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Cisco IOS Dial Services Command Reference, Release 12.1
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About the Cisco IOS Software Documentation
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Commands: A through B
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Commands: C
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Commands: D
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Commands: E through IP
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Commands IS through LAT
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Commands: LC through MOD
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Commands: MU through PPP
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Commands: PRI through SGBP
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Commands: SHOW A through E
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Commands: SHOW I through L
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Commands: SHOW M
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Commands: SHOW N through X
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Commands: SL through TN
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Commands: TR through VIR
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Commands: VPDN through X
- Appendixes
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Index
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Table Of Contents
ip route (large-scale dial-out)
encapsulation cpp
To enable encapsulation for communication with routers or bridges using the Combinet Proprietary Protocol (CPP), use the encapsulation cpp command in interface configuration mode. Use the no form of this command to disable CPP encapsulation.
encapsulation cpp
no encapsulation cpp
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to communicate over an ISDN interface with Cisco 700 and 800 series (formerly Combinet) routers that do not support PPP but do support CPP.
Currently, most Cisco routers do support PPP. Cisco routers can communicate over ISDN with these devices by using PPP encapsulation, which supports both routing and fast switching.
The Cisco 700 and 800 series routers support only IP, IPX, and bridging. For AppleTalk, these Cisco routers automatically perform half-bridging.
This command is supported on ISDN BRIs and Primary Rate Interfaces (PRIs) only.
Examples
The following example configures BRI 0 to communicate with a router or bridge that does not support PPP:
interface bri 0encapsulation cppcpp callback acceptcpp authenticationThe following example configures PRI interface serial 1/1:23 to communicate with a router or bridge that does not support PPP:
controller t1 1/1framing esflinecode b8zspri-group timeslots 1-23isdn switchtype primary-4ess!interface Serial1/1:23encapsulation cppcpp callback accept cpp authenticationRelated Commands
firmware location
To download firmware into the modems, use the firmware location command in Service Processing Element (SPE) configuration mode. The no form of the command reverts the router back to the system embedded image default.
firmware location {system | flash}: filename
no firmware location {system | flash}: filename
Syntax Description
Defaults
None
Command Modes
SPE configuration
Command History
12.0(4)XI1
This command was introduced.
12.0(6)T
This command was migrated to Release 12.0(6)T.
Usage Guidelines
Use the firmware location SPE configuration command to download firmware into your modems. The no form of the command reverts the router back to the system embedded default. When the access server is booted, the firmware location command displays the location for the firmware that is embedded in the Cisco IOS image. If the firmware location command was given to download a firmware image from flash and then the no version of the exact command is subsequently given, then the firmware location command will download the embedded firmware in Cisco IOS Software.
The firmware location command was first supported in Cisco IOS Release 12.0(4)XI1 along with the Resource Pool Management feature (although it can be used independently). For earlier images, use the copy command. For the Cisco IOS Release 12.0(4)XI1 images, the copy {flash | system | tftp} modem command will be disabled for MICA technologies modems and newer versions of Microcom modems (that is, 56 kbps). Old V.34 Microcom modems still use the copy command for downloading in Cisco IOS Release 12.0(4)XI1 images.
Note
This command should be used when traffic is low because the firmware location download will not begin until the modems have no active calls. Otherwise, use the firmware upgrade command to customize the scheduling of modem downloads for your needs.
Note
Examples
The following examples show downloads of firmware that was not bundled with the Cisco IOS image:
spe 1/2 1/4firmware location flash:portware.2620.iosspe 2/2 2/8firmware location flash:mcom-fw-dsp.5.1.9_47.22.binspe 2/12 2/23firmware location feature_card_flashThe following examples show downloads of firmware that was bundled with the Cisco IOS image:
spe 2/9 2/9firmware location system:/ucode/microcom_firmwarespe 1/5 1/7firmware location system:/ucode/mica_port_firmwareRelated Commands
firmware upgrade
To modify the way in which the Service Processing Element (SPE) will be downloaded, use the firmware upgrade command in SPE configuration mode. The no form of the command reverts the SPE back to the default SPE firmware upgrade option, busyout.
firmware upgrade {busyout | recovery | reboot}
no firmware upgrade
Syntax Description
busyout
Starts firmware upgrade immediately. (Default)
recovery
Delays firmware upgrade until recovery maintenance time.
reboot
Delays firmware upgrade until reboot.
Defaults
Busyout
Command Modes
SPE configuration
Command History
Usage Guidelines
This command is for SPEs that contain more than 1 modem.
The SPE firmware location command is designed to integrate all continuous SPE ranges containing the same firmware location. However, the firmware upgrade command will not affect the SPE ranges. As such, all SPEs within the SPE range must have the same firmware upgrade mode or the router will default the upgrade mode to busyout. As such, if you want to upgrade a single SPE within an existing SPE range with a different upgrade mode than is currently configured, you must first change the upgrade mode for the entire SPE range and then change the firmware location for the specific SPE being upgraded.
Furthermore, each time you merge SPE ranges due to configuration changes, verify that the configuration of the SPE firmware upgrade remains effective to what is desired.
Examples
If the busyout upgrade command is specified, or if no upgrade mode is specified, the SPE modems are set into a "pending download" state when you use the firmware location command on the specified SPE. The "pending download" state prevents any modem in that state to be allocated for new calls until the state is cleared. Modems with active calls remain active for their call durations, but enter the "pending download" state when they terminate. This "pending download" state can only be cleared when the SPE is finally downloaded. When all modems within the SPE are in the "pending download" and no active calls remain on the SPE, the SPE is reloaded. The busyout option is the fastest way to upgrade modems on an active router but can severely impact the capacity of the router during the upgrade. This is the default option for the firmware upgrade process:
firmware upgrade busyoutIf reboot upgrade is specified, the SPE modems are not reloaded to the new firmware location until the router is rebooted. The reboot upgrade option is useful for routers which need to have their SPE upgraded and are also going to be rebooted for maintenance. The new firmware can be configured, but will not take affect until the reboot takes place:
firmware upgrade rebootIf recovery upgrade is specified, the SPE modem are reloaded based on the modem recovery algorithm. The SPE modems are all set into a "pending upgrade" state when you use the firmware location command on this SPE. The "pending upgrade" state continues to allow modems to be allocated to modems for as long as there are active calls on the SPE. Only when no active calls exist on the SPE will the firmware download take place. Furthermore, at the configured "modem recovery maintenance time" (3:00 a.m.), the modem recovery maintenance process will, in a controller fashion, attempt to reload the modems by busying out the modems for a window duration of time to make the download take place. Consult the modem recovery documentation for further details. The recovery upgrade option is the least impacting way to upgrade modems on an active router. Capacity is kept at a maximum. However, this option may take a few days for all modems to be reloaded to the new firmware location:
firmware upgrade recoveryRelated Commands
flowcontrol
To set the method of data flow control between the terminal or other serial device and the router, use the flowcontrol command in line configuration mode. Use the no form of this command to disable flow control.
flowcontrol {none | software [lock] [in | out] | hardware [in | out]}
no flowcontrol {none | software [lock] [in | out] | hardware [in | out]}
Syntax Description
Defaults
No flow control
Command Modes
Line configuration
Command History
Usage Guidelines
When software flow control is set, the default stop and start characters are Ctrl-S and Ctrl-Q (XOFF and XON). You can change them with the stop-character and start-character commands.
If a remote Telnet device requires software flow control, the remote system should not be able to turn it off. Using the lock option makes it possible to refuse "dangerous" Telnet negotiations if they are inappropriate.
Examples
The following example sets hardware flow control on line 7:
line 7flowcontrol hardwareRelated Commands
flush-at-activation
To discard any data or noise characters that are sitting in the input buffer of the asynchronous line before the line is activated, use the flush-at-activation command in line configuration mode. To keep any data or noise characters that are sitting in the input buffer of the asynchronous line before the line is activated, use the no form of this command.
flush-at-activation
no flush-at-activation
Syntax Description
This command has no keywords or arguments.
Defaults
Enabled by default.
Command Modes
Line configuration
Command History
Usage Guidelines
For an incoming call on a line configured with modem control (using the modem inout and modem dialin commands), the line will be activated when the data set ready (DSR) signal goes high and will be dropped when the DSR signal goes low. While the line is idle, its input buffer may receive characters; for example, modem result codes such as "NO CARRIER" or "RING" or line noise. Such characters are not useful to the line application. Flushing the line input buffer when the DSR goes high using the flush-at-activation command is the preferred behavior.
Note
On most Cisco IOS platforms, there may be up to a one-second delay between when the DSR signal goes high and Cisco IOS activates the line. Therefore, some valid data received from the line may be discarded when you issue the flush-at-activation command. If it is important to process this valid data rather than discarding it and the application is tolerant of receiving bad data, configure the no flush-at-activation command.
The application that is used determines whether the system can differentiate the valid data from the bad data or the system is tolerant of receiving any data. For example, consider that the application used is TCP over IP over PPP. PPP uses a Frame Check Sequence (FCS) in a data frame format to verify the integrity of the received data. If an invalid data pattern is delivered to a PPP receiver, PPP will discard it as a framing or FCS error. So the bad data will not be delivered to the higher layers. Even if some data is delivered up to IP and TCP, TCP has its own FCS which will reject bad data. Therefore, the application is tolerant of receiving the bad data that the line delivers.
Consider another application where incoming character data received from the line is delivered as TCP payload to a server running a pager application. Unless the pager application has implemented its own protocol to verify data integrity, this bad data may cause the pager not to be delivered, or to deliver bad data within the message payload to the receiving pager. So the bad data should not be delivered as payload to the line.
Where an upper-layer framed protocol such as PPP or Serial Line Internet Protocol (SLIP) is always used (asynchronous mode dedicated), the framed protocol may reach link status more quickly when you issue the no flush-at-activation command. Since the framed protocol discards any erroneous data received, you do not have to use the flush-at-activation command.
If the line application is not tolerant of receiving bad data; for example, when you are using character-mode username/password authentication, always use the flush-at-activation command. Otherwise, the bad data may trigger an application failure.
Note
The modem state STEADY_STATE is mapped to DSR high and TERMINATING is mapped to DSR low when asynchronous lines are the internal digital modem ports.Examples
The following example shows how to configure lines 1/0 through 1/59 to flush any data in their input buffers when the lines are activated:
Router(config)# line 1/0 1/59Router(config-line)# flush-at-activationRelated Commands
force-local-chap
To force the L2TP network server (LNS) to reauthenticate the client, use the force-local-chap command in VPDN group configuration mode. To disable reauthentication, use the no form of this command.
force-local-chap
no force-local-chap
Syntax Description
This command has no arguments or keywords.
Defaults
Proxy authentication. The Challenge Handshake Authentication Protocol (CHAP) response to the Layer 2 Transport Protocol access concentrator (LAC) authentication challenge is passed to the LNS.
Command Modes
VPDN group configuration
Command History
Usage Guidelines
You must enable the accept-dialin command on the VPDN group before you can use the force-local-chap command. Removing the accept-dialin command will remove the force-local-chap command from the VPDN group.
This command is used only if CHAP authentication is enabled for PPP (using the ppp authentication chap command). This command forces the LNS to reauthenticate the client in addition to the proxy authentication that occurs at the LAC. If the force-local-chap command is used, then the authentication challenge occurs twice. The first challenge comes from the LAC and the second challenge comes from the LNS. Some PPP clients may experience problems with double authentication. If this occurs, authentication challenge failures may be seen if the debug ppp authentication command is enabled.
Examples
The following example enables CHAP authentication at the LNS:
vpdn-group 1accept dialinprotocol l2tpvirtual-template 1terminate-from patforce-local-chapRelated Commands
framing
To select the frame type for the T1 or E1 data line, use the framing command in controller configuration mode.
T1 Line
framing {sf | esf}
E1 Line
framing {crc4 | no-crc4} [australia]
Syntax Description
Defaults
Super Frame is the default on a T1 line.
CRC4 frame is the default on an E1 line.
Command Modes
Controller configuration
Command History
Usage Guidelines
Use this command in configurations where the router or access server is intended to communicate with T1 or E1 fractional data line. The service provider determines which framing type, either the sf, esf, or crc4 keyword, is required for your T1/E1 circuit.
Examples
The following example selects Extended Super Frame as the T1 frame type:
framing esfRelated Commands
Defines the time slots that belong to each T1 or E1 circuit.
linecode
Selects the linecode type for T1 or E1 line.
group-range
To create a list of member asynchronous interfaces (associated with a group interface), use the group-range command in interface configuration mode. Use the no form of the command to remove an interface from the member list.
group-range low-end-of-range high-end-of-range
no group-range interface
Syntax Description
low-end-of-range
Beginning interface number to be made a member of the group interface.
high-end-of-range
Ending interface number to be made a member of the group interface.
Defaults
No interfaces are designated as members of a group.
Command Modes
Interface configuration
Command History
Usage Guidelines
Using the group-range command, you create a group of asynchronous interfaces that are associated with a group asynchronous interface on the same device. This group interface is configured by using the interface group-async command. This one-to-many structure allows you to configure all associated member interfaces by entering one command on the group interface, rather than entering this command on each interface. You can customize the configuration on a specific interface by using the member command.
Examples
The following example defines interfaces 2, 3, 4, 5, 6, and 7 as members of asynchronous group interface 0:
interface group-async 0group range 2 7Related Commands
initiate-to
To specify the IP address that will be tunneled to, use the initiate-to command in VPDN group configuration mode. To remove an IP address from the VPDN group, use the no form of the command.
initiate-to ip ip-address
no initiate-to [ip ip-address]
Syntax Description
Defaults
Disabled
Command Modes
VPDN group configuration
Command History
Usage Guidelines
Before you can use this command, you must enable one of the two request VPDN subgroups by using either the request dialin or request dialout command.
A LAC configured to request dial-in can be configured with multiple initiate-to commands to tunnel to more than one IP address.
An LNS configured to request dialout can only be configured with a single initiate-to command. If you enter a second initiate-to command, it will replace the original initiate-to command.
Examples
The following example configures VPDN group 1 to request an L2TP tunnel to the peer at IP address 10.3.2.1 for tunneling dialout calls from dialer pool 1.
vpdn-group 1request dialoutprotocol l2tppool-member 1imitate-to ip 10.3.2.1Related Commands
interface
To define the IP addresses of the server, use the interface command in interface configuration mode. To disable this function, use the no form of this command.
interface name-tag
no interface name-tag
Syntax Description
name-tag
The logic name to identify the server configuration so that multiple entries of server configuration can be entered.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Each server can have multiple entries of IP addresses or aliases.
Related Commands
interface bri
To configure a BRI interface and enter interface configuration mode, use the interface bri command in global configuration mode.
Cisco 7200 series and 7500 series routers
interface bri number
interface bri slot/port
Cisco 7200 series and 7500 series routers with subinterfaces
To configure a BRI subinterface only, use the following forms of the interface bri command in global configuration mode:
interface bri number.subinterface-number [multipoint | point-to-point]
interface bri slot/port.subinterface-number [multipoint | point-to-point]
To specify the BRI interface that is created by enabling X.25 on a specified ISDN BRI interface, use the interface bri command with a subinterface 0 specification:
interface bri number:0
interface bri slot/port:0
Syntax Description
Defaults
The default mode for subinterfaces is multipoint.
Command Modes
Global configuration
Command History
Usage Guidelines
Subinterfaces can be configured to support partially meshed Frame Relay networks. (Refer to the Frame Relay chapters in the Cisco IOS Wide-Area Networking Configuration Guide.)
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:
interface bri 0encapsulation pppno keepalivedialer map ip 131.108.36.10 name EB1 234dialer map ip 131.108 36.9 name EB2 456dialer-group 1isdn spid1 41346334600101 4633460isdn spid2 41346334610101 4633461isdn T200 1000ppp authentication chapThe following example creates a BRI 0:0 interface for X.25 traffic over the D channel and then configures the new interface to carry X.25 traffic:
interface bri0isdn x25 dchannelisdn x25 static-tei 8!interface bri0:0ip address 10.1.1.2 255.255.255.0x25 address 31107000000100x25 htc 1x25 suppress-calling-addressx25 facility windowsize 2 2x25 facility packetsize 256 256x25 facility throughput 9600 9600x25 map ip 10.1.1.3 31107000000200Related Commands
interface dialer
To define a dialer rotary group, use the interface dialer command in global configuration mode.
interface dialer number
Syntax Description
Defaults
No dialer rotary groups are predefined.
Command Modes
Global configuration
Command History
Usage Guidelines
Dialer rotary groups allow you to apply a single interface configuration to a set of physical interfaces. This allows a group of interfaces to be used as a pool of interfaces for calling many destinations.
Once the interface configuration is propagated to a set of interfaces, those interfaces can be used to place calls using the standard DDR criteria. When multiple destinations are configured, any of these interfaces can be used for outgoing calls.
Dialer rotary groups are useful in environments that require multiple calling destinations. Only the rotary group needs to be configured with the dialer map commands. The only configuration required for the interfaces is the dialer rotary-group command indicating that each interface is part of a dialer rotary group.
Although a dialer rotary group is configured as an interface, it is not a physical interface. Instead, it represents a group of interfaces. Interface configuration commands entered after the interface dialer command will be applied to all physical interfaces assigned to specified rotary groups. Individual interfaces in a dialer rotary group do not have individual addresses. The dialer interface has a protocol address, and that address is used by all interfaces in the dialer rotary group.
Examples
The following example identifies interface dialer 1 as the dialer rotary group leader. Interface dialer 1 is not a physical interface, but represents a group of interfaces. The interface configuration commands that follow apply to all interfaces included in this group.
interface dialer 1encapsulation pppauthentication chapdialer in-bandip address 1.2.3.4dialer map ip 1.2.2.5 name YYY 14155553434dialer map ip 1.3.2.6 name ZZZinterface multilink
To create a multilink bundle or enter multilink interface configuration mode, use the interface multilink command in global configuration mode. Use the no form of this command to remove a multilink bundle.
interface multilink group-number
no interface multilink
Syntax Description
Defaults
No interfaces are configured.
Command Modes
Global configuration
Command History
Examples
The following example creates multilink bundle 1:
interface multilink 1ip address 192.168.11.4 255.255.255.192encapsulation pppppp multilinkkeepaliveRelated Commands
interface serial
To specify a serial interface created on a channelized E1 or channelized T1 controller (for ISDN PRI, channel-associated signalling, or robbed-bit signalling), use the interface serial command in global configuration mode.
Cisco 7200 series and Cisco 7500 series routers
interface serial slot/port:timeslot
Cisco AS5200 series and Cisco 4000 series access servers
interface serial number:timeslot
Syntax Description
Defaults
You must explicitly specify a serial interface.
Command Modes
Global configuration
Command History
Usage Guidelines
The D channel is always the :23 channel for T1 and the :15 for E1.
Examples
The following example configures channel groups on time slots 1 to 11 and ISDN PRI on time slots 12 to 24 of T1 controller 0. Then the examples configures the first two channel groups as serial interfaces 0:0 and 0:1.
controller t1 0channel-group 0 timeslot 1-6channel-group 1 timeslot 7channel-group 2 timeslot 8channel-group 3 timeslot 9-11pri-group timeslots 12-24!interface serial 0:0ip address 131.108.13.2 255.255.255.0encapsulation ppp!interface serial 0:1ip address 131.108.13.3 255.255.255.0encapsulation pppThe following example configures ISDN PRI on T1 controller 4/1 and then configures the D channel on the resulting serial interface 4/1:23:
controller t1 4/1framing crc4linecode hdb3pri-group timeslots 1-24interface serial 4/1:23ip address 131.108.13.1 255.255.255.0encapsulation pppRelated Commands
interface virtual-template
To create a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces, use the interface virtual-template command in global configuration mode.
interface virtual-template number
Syntax Description
Defaults
Disabled. No virtual template number is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
A virtual template interface is used to provide the configuration for dynamically created virtual access interfaces. It is created by users and can be saved in nonvolatile RAM (NVRAM).
Once the virtual template interface is created, it can be configured in the same way as a serial interface.
Virtual template interfaces can be created and applied by various applications such as Virtual Profiles, virtual private dialup networks (VPDN), PPP over ATM, protocol translation, and Multichassis Multilink PPP (MMP).
Examples
The following example creates and configures virtual template interface 1:
interface virtual-template 1ip unnumbered ethernet 0ppp multilinkppp authentication chapip address negotiated
To specify that the IP address for a particular interface is obtained via PPP/IPCP (IP Control Protocol) address negotiation, use the ip address negotiated command in interface configuration mode. Use the no form of this command to disable this feature.
ip address negotiated [previous]
no ip address negotiated [previous]
Syntax Description
Defaults
No default behavior or values.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the ip address negotiated interface command to enable a Cisco router to automatically negotiate its own registered WAN interface IP address from a central server (via PPP/IPCP) and to enable all remote hosts to access the global Internet using this single registered IP address.
Examples
The following example configures an asynchronous interface (interface async1) to obtain its IP address via PPP/IPCP address negotiation:
interface async1ip address negotiatedencapsulation pppRelated Commands
ip address-pool
To enable a global default address pooling mechanism used to supply IP addresses to dial-in asynchronous, synchronous, or ISDN point-to-point interfaces, use the ip address-pool command in global configuration mode. To disable IP address pooling globally on all interfaces with the default configuration, use the no form of this command.
ip address-pool {dhcp-proxy-client | local}
no ip address-pool
Syntax Description
Command Default
IP address pooling is disabled globally.
Command Modes
Global configuration
Command History
Usage Guidelines
The global default IP address pooling mechanism applies to all interfaces that have been left in the default setting of the peer default ip address command.
If any peer default ip address command other than peer default ip address pool (the default) is configured, the interface uses that mechanism and not the global default mechanism. Thus all interfaces can be independently configured, or left unconfigured so that the global default configuration applies. This flexibility minimizes the configuration effort on the part of the administrator.
Examples
The following example specifies the DHCP proxy client mechanism as the global default mechanism for assigning peer IP addresses:
ip address-pool dhcp-proxy-clientThe following example specifies a local IP address pool named "default" as the global default mechanism for all interfaces that have been left in their default setting:
ip address-pool localRelated Commands
ip alias
To assign an IP address to the service provided on a TCP port, use the ip alias command in interface configuration mode. Use the no form of this command to remove the specified address for the router.
ip alias ip-address tcp-port
no ip alias ip-address
Syntax Description
Defaults
No default behavior or values.
Command Modes
Interface configuration
Command History
Usage Guidelines
A user attempting to establish a connection is connected to the first free line in a rotary group using the Telnet protocol.
The IP address must be on the same network or subnet as the router's main address, and must not be used by another host on that network or subnet. Connecting to the IP address has the same effect as connecting to the router's main address, using tcp-port as the TCP port.
You can use the ip alias command to assign multiple IP addresses to the router. For example, in addition to the primary alias address, you can specify addresses that correspond to lines or rotary groups. Using the ip alias command in this way makes the process of connecting to a specific rotary group transparent to the user.
When asynchronous mode is implemented, the Cisco IOS software creates the appropriate IP aliases, which map the asynchronous addresses for the lines to which they are connect. This process is automatic and does not require configuration.
Examples
The following example configures connections to IP address 172.30.42.42 to act identically to connections made to the server's primary IP address on TCP port 3001. In other words, a user is connected to the first free line on port 1 of the rotary group that uses the Telnet protocol.
ip alias 172.30.42.42 3001ip dhcp-server
To specify which Dynamic Host Configuration Protocol (DHCP) servers to use on your network, or to specify the IP address of one or more DHCP servers available on the network, use the ip dhcp-server command in global configuration mode. Use the no form of the command to remove a DHCP server's
