

The following example sets an interval of 60 minutes on line 5:

line 5
 absolute-timeout 60

Related Commands

Command	Description
logout-warning	Warns users of an impending forced timeout.
session-timeout	Sets the interval for closing the connection when there is no input or output traffic.

Syntax Description

access-list-number	Specifies an integer between 1 and 199 that defines the access list.
in	Controls which nodes can make local-area transport (LAT) connections into the server.
out	Defines the access checks made on outgoing connections. (A user who types a node name at the system prompt to initiate a LAT connection is making an outgoing connection.)

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command defines access list numbers that will then be used with the lat access-list command to specify the access conditions.

The value supplied for the access-list-number argument is used for all protocols supported by the Cisco IOS software. If you are already using an IP access list, you must define local-area transport (LAT) and possibly X.25 access lists permitting connections to everything, to emulate the behavior of previous software versions.

When both IP and LAT connections are allowed from a terminal line and an IP access list is applied to that line with the access-class line configuration command, you must also create a LAT access list with the same number if you want to allow any LAT connections from that terminal. You can specify only one incoming and one outgoing access list number for each terminal line. When checking LAT access lists, if the specified list does not exist, the system denies all LAT connections.

Examples

The following example configures an incoming access class on virtual terminal line 4:

line vty 4
 access-class 4 in

Related Commands

Command	Description
lat access-list	Specifies access conditions to nodes on the LAT network.

Syntax Description

This command has no arguments or keywords.

Defaults

Callback requests are not accepted on lines configured for ARA.

Command Modes

Global configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

This command enables the router to accept callback requests from ARA clients. You first have to enable AppleTalk routing on the router and then enable automatic ARA startup on the line. You can use this command with either local username authentication or TACACS+ authentication.

Examples

The following example accepts a callback request from an ARA client:

arap callback

Related Commands

Command	Description
arap callback	Enables an ARA client to request a callback from an ARA client.
autoselect	Configures a line to start an ARA, PPP, or SLIP session.
	Forces the Cisco IOS software to wait before initiating a callback to a requesting client.
ppp bap call	Sets PPP BACP call parameters.
ppp callback (DDR)	Enables a dialer interface that is not a DTR interface to function either as a callback client that requests callback or as a callback server that accepts callback requests.
server (RLM)	Enables the Cisco IOS software to call back clients that request a callback from the EXEC level.
virtual-profile aaa	Enables virtual profiles by AAA configuration.

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Examples

The following example configures line 3 to be used only for ARA connections:

line 3 
 arap dedicated

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Examples

The following example enables ARA on a line:

line 3 
 arap enable

Related Commands

Command	Description
appletalk routing	Enables AppleTalk routing.
autoselect	Configures a line to start an ARA, PPP, or SLIP session.

Syntax Description

net-access-list-number

One of the list values configured using the AppleTalk access-list cable-range, access-list includes, access-list network, access-list other-access, and access-list within commands.

Defaults

Disabled. The Macintosh has access to all networks.

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

You can use the arap net-access-list command to apply access lists defined by the access-list cable-range, access-list includes, access-list network, access-list other-access, and access-list within commands.

You cannot use the arap net-access-list command to apply access lists defined by the access-list zone and access-list additional-zones commands.

Examples

In the following example, ARA is enabled on line 3 and the Macintosh will have access to the AppleTalk access list numbered 650:

line 3
 arap enable
 arap net-access-list 650

Related Commands

Command	Description
arap zonelist	Controls which zones the Apple Macintosh client sees.

Syntax Description

network-number	(Optional) AppleTalk network number. The network number must be unique on your AppleTalk network. This network is where all ARAP users appear when they dial in to the network.
zone-name	(Optional) AppleTalk zone name.

Defaults

A new network or zone is not created.

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This is a required command. ARAP does not run without it in Cisco IOS Release 10.2 and later.

Examples

The following example creates a new network/zone:

arap network 400 test zone

Syntax Description

if-needed

(Optional) Does not authenticate if the user already provided authentication. This allows users to log in as guests if they have already been authenticated through a username or password.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

A guest is a person who connects to the network without having to give a name or a password.

Caution You should not use the arap noguest command if you are using modified Common Command Language (CCL) scripts and the login tacacs command.

Examples

The following example prohibits guests from logging in to the router:

line 3
 arap enable
 arap noguest

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
11.1	This command was introduced.

Usage Guidelines

This command only works for AppleTalk Remote Access Protocol (ARAP) 2.0 connections.

Examples

The following example forces users to enter their passwords manually at the time they log in, rather than use a saved password:

arap require-manual-password

Related Commands

Command	Description
enable password	Sets a local password to control access to various privilege levels.
login (line)	Enables password checking at login and defines the method (local or TACACS+).
peer default ip address	Specifies an IP address, an address from a specific IP address pool, or an address from the DHCP mechanism to be returned to a remote peer connecting to this interface.

Syntax Description

minutes

(Optional) Maximum length of time (in minutes) for a session.

Defaults

Unlimited session length

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

After the specified length of time, the session will be terminated.

Examples

The following example specifies a maximum length of 20 minutes for ARA sessions:

line 3
 arap enable
 arap timelimit 20 

Related Commands

Command	Description
arap warningtime	Sets when a disconnect warning message is displayed.

Syntax Description

minutes

(Optional) Amount of time, in minutes, before the configured session time limit. At the configured amount of time before a session is to be disconnected, the router sends a message to the Macintosh client, which causes a warning message to appear on the user's screen.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command can only be used if a session time limit has been configured on the line.

Examples

The following example shows a line configured for 20-minute AppleTalk Remote Access (ARA) sessions, with a warning 17 minutes after the session is started:

line 3
 arap enable
 arap dedicated
 arap timelimit 20
 arap warningtime 3 

Related Commands

Command	Description
arap timelimit	Sets the maximum length of an ARA session for a line.

Syntax Description

zone-access-list-number

One of the list values configured using the AppleTalk access-list zone or access-list additional-zones commands.

Defaults

Disabled. The Macintosh will see all defined zones.

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

You can use the arap zonelist command to apply access lists defined by the access-list zone and access-list additional-zones commands.

You cannot use the arap zonelist command to apply access lists defined by the access-list network command.

Hiding a zone from users is not the same as preventing them from sending and receiving packets from the networks that make up that zone. For true security, an arap net-access-list command must be issued to prevent traffic to and from those networks.

Examples

The following example enables AppleTalk Remote Access (ARA) on line 3; the Macintosh will see only zones permitted by access list 650.

line 3
 arap enable
 arap zonelist 650

Related Commands

Command	Description
arap net-access-list	Controls Apple Macintosh access to networks.

See the description of the peer default ip address command in this book for more information.

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Use the async default routing command to define the default behavior for router-to-router communication over connections to the AUX port configured as an asynchronous interface. This command is commonly used to enable two routers to communicate over an async dial backup link.

To require a remote user to manually configure routing over connections to the AUX port configured as an asynchronous interface, use the async dynamic routing command.

Examples

The following example enables routing over asynchronous interface 0:

interface async 0
async default routing

Related Commands

Command	Description
async dynamic routing	Enables manually configured routing on an asynchronous interface.

Syntax Description

This command has no arguments or keywords.

Defaults

Dynamic addressing is disabled.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

You can control whether addressing is dynamic (the user specifies the address at the EXEC level when making the connection), or whether default addressing is used (the address is forced by the system). If you specify dynamic addressing, the router must be in interactive mode and the user will enter the address at the EXEC level.

It is common to configure an asynchronous interface to have a default address and to allow dynamic addressing. With this configuration, the choice between the default address or a dynamic addressing is made by users when they enter the slip or ppp EXEC command. If the user enters an address, it is used, and if the user enters the default keyword, the default address is used.

Examples

The following example shows dynamic addressing assigned to async interface six.

interface ethernet 0
 ip address 10.0.0.1 255.0.0.0
interface async 6
 async dynamic address

Related Commands

Command	Description
peer default ip address	Specifies an IP address, an address from a specific IP address pool, or an address from the DHCP mechanism to be returned to a remote peer connecting to this interface.

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

The async dynamic routing command is commonly used to manually bring up PPP from an EXEC session.

Examples

The following example shows how to enable manually configured routing on asynchronous interface 1. The ip tcp header-compression passive command enables Van Jacobson TCP header compression and prevents transmission of compressed packets until a compressed packet arrives from the asynchronous link.

interface async 1
async dynamic routing
async dynamic address
async default ip address 1.1.1.2
ip tcp header-compression passive

A remote user who establishes a PPP or SLIP connection to this asynchronous interface can enable routing by using the /routing switch or the ppp/routing command.

However, if you want to establish routing by default on connections to an asynchronous interface, use the async default routing command when you configure the interface.

Related Commands

Command	Description
async default routing	Enables the router to pass routing updates to other routers over the AUX port configured as an asynchronous interface.
async dynamic address	Specifies dynamic asynchronous addressing versus default addressing.
ip tcp header-compression	Enables TCP header compression.

Syntax Description

This command has no arguments or keywords.

Defaults

Asynchronous mode is disabled.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

With dedicated asynchronous network mode, the interface will use either SLIP or PPP encapsulation, depending on which encapsulation method is configured for the interface. An EXEC prompt does not appear, and the router is not available for normal interactive use.

If you configure a line for dedicated mode, you will not be able to use the async dynamic address command, because there is no user prompt.

Examples

The following example assigns an IP address to an asynchronous line and places the line into network mode. Setting the stop bits to 1 enhances performance.

interface async 4
 async default ip address 172.31.7.51
 async mode dedicated
 encapsulation slip
 
line 20 
 location Joe's computer
 stopbits 1
 speed 115200

Related Commands

Command	Description
async mode interactive	Returns a line that has been placed into dedicated asynchronous network mode to interactive mode, thereby enabling the slip and ppp EXEC commands.

Syntax Description

This command has no arguments or keywords.

Defaults

Asynchronous mode is disabled.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

Interactive mode enables the slip and ppp EXEC commands. In dedicated mode, there is no user EXEC level. The user does not enter any commands, and a connection is automatically established when the user logs in, according to the configuration.

Examples

The following example places async interface 6 into interactive asynchronous mode:

interface async 6
 async default ip address 172.31.7.51
 async mode interactive
 ip unnumbered ethernet 0

Related Commands

Command	Description
async mode dedicated	Places a line into dedicated asynchronous mode using SLIP or PPP encapsulation.

Syntax Description

command

Any appropriate EXEC command, including the host name and any switches that occur with the EXEC command.

Defaults

No commands are configured to automatically execute.

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command enables you to automatically execute an EXEC command when a user connects to a line.

Examples

The following example forces an automatic connection to a host named host21 (which could be an IP address):

line vty 4
 autocommand connect host21

Syntax Description

lapb-ta	Automatically detects Link Access Procedure, Balanced (LAPB) for an ISDN terminal adapter.
ppp	Automatically detects PPP encapsulation on the interface.
v120	Automatically detects V.120 encapsulation on B channels.

Defaults

No default behavior or values.

Command Modes

Interface configuration

Command History

Release	Modification
11.2	This command was introduced.
12.0(4)T	The lapb-ta keyword was added.

Usage Guidelines

At least one encapsulation type is required in the command, but you can specify additional encapsulation types.

Autodetection of LAPB traffic on an ISDN terminal adapter is now possible, by adding the keyword lapb-ta to the command line. This allows recognition of incoming LAPB-TA calls.

Automatic detection is attempted for the first 10 seconds after the link is established or the first five packets exchanged over the link, whichever is first.

Examples

The following example configures BRI 0 to call and receive calls from two sites, use Point-to-Point Protocol (PPP) encapsulation on outgoing calls, and use Challenge Handshake Authentication Protocol (CHAP) authentication on incoming calls. This example also enables BRI 0 to configure itself dynamically to answer calls that use V.120 but that do not signal V.120.

interface bri 0
 encapsulation ppp
 autodetect encapsulation v120
 no keepalive
 dialer map ip 131.108.36.10 name EB1 234
 dialer map ip 131.108 36.9 name EB2 456
 dialer-group 1
 isdn spid1 0146334600
 isdn spid2 0146334610
 isdn T200 1000
 ppp authentication chap
 

The following example enables the LAPB-TA and V.120 protocols for autodetection on interface serial0:23 after you have configured the virtual terminals to handle asynchronous traffic:

vty-async
interface serial0:23
 autodetect encapsulation lapb-ta v120

Related Commands

Command	Description
encapsulation	Sets the encapsulation method used by the interface.

Syntax Description

This command has no arguments or keywords.

Defaults

Disabled

Command Modes

Line configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command is useful for UNIX UNIX-to-UNIX Copy Program (UUCP) applications that automatically disconnect lines because UUCP scripts cannot issue the exit command to hang up the telephone.

Examples

The following example enables automatic line disconnect on lines 5 through 10:

line 5 10
 autohangup

Syntax Description

arap	Configures the Cisco IOS software to allow an ARA session to start up automatically.
ppp	Configures the Cisco IOS software to allow a PPP session to start up automatically.
slip	Configures the Cisco IOS software to allow a SLIP session to start up automatically.
during-login	The username and/or password prompt is displayed without pressing the Return key. After the user logs in, the autoselect function begins.

Defaults

ARA session

Command Modes

Line configuration

Command History

Release	Modification
10.3	This command was introduced.
11.0	The following keywords were added: during-login no autoselect

Usage Guidelines

This command eliminates the need for users to enter an EXEC command to start an ARA, PPP, or SLIP session.

Note SLIP does not support authentication. For PPP and ARAP, you must enable authentication.

The autoselect command configures the Cisco IOS software to identify the type of connection being requested. For example, when a user on a Macintosh running ARA selects the Connect button, the Cisco IOS software automatically starts an ARAP session. If, on the other hand, the user is running SLIP or PPP and uses the autoselect ppp or autoselect slip command, the Cisco IOS software automatically starts a PPP or SLIP session, respectively. This command is used on lines making different types of connections.

A line that does not have autoselect configured views an attempt to open a connection as noise. The router does not respond and the user client times out.

Note After the modem connection is established, a Return is required to evoke a response, such as to get the username prompt. You might need to update your scripts to include this requirement. Additionally, the activation character should be set to the default and the exec-character-bits set to 7. If you change these defaults, the application cannot recognize the activation request.

Examples

The following example enables ARA on a line:

line 3
 arap enable
 autoselect arap
 

The following example enables PPP on a line:

line 7
 autoselect ppp
 

line 3
 arap enable
 autoselect arap
 autoselect during-login
 arap noguest if-needed

Related Commands

Command	Description
arap warningtime	Sets when a disconnect warning message is displayed.
ppp bap call	Sets PPP BACP call parameters.

Syntax Description

ip ip-address	IP address of the HGW/LNS at the other end of the tunnel. This is the IP endpoint at the end of the tunnel, which is an HGW/LNS router.
limit number	(Optional) Limits sessions per backup. The limit can range from 0 to 32767. The default is no limit set.
priority number	(Optional) Priority level. Loadsharing is priority 1. Backup priority is between 2 and 32,767. The highest priority is 2, which is the first home gateway router to receive backup traffic. The lowest priority is 32,767. The priority group is used to support multiple levels of loadsharing and backup. The default is the lowest priority.

Defaults

No default behavior or values. This function is used only if it is configured.

Command Modes

VPDN group configuration

Command History

Release	Modification
12.0(4)XI	This command was introduced and applies to Cisco AS5200 and Cisco AS5300 access servers only.

Usage Guidelines

Use the backup VPDN group configuration command to configure an IP backup endpoint address.

Examples

The following examples show that the backup command is not available in the command line interface until you enter the request dialin command:

Router(config-vpdn)# vpdn-group customer1-vpdngroup
Router(config-vpdn)# ?
VPDN group configuration commands:
  accept   Accept a tunnel open request
  default  Set a command to its defaults
  exit     Exit from VPDN group configuration mode
  no       Negate a command or set its defaults
  request  Request to open a tunnel
 
Router(config-vpdn)# request dialin l2tp ip 10.2.2.2 domain customerx
?
VPDN group configuration commands:
  backup            Add backup address
  default           Set a command to its defaults
  dnis              Accept a DNIS tunnel
  domain            Accept a domain tunnel
  exit              Exit from VPDN group configuration mode
  force-local-chap  Force a CHAP challenge to be instigated locally
  l2tp              L2TP specific commands
  lcp               LCP specific commands
  loadsharing       Add loadsharing address
  local             local information, like name
  multilink         Configure limits for Multilink
  no                Negate a command or set its defaults
  request           Request to open a tunnel
 

The following example shows an IP backup endpoint address of 10.1.1.1 configured with a backup session limit of 5:

Router(config-vpdn)# backup ip 10.1.1.1 limit 5

Related Commands

Command	Description
request dialin	Configures a VPDN group to request L2F or L2TP tunnels to a home gateway and creates a request-dialin VPDN subgroup.

Syntax Description

enable-delay	Number of seconds that elapse after the primary line goes down before the Cisco IOS software activates the secondary line.
disable-delay	Number of seconds that elapse after the primary line comes up before the Cisco IOS software deactivates the secondary line.
never	Prevents the secondary line from being activated or deactivated.

Defaults

0 seconds

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

For environments in which spurious signal disruptions appear as intermittent lost carrier signals, we recommend that you enable some delay before activating and deactivating a secondary line.

Examples

The following example sets a 10-second delay on deactivating the secondary line (serial interface 0); however, the line is activated immediately:

interface serial 0
 backup delay 0 10

Cisco 7200 series and Cisco 7500 series routers

backup interface slot/port-adapter/port

no backup interface slot/port-adapter/port

Syntax Description

type number	Interface type and port number to use as the backup interface.
slot/port-adapter/port	Backplane slot number and port number on the interface. See your hardware installation manual for the specific slot and port numbers.

Defaults

Disabled

Command Modes

Command History

Release	Modification
11.0	This command was introduced.

Usage Guidelines

The interface you define with this command can back up only one other interface.

Note Routers support only serial and ISDN backup interfaces. Access servers support both asynchronous and serial backup interfaces.

Examples

The following example sets serial 1 as the backup line to serial 0:

interface serial 0
 backup interface serial 1
 

The following example on the Cisco 7200 sets serial 2 as the backup line to serial 1:

interface serial 1/1
 backup interface serial 2/2

Syntax Description

number

Dialer interface number to use as the backup interface.

Defaults

Disabled

Command Modes

Command History

Release	Modification
11.2	This command was introduced.

Usage Guidelines

Multiple dialer interfaces can use the same dialer pool, which might have a single ISDN interface as a member. Thus, that ISDN interface can back up different serial interfaces and can make calls to different sites.

Examples

The following example shows the configuration of a site that backs up two leased lines using one BRI. Two dialer interfaces are defined. Each serial (leased line) interface is configured to use one of the dialer interfaces as a backup. Both of the dialer interfaces use dialer pool 1, which has BRI 0 as a member. Thus, BRI 0 can back up two different serial interfaces and can make calls to two different sites.

interface dialer0
 ip unnumbered loopback0
 encapsulation ppp
 dialer remote-name Remote0
 dialer pool 1
 dialer string 5551212
 dialer-group 1
 
interface dialer1
 ip unnumbered loopback0
 encapsulation ppp
 dialer remote-name Remote1
 dialer pool 1
 dialer string 5551234
 dialer-group 1
 
interface bri 0
 encapsulation PPP
 dialer pool-member 1
 ppp authentication chap
 
interface serial 0
 ip unnumbered loopback0
 backup interface dialer 0
 backup delay 5 10
 
interface serial 1
 ip unnumbered loopback0
 backup interface dialer1
 backup delay 5 10

Syntax Description

enable-threshold	Percentage of the primary line's available bandwidth that the traffic load must exceed to enable dial backup.
disable-load	Percentage of the primary line's available bandwidth that the traffic load must be less than to disable dial backup.
never	Sets the secondary line never to be activated due to traffic load.

Defaults

No threshold is predefined.

Command Modes

Interface configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

When the transmitted or received load on the primary line is greater than the value assigned to the enable-threshold argument, the secondary line is enabled.

The secondary line is disabled when one of the following conditions occurs:

• The transmitted load on the primary line plus the transmitted load on the secondary line is less than the value entered for the disable-load argument.

• The received load on the primary line plus the received load on the secondary line is less than the value entered for the disable-load argument.

If the never keyword is used instead of an enable-threshold value, the secondary line is never activated because of traffic load. If the never keyword is used instead of a disable-load argument, the secondary line is never activated because of traffic load.

Examples

The following example sets the traffic load threshold to 60 percent of the primary line serial 0. When that load is exceeded, the secondary line is activated, and will not be deactivated until the combined load is less than 5 percent of the primary bandwidth.

interface serial 0
 backup load 60 5
 backup interface serial 1

Syntax Description

hostname	Name of the host that cannot be reached.
d	Delimiting character of your choice---a pound sign (#) for example. You cannot use the delimiting character in the message.
message	Message text.

Defaults

No message is displayed.

Command Modes

Global configuration

Command History

Release	Modification
10.0	This command was introduced.

Usage Guidelines

This command applies only to Telnet connections.

Defining a "host failed" message for a host prevents all Cisco IOS software-initiated user messages, including the initial message that indicates the connection is "Trying..." The busy-message command can be used in the autocommand command to suppress these messages.

Examples

The following example sets a message that will be displayed on the terminal whenever an attempt to connect to the host named dross fails. The pound sign (#) is used as a delimiting character.

busy-message dross #
Cannot connect to host. Contact the computer center.
#