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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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Table Of Contents
multilink
To limit the total number multilink PPP (MLP) sessions for all virtual private dialup network (VPDN) multilink users, enter the multilink command in VPDN group configuration mode. To remove the MLP session limit, enter the no form of this command.
multilink {bundle bundles | link links}
no multilink {bundle bundles | link links}
Syntax Description
Command Default
No MLP session limit is set.
Command Modes
VPDN group configuration
Command History
12.0(4)XI
This command was introduced.
12.0(5)T
This command was integrated into Cisco IOS Release 12.0(5)T.
Usage Guidelines
Use the multilink VPDN group configuration command to limit the total number of sessions for all MLP users. Each user requires one bundle, regardless if the user is a remote modem client or an ISDN client.
One modem client using one B channel requires one link. One ISDN BRI node may require up to two links for one BRI line connection. The second B channel of an ISDN BRI node comes up when the maximum threshold is exceeded.
Examples
The following example configures a VPDN group called group1 to initiate Layer 2 Tunnel Protocol (L2TP) tunnels to the tunnel server at IP address 10.2.2.2. Ten MLP bundles are configured for users that dial in to the domain cisco.com. Each bundle is configured to support a maximum of 5 links, limiting the total number of MLP sessions to 50.
Router(config)# vpdn-group group1Router(config-vpdn)# request-dialinRouter(config-vpdn-req-in)# protocol l2tpRouter(config-vpdn-req-in)# domain cisco.comRouter(config-vpdn-req-in)# exitRouter(config-vpdn)# initiate-to ip 10.2.2.2Router(config-vpdn)# multilink bundle 10Router(config-vpdn)# multilink link 5Related Commands
multilink bundle-name
To select a method for naming multilink bundles, use the multilink bundle-name global configuration command. To remove the selection method, use the no form of this command.
multilink bundle-name {authenticated | endpoint | both}
no multilink bundle-name {authenticated | endpoint | both}
Syntax Description
Defaults
Authenticated name of the peer.
Command Modes
Global configuration
Command History
Usage Guidelines
The authenticated keyword defines the selection criteria for the bundle name as the authenticated name, the endpoint discriminator if the link is not authenticated, or the caller ID if neither an authenticated name nor an endpoint is supplied.
The endpoint keyword defines the selection criteria for the bundle name as the endpoint discriminator, the authenticated name if no endpoint is supplied, or the caller ID if neither an authenticated name nor an endpoint is supplied.
The both keyword defines the selection criteria for the bundle name as an authenticated name-endpoint discriminator pair, the authenticated name if no endpoint is supplied, the endpoint discriminator if the link is not authenticated, or the caller ID if neither an authenticated name nor an endpoint is supplied.
Examples
The following example sets the selection criteria for the multilink bundle name as the endpoint discriminator:
multilink bundle-name endpointmultilink max-fragments
To set the maximum number of fragments a packet will be segmented into before being sent over the bundle, use the multilink max-fragments interface configuration command. To reset fragmentation to the default value, use the no form of this command.
multilink max-fragments fragments
no multilink max-fragments
Syntax Description
Defaults
16 fragments
Command Modes
Interface configuration
Command History
Usage Guidelines
Use the multilink max-fragments command to control the number of fragments into which a PPP frame may be fragmented. The multilink max-fragments command has been used to disable fragmentation entirely by setting the number of fragments to 1. This setting is better accomplished using the no ppp multilink fragmentation command.
The limit set using the multilink max-fragments command applies only when Multilink PPP (MLP) is fragmenting packets in a mode where it is constraining the number of fragments rather than the size of the fragments. See the description about fragmentation modes in the section "Usage Guidelines" of the ppp multilink fragment-delay command for more details.
Examples
The following example uses the multilink max-fragments command to fragment each frame into no more than four fragments:
multilink max-fragments 4Related Commands
ppp multilink fragmentation
Enables packet fragmentation.
ppp multilink fragment-delay
Specifies a maximum size, in units of time, for packet fragments on an MLP bundle.
multilink virtual-template
To specify a virtual template from which the specified Multilink PPP (MLP) bundle interface can clone its interface parameters, use the multilink virtual-template command in global configuration mode.
multilink virtual-template number
Syntax Description
Defaults
Disabled. No template number is defined.
Command Modes
Global configuration
Command History
Usage Guidelines
Configuring a specific IP address in a virtual template can result in the establishment of erroneous routes and the loss of IP packets.
Examples
The following example specifies an MLP virtual template to be used and then defines the template to be applied to an MLP bundle interface:
multilink virtual-template 1ip local pool default 2.2.2.2interface virtual-template 1ip unnumbered ethernet 0encapsulation pppppp multilinkppp authentication chapRelated Commands
multilink-group
To designate an interface as part of a multilink leased line bundle, use the multilink-group command in interface configuration mode. To remove an interface from a bundle, use the no form of this command.
multilink-group group-number
no multilink-group
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
All interfaces in a multilink bundle must have the same bandwidth.
Examples
The following example designates serial interface 1 as part of multilink bundle 1:
interface serial 1encapsulation pppmultilink-group 1ppp multilinkppp authentication chappulse-time 3Related Commands
netbios nbf
To enable the NetBIOS Frames Protocol (NBF) on an interface, use the netbios nbf command in interface configuration mode. Use the no form of this command to disable NetBIOS Frames Protocol support on an interface.
netbios nbf
no netbios nbf
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Examples
The following example enables NetBIOS Frames Protocol on asynchronous interface 1 (connected to remote access client using a NetBEUI application) and Ethernet interface 0 (connected to the remote router):
interface async 1netbios nbfinterface ethernet 0netbios nbfRelated Commands
network-clock-priority
To specify the clock-recovery priority for the BRI voice ports in a BRI voice module (BVM), use the network-clock-priority command in interface configuration mode . Use the no form of this command to restore the default (low) clock-recovery priority.
network-clock-priority {low | high}
no network-clock-priority {low | high}
Syntax Description
low
The BRI port is second priority to recover clock.
high
The BRI port is first priority to recover clock.
Defaults
Each BRI voice port has low clock-recovery priority.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command is supported only on the Cisco MC3810.
This command is only valid for BRI ports configured as TE. It allows you to select which PINX (PBX) is the first-priority clock source.
This command becomes effective only when the BVM is the clock source for the Cisco MC3810; this happens in three ways:
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When the BVM is specified as the first-priority network clock source through the network-clock-select command.
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The BRI voice port supplying clock operates as a line source; if there are other BRI voice ports configured as TE, they operate in loop-timed mode.
Regardless of the network-clock-priority setting, the first TE-configured BRI voice port that becomes active is automatically chosen to supply clock. The clock source does not change if another BRI voice port configured for network-clock-priority high becomes active.
If the chosen clocking port becomes inactive, the system searches for clock on the active TE-configured ports in the following order:
1.
2.
If the originally chosen port then reactivates, it resumes its role as clock source regardless of its network-clock-priority setting.
If you enter either the no network-clock-priority low or the no network-clock-priority high command, the network clock priority defaults to low.
Examples
The following example configures BRI voice port 1 as a first priority clock source:
interface bri 1network-clock-priority highRelated Commands
network-clock-select
To specify selection priority for the clock sources, use the network-clock-select command in global configuration mode. Use the no form of this command to cancel the network clock selection.
network-clock-select priority {serial 0 | system | bvm | controller}
no network-clock-select priority {serial 0 | system | bvm | controller}
Syntax Description
Defaults
No network clock source is specified.
Command Modes
Global configuration
Command History
11.3MA
This command was introduced.
12.0(3)XG
The BVM as a possible network clock source was added.
Usage Guidelines
When an active clock source fails, the system chooses the next lower priority clock source specified by this command. When a higher-priority clock becomes available, the system automatically reselects the higher-priority clock source.
Note
Use the network-clock-select command to establish the clock-selection priority when there are multiple sources of line (network) clocking in a Cisco MC3810. Possible sources of line clocking for the Cisco MC3810 are the BRI voice module (BVM), the multiflex trunk module (MFT), and a serial port configured for clock rate line.
Examples
The following example sets a possible clock selection priority in a Cisco MC3810 with a digital voice module (DVM) installed:
network-clock-select 1 T1 0 network-clock-select 2 T1 1 network-clock-select 3 serial 0 network-clock-select 4 systemThe following example sets a possible clock selection priority in a Cisco MC3810 with a BRI voice module (BVM) installed:
network-clock-select 1 T1 0 network-clock-select 2 bvm network-clock-select 3 serial 0 network-clock-select 4 systemRelated Commands
number
To add a DNIS number to a dialer DNIS group, use the number command in DNIS group configuration mode followed by the specifying number. Use the no form of this command to remove a DNIS number from a DNIS group.
number number
no number number
Syntax Description
Defaults
No default behavior or values.
Command Modes
DNIS group configuration
Command History
Usage Guidelines
Use the number DNIS group configuration command to enter a DNIS number to a dialer DNIS group. The Cisco IOS software also includes a feature that streamlines the DNIS configuration process. By replacing any digit with an X (for example, issuing the number 555222121x command), clients dialing different numbers, such as 5552221214 or 5552221215, are automatically mapped to the same customer profile. The X variable is a place holder for the digits 1 through 9.
Examples
The following example shows a DNIS group called dnis_isp_1 and DNIS numbers 1234 and 5678 assigned to the DNIS group:
dialer dnis group dnis_isp_1number 1234number 5678Related Commands
pad
To log in to a packet assembler/disassembler (PAD), use the pad command in EXEC mode.
pad {x121-address | hostname} [/cud text] [/debug] [/profile name] [/quiet message] [/reverse] [/use-map]
Syntax Description
Command Modes
User EXEC
Command History
Usage Guidelines
The pad command supports one-word connections. You need not enter the pad command; just entering the address is enough to start the connection. A PAD can also be accessed and X.3 parameters configured with the x28 EXEC command, which uses the standard X.28 user interface.
You can have several PAD connections open at the same time and switch between them. You also can exit a connection and return to the user EXEC prompt at any point. To open a new connection, first exit the current connection by entering the escape sequence (Ctrl-Shift-6 then x [Ctrl^x] by default) to return to the EXEC prompt, then open the new connection. If the /use-map option is selected on the outgoing pad command, the x25 map pad command entries are searched for a matching X.121 destination address. If a match is found, the x25 map pad command entry options (such as CUD and idle) and facilities (such as packet in, packet out, win in, and win out) are applied to the outgoing PAD call.
To display information about packet transmission and X.3 PAD parameter settings, use the show x25 pad command.
To exit a session, simply log off the remote system. Then, terminate the active session by entering the exit command.
Examples
Use the ? command to display pad command options, as shown in this example:
router# pad / ?/cud Call user data/debug Debugging option/profile Use a defined X.3 profile/quiet Suppress informational messages/reverse X25 Address reverse/use-map Use x25 map pad command facilities for outgoing CallsThe following example starts a PAD session:
router> pad 123456789Trying 123456789...Openrouter>You can also access a PAD using standard X.28 commands. The following example enters X.28 mode with the x28 EXEC command and configures a PAD with the set X.3 parameter command. The set command sets the idle time delay to 40 seconds.
router# x28* set 4:40The following example uses the /use-map option to configure a larger window and packet size than the default specified on the interface, and it sets the VC idle time to 2 seconds. Notice that the map values are used rather than the interface default values.
Router-A(config-if)# x25 map pad 2194441 cud gmcmilla windowsize 7 7 packetsize 1024 1024 idle 2Router-A(config-if)# endRouter-A#%SYS-5-CONFIG_I: Configured from console by console.Router-A# pad 2194441 /cud gmcmillla /use-mapTrying 2194441....Open06:31:12: pad_open_connection: found a matching x25 map pad06:31:12: Serial1: X.25 O R1 Call (22) 8 lci 102406:31:12: From(7): 2191111 To(7): 219444106:31:12: Facilities: (6)06:31:12: Packet sizes: 1024 102406:31:12: Window sizes: 7 706:31:12: Call User Data (12): 0x01000000 (pad)06:31:12: Serial1: X.25 I R1 Call Confirm (5) 8 lci 102406:31:12: From(0): To(0):06:31:12: Facilities: (0)06:31:12: PAD0: Call completedRelated Commands
Automatically translates the request to another outgoing protocol connection type when an X.25 connection request to a particular destination address is received.
peer default ip address
To specify an IP address, an address from a specific IP address pool, or an address from the Dynamic Host Configuration Protocol (DHCP) mechanism to be returned to a remote peer connecting to this interface, use the peer default ip address command in interface configuration mode. Use the no form of this command to disable a prior peer IP address pooling configuration on an interface.
To remove the default address from your configuration, use the no form of this command also.
peer default ip address {ip-address | dhcp | pool [pool-name-list]}
no peer default ip address
Syntax Description
Defaults
The default is pool.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to point-to-point interfaces that support the PPP or Serial Line Internet Protocol (SLIP) encapsulation. This command sets the address used on the remote (PC) side.
Note
This command allows an administrator to configure all possible address pooling mechanisms on a interface-by-interface basis.
The peer default ip address command can override the global default mechanism defined by the ip address-pool command on an interface-by-interface basis, as follows:
•
•
•
•
Examples
The following command specifies that this interface will use a local IP address pool called pool3:
peer default ip address pool pool3The following command specifies that this interface will use the IP address 172.140.34.21:
peer default ip address 172.140.34.21The following command reenables the global default mechanism to be used on this interface:
peer default ip address poolThe following example specifies address 192.31.7.51 for async interface 6:
line 20speed 115200interface async 6peer default ip address 192.31.7.51Related Commands
pool-member
To assign a request-dialout virtual private dialup network (VPDN) subgroup to a dialer pool, use the pool-member command in request-dialout configuration mode. To remove the request-dialout VPDN subgroup from a dialer pool, use the no form of this command
pool-member pool-number
no pool-member [pool-number]
Syntax Description
Defaults
Disabled
Command Modes
Request-dialout configuration
Command History
Usage Guidelines
You must first enable the protocol l2tp on the request-dialout VPDN subgroup before you can enable the pool-member command. Removing the protocol l2tp command will remove the pool-member command from the request-dialout subgroup.
You can only configure one dialer profile pool (using the pool-member command) or dialer rotary group (using the rotary-group command). If you attempt to configure a second dialer resource, you will replace the first dialer resource in the configuration.
Examples
The following example configures VPDN group 1 to request L2TP dialout to IP address 172.5.4.6 using dialer profile pool 1 and identifying itself using the local name harold.
vpdn-group 1request-dialoutprotocol l2tppool-member 1initiate-to ip 172.5.4.6local name haroldRelated Commands
pool-range
To assign a range of modems to a modem pool, use the pool-range command in modem-pool configuration mode.
Cisco AS5200 and Cisco AS5300 access servers
pool-range number-number
Syntax Description
Defaults
Disabled. All modems are configured to be part of the system default modem pool.
Command Modes
Modem pool configuration
Command History
Usage Guidelines
For a complete description of modem pools and how they are configured on Cisco access servers, see the command reference page for the modem-pool command.
Replace the number-number variable with the modem TTY line numbers that correspond with the range of modems you want in the modem pool. TTY line numbers start from 1, which map to modem numbers that start from 0. For example, if you want to include modems 1/0 through 1/23 in a pool range, use the TTY line numbers 1 to 24. To verify the modem to TTY line numbering scheme, use the show modem slot/port command.
Note
Examples
The following example assigns modem TTY line numbers 30 to 50 to a modem pool. The DNIS number is set to 2000. The customers dialing 2000 are guaranteed access to 21 modems. The 22nd client to dial in is refused connectivity because the maximum number of allowable connections is exceeded.
modem-pool v90servicepool-range 30-50called-number 2000 max-conn 21exitThe following configuration rejects the pool-range 30 command, because modem TTY line 30 is already a member of the modem pool v90service, which was configured in the previous example. Each modem in the access server is automatically assigned to a unique TTY line. TTY line numbers are assigned according to your shelf, slot, or port hardware configuration.
modem-pool v34servicepool-range 30% TTY 30 is already in another pool.Related Commands
ppp
To start an asynchronous connection using PPP, use the ppp command in EXEC mode.
ppp {/default | {remote-ip-address | remote-name} [@tacacs-server]} [/routing]
Syntax Description
Command Modes
EXEC
Command History
Usage Guidelines
When you connect from a remote node computer to an EXEC session on the access server and want to connect from the access server to a device on the network, issue the ppp command.
If you specify an address for the TACACS server (either /default or tacacs-server), the address must be the first parameter in the command after you type ppp. If you do not specify an address or enter the default keyword, you are prompted for an IP address or host name. You can enter the default keyword at this point.
To terminate a session, disconnect from the device on the network using the command specific to that device. Then, exit from the EXEC by using the exit command.
Examples
The following example shows a line that is in asynchronous mode using PPP encapsulation. The PC's name (ntpc in this example) must be in the Domain Name System (DNS) so that it can be resolved to a real IP address). The PC must be running a terminal emulator program.
ppp ntpc@server1ppp bap call
To set PPP Bandwidth Allocation Protocol (BACP) call parameters, use the ppp bap call command in interface configuration mode. Use the no form of this command to disable processing of a specific type of incoming connection.
ppp bap call {accept | request | timer seconds}
no ppp bap call {accept | request | timer}
Syntax Description
Defaults
accept—Peers can initiate the addition of links to a multilink bundle.
The timer is disabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command can be included in a virtual interface template for configuring virtual interfaces or can be used to configure a dialer interface.
Examples
The following example configures a dialer interface to accept calls. Accepting calls is the default, but the command is included for the sake of the example.
interface dialer 1ip unnumbered ethernet 0encapsulation pppppp multilink bapppp bap call acceptppp bap link types isdn analogdialer load threshold 30ppp bap timeout pending 60Related Commands
ppp bap callback
To enable PPP Bandwidth Allocation Protocol (BACP) callback and set callback parameters, use the ppp bap callback command in interface configuration mode. Use the no form of this command to remove the PPP BACP callback configuration.
ppp bap callback {accept | request | timer seconds}
no ppp bap callback {accept | request | timer}
Syntax Description
Defaults
Callback is disabled and no callback parameters are set.
The timer is disabled.
Command Modes
Interface configuration
Command History
Examples
The following example configures a BRI interface for active mode BACP:
interface bri 0ip unnumbered ethernet 0dialer load-threshold 10 eitherdialer map ip 172.21.13.101 name bap-peer 14085778899encapsulation pppppp multilink bapppp bap call requestppp bap callback acceptno ppp bap call acceptno ppp bap drop acceptppp bap pending timeout 30ppp bap number default 5664567ppp bap number secondary 5664568Related Commands
ppp bap drop
To set parameters for removing links from a multilink bundle, use the ppp bap drop command in interface configuration mode. Use the no form of this command to disable a specific type of default processing.
ppp bap drop {accept | after-retries | request | timer seconds}
no ppp bap drop {accept | after-retries | request | timer}
Syntax Description
Defaults
accept, request: Peers can initiate link removal and this router also can initiate link removal.
no ppp bap drop after-retries: The link is not dropped when there is no response to drop requests.
timer: Disabled; no default value is defined.
Command Modes
Interface configuration
Command History
Usage Guidelines
The no ppp bap drop accept command disables the router's ability to respond favorably to link drop requests from a peer. However, the router can still remove the link when it receives such requests.
The no ppp bap drop after-retries command is the default behavior; the ppp bap drop after-retries command must be entered explicitly to be effective.
The no ppp bap drop request command disables the router's ability to send link drop requests to a peer. However, the peer can still remove the link on its own behalf; for example, when there is too little traffic to justify keeping the link up.
The ppp bap max command specifies the maximum number of requests and retries.
Examples
The following partial example sets a 60-second wait between drop requests:
ppp bap drop timer 60Related Commands
ppp bap link types
To specify the types of links that can be included in a specific multilink bundle, use the ppp bap link types command in interface configuration mode. Use the no form of this command to remove a type of interface that was previously allowed to be added.
ppp bap link types [isdn] [analog]
no ppp bap link types [isdn] [analog]
Syntax Description
isdn
(Optional) ISDN interfaces can be added to a multilink bundle. This is the default.
analog
(Optional) Asynchronous serial interfaces can be added to a multilink bundle.
Defaults
isdn
Command Modes
Interface configuration
Command History
Usage Guidelines
The choice of keywords must suit the interfaces configured for Multilink PPP. For example, if you have configured a dialer rotary with only ISDN interfaces, only the isdn keyword would be appropriate. If the configuration allows both ISDN and asynchronous interfaces, both isdn and analog keywords could be used; the multilink bundle could then consist of both ISDN and asynchronous links. Bandwidth Allocation Protocol (BACP) dynamically determines which interfaces are applicable.
Examples
The following example configures a dialer interface for passive mode BACP and for both ISDN and asynchronous serial links:
interface dialer 1ip unnumbered ethernet 0encapsulation pppppp multilink bapppp bap call acceptppp bap link types isdn analogdialer load threshold 30ppp bap timeout pending 60Related Commands
Displays the configuration settings and run-time status for a multilink bundle.
Enables PPP BACP callback and set callback parameters.
ppp bap max
To set upper limits on the number of retransmissions for PPP Bandwidth Allocation Protocol (BACP), use the ppp bap max command in interface configuration mode. Use the no form of this command to remove any retry limit.
ppp bap max {dial-attempts number | ind-retries number | req-retries number | dialers number}
no ppp bap max {dial-attempts | ind-retries | req-retries | dialers number}
Syntax Description
Defaults
1 dial attempt
3 indication retries
3 request retries
5 searches for free dialers
Command Modes
Interface configuration
Command History
Usage Guidelines
In compliance with RFC 2125, the no form of this command explicitly removes any status indication retry limit and is displayed in the router configuration.
The ppp bap max dialers command works in conjunction with the interface commands dialer rotor and dialer priority, which can be used to determine free dialers based upon the priority or the best available. Dialers include all interfaces that are configured under the dialer group leader (the dialer interface itself). The dialer group leader is displayed as the Master Interface in the show ppp bap group output.
BAP bases its link type and phone number decisions upon the ordering of the interfaces. This is suited to a mixed media environment of both ISDN and analog interfaces, where it may be desirable to choose the ISDN link over the asynchronous or vice versa.
Note that this also will limit the number of potential phone numbers which can be included in a CallResponse or CallbackRequest; the maximum number is limited to 20. For example, ten BRI interfaces with two numbers per interface.
Examples
The following partial example accepts the default number of attempts to dial a number and the default number of indication retries, but configures a limit of four times to send requests:
ppp bap max req-retries 4Related Commands
Sets the priority of an interface in a dialer rotary group.
Specifies the method for identifying the outbound line to be used for ISDN or asynchronous DDR calls.
Sets parameters for removing links from a multilink bundle.
Validates peer requests to add or remove links against the current bundle load and the defined dialer load threshold.
Specifies nondefault timeout values for PPP BACP pending actions and responses.
show ppp bap group
Displays the configuration settings and run-time status for a multilink bundle.
ppp bap monitor load
To validate peer requests to add or remove links against the current bundle load and the defined dialer load threshold, use the ppp bap monitor load command in interface configuration mode. Use the no form of this command to specify that incoming link addition requests are not to be subject to the bundle load threshold.
ppp bap monitor load
no ppp bap monitor load
Syntax Description
This command has no arguments or keywords.
Defaults
Enabled
Command Modes
Interface configuration
Command History
Usage Guidelines
If the load is being monitored and the incoming peer requests that a link be dropped when the current traffic load is above the dialer load (that is, there is enough traffic to justify the current number of links), the router will not drop the link. In addition, when the traffic falls below the threshold, BACP tries to drop a link.
The no form of the command indicates that incoming peer requests to add a link are not subject to the bundle load threshold. However, other criteria must be met before a favorable response is sent.
Examples
The following partial example configures BACP not to validate peer requests against the current bundle load and the configured dialer load threshold:
no ppp bap monitor loadRelated Commands
Configures bandwidth on demand by setting the maximum load before the dialer places another call to a destination.
ppp bap number
To specify a local telephone number that peers can dial to establish a multilink bundle, use the ppp bap number command in interface configuration mode. Use the no form of this command to remove a previously configured number.
ppp bap number {default phone-number | secondary phone-number | prefix prefix-number}
no ppp bap number {default phone-number | secondary phone-number | prefix prefix-number}
ppp bap number {format national | subscriber}
no ppp bap number {format national | subscriber}
Syntax Description
Defaults
No base number is provided.
Command Modes
Interface configuration
Command History
11.3
This command was introduced.
11.3T
The following keywords were added:
•
•
Usage Guidelines
Use this command to supply a local default number to be exchanged between peers in order to establish a multilink bundle.
This command is applicable on both the dialer interface and the individual physical interfaces.
If a peer requests that a number be supplied and no PPP BACP default number is defined, it might not be possible for the peer to access the interface. However, the peer can access the interface if it has the number already or the number it dialed originally is the same as the number for establishing a Multilink PPP bundle.
Note
For example, if the remote peer dialed 2157659876, and the ppp bap number command had the default number 2157659912, the local router would respond "3 | 912." In the response, a vertical bar ( | ) is used to divide the number of digits to change from the number sequence to use instead. In the "3 | 912" response, the local router instructs the calling interface to replace the right-most three digits with "912" for BACP.This command is used by the client side for dialing instructions when communicating with the server. Use the prefix keyword on the Always On/Dynamic ISDN (AO/DI) client side to specify what will precede any number dialed to a multilink peer. For example, the client issues a call request to the server whereby the server issues a call response which includes the dialing number the client should use and the format this number should be in (national or subscriber). The client then dials the number supplied by the server, preceded by any prefix information contained in the ppp bap number prefix command. Figure 2 shows an overview about the information exchange between the client and the server.
Figure 2 Client and Server Response Sequence
Use the format keyword on the AO/DI server side to specify how many digits should be returned by BAP. BAP will return the numbers based on either a national or subscriber format. The value that is returned is preceded by the prefix before dialing occurs. For example, if the format national keywords are configured, then the national format (which is equivalent to 10 digits) is returned by BAP (during BAP negotiation) from the server.
Note
Examples
In the following example, the AO/DI client uses a ppp bap prefix value of 9, which indicates that the dialed number of 5551234 will be preceded by a 9. The number that is actually dialed is 95551234. The AO/DI server uses a subscriber format, which indicates that when the client asks the server for the numbers to dial, BAP will return 7-digits.
Client router
interface dialer1ppp bap number prefix 9Server Router
interface dialer1ppp bap number format subscriberppp bap number default 5555678In the following example, the AO/DI client uses a ppp bap prefix value of 1, which indicates that the dialed number of 5551234 will be preceded by a 1. The number that is actually dialed is 19195555678 because the server is using a national format, and BAP therefore, returns 10-digits.
Client Router
interface dialer1ppp bap number prefix 1Server Router
interface dialer1ppp bap number format nationalppp bap number default 9195555678The following example configures a physical interface with both a default number and a secondary number:
interface bri 0ip unnumbered ethernet 0dialer load-threshold 10 eitherdialer map ip 172.21.13.101 name bap-peer 14085778899encapsulation pppppp multilink bapppp bap call requestppp bap callback acceptno ppp bap call acceptno ppp bap drop acceptppp bap pending timeout 30ppp bap number default 5664567ppp bap number secondary 5664568In the following example, a PRI with no BAP number defined accepts incoming dial attempts. The PRI interface has no base phone number defined, so each attempt to add a link would result in a delta of zero being provided to the calling peer. The calling peer should then dial the same number as it originally used to establish the bundle.
interface serial 0:23ip unnumbered Ethernet0encapsulation pppdialer in-banddialer idle-timeout 300dialer-group 1no fair-queueno cdp enableppp authentication chapppp multilink bapppp bap call acceptppp bap callback requestppp bap timeout pending 20ppp bap timeout response 2ppp bap max dial-attempts 2ppp bap monitor loadIn the following example, a BRI interface with no BAP number defined initiates outgoing dial attempts. The BRI interface has no base phone number defined, so the number that it uses to establish the bundle is that from the dialer map, and all phone delta operations are applied to that number.
interface bri 0ip unnumbered Ethernet0encapsulation pppdialer in-banddialer idle-timeout 300dialer map ip 10.1.1.1 name bap_peer speed 56 19998884444dialer-group 1no fair-queueno cdp enableppp authentication chapppp multilink bapppp bap call requestppp bap timeout pending 20ppp bap timeout response 2ppp bap max dial-attempts 2ppp bap monitor loadRelated Commands
Enables PPP BACP callback and set callback parameters.
Displays the configuration settings and run-time status for a multilink bundle.
ppp bap timeout
To specify nondefault timeout values for PPP Bandwidth Allocation Protocol (BACP) pending actions and responses, use the ppp bap timeout command in interface configuration mode. Use the no form of this command to reset the response timeout to the default value, or to remove a pending timeout entirely.
ppp bap timeout {pending seconds | response seconds}
no ppp bap timeout {pending | response}
Syntax Description
Defaults
Enabled
pending—20 seconds
response—3 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
The no ppp bap timeout response command resets the timer to the default value.The no ppp bap timeout pending command removes the pending-action timeout entirely (in compliance with the BACP specification).
Examples
The following example configures BACP to wait 45 seconds before timing out pending actions:
interface dialer 1ip unnumbered ethernet 0encapsulation pppppp multilink bapppp bap call acceptppp bap link types isdn analogdialer load threshold 30ppp bap timeout pending 45Related Commands
ppp bridge appletalk
To enable half-bridging of AppleTalk packets across a serial interface, use the ppp bridge appletalk command in interface configuration mode. Use the no form of this command to disable AppleTalk packet half-bridging.
ppp bridge appletalk
no ppp bridge appletalk
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
When you configure a serial or ISDN interface for half bridging, you configure it to function as a node on an Ethernet subnetwork. It communicates with a bridge on the subnetwork by sending and receiving bridge packets. The serial or ISDN interface converts bridge packets to routed packets and forwards them, as needed.
The serial interface must be configured with an AppleTalk address for communication on the Ethernet subnetwork, and the AppleTalk address must have the same AppleTalk cable range as the bridge.
You cannot configure a serial interface for both half-bridging and for transparent bridging.
No more than one half-bridge should be on any subnetwork.
Examples
The following example configures serial interface 0 for half-bridging of AppleTalk. The remote bridge and other Ethernet nodes must be on the same network.
interface serial 0ppp bridge appletalkappletalk cable-range 301-301appletalk zone remote-lanRelated Commands
ppp bridge ip
To enable half-bridging of IP packets across a serial interface, use the ppp bridge ip command in interface configuration mode. Use the no form of this command to disable IP packet half-bridging.
ppp bridge ip
no ppp bridge ip
Syntax Description
This command has no arguments or keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
When you configure a serial or ISDN interface for half-bridging, you configure it to function as a node on an Ethernet subnetwork. It communicates with a bridge on the subnetwork by sending and receiving bridge packets. The serial interface converts bridge packets to routed packets and forwards them, as needed.
The interface must be configured with an IP address for communication on the Ethernet subnetwork, and the IP address must be on the same subnetwork as the bridge.
You cannot configure a serial interface for both half-bridging and for transparent bridging.
No more than one half-bridge should be on any subnetwork.
Examples
The following example configures serial interface 0 for half-bridging of IP. The remote bridge and other Ethernet nodes must be on the same subnetwork.
interface serial 0ip address 172.69.5.8ppp bridge ipRelated Commands
ppp bridge ipx
To enable half-bridging of Internetwork Packet Exchange (IPX) packets across a serial interface, use the ppp bridge ipx command in interface configuration mode. Use the no form of this command to return to novell-ether encapsulation.
ppp bridge ipx [novell-ether | arpa | sap | snap]
no ppp bridge ipx
Syntax Description
Defaults
Default encapsulation is novell-ether.
Command Modes
Interface configuration
Command History
Usage Guidelines
When you configure a serial interface for half bridging, you configure it to function as a node on an Ethernet subnetwork. It communicates with a bridge on the subnetwork by sending and receiving bridge packets. The serial interface converts bridge packets to routed packets and forwards them, as needed.
The serial interface must be configured with an IPX address for communication on the Ethernet subnetwork, and the IPX address must be on the same subnetwork as the bridge.
You cannot configure a serial interface for both half-bridging and for transparent bridging.
No more than one half-bridge should be on any subnetwork.
Examples
The following example configures serial interface 0 for half-bridging of IPX. The remote bridge and other Ethernet nodes must be on the same subnetwork.
interface serial 0ppp bridge ipxipx network 1800Related Commands
ppp callback (DDR)
To enable a dialer interface that is not a data terminal ready (DTR) interface to function either as a callback client that requests callback or as a callback server that accepts callback requests, use the ppp callback command in interface configuration mode.
ppp callback {accept | permit | request}
no ppp callback
Syntax Description
Defaults
Callback requests are neither accepted nor requested.
Command Modes
Interface configuration
Command History
Usage Guidelines
An interface can request PPP callback only if the interface is configured for PPP authentication with Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP).
Examples
The following example configures a previously defined dialer interface to accept PPP callback requests:
ppp callback acceptRelated Commands
ppp callback (PPP client)
To enable a PPP client to dial in to an asynchronous interface and request a callback, use the ppp callback command in interface configuration mode. Use the no form of this command to disable callback acceptance.
ppp callback {accept | initiate}
no ppp callback
Syntax Description
accept
Accept callback requests from RFC1570-compliant PPP clients on the interface.
initiate
Initiate a callback to non-RFC1570-compliant PPP clients dialing in to an asynchronous interface.
Defaults
Callback requests are not accepted on asynchronous interfaces.
Command Modes
Interface configuration
Command History
Usage Guidelines
PPP callback can only be initiated if the interface is configured for authentication using CHAP or PAP.
Examples
The following example accepts a callback request from an RFC-compliant PPP client:
ppp callback acceptThe following example accepts a callback request from a non-RFC-compliant PPP client:
ppp callback initiateRelated Commands
ppp caller name
To set the caller option when no Calling Line Identification (CLID) is available, use the ppp caller name command in interface configuration mode. To remove the name, use the no form of this command.
ppp caller name name
no ppp caller name name
Syntax Description
Defaults
Command is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command sets the username used when the CLID is not available. This username is used only in the case where the ppp dnis command is configured and the CLID is not available.
Examples
The following example shows how to configure a call to user1:
interface Serial0:15description "PRI D channel"ip unnumbered Loopback0encapsulation pppno keepalivedialer pool-member 1 max-link 1isdn switch-type primary-net5isdn incoming-voice modemno fair-queueno cdp enableppp caller name user1ppp authentication pap chap callin USERS&TUNNELSppp chap hostname oshRelated Commands
ppp dnis
To configure a set of dialed number identification service (DNIS) numbers to check an incoming call against to automatically authenticate and authorize a user, use the ppp dnis command in interface configuration mode. To remove the numbers, use the no form of this command.
ppp dnis DNIS-numbers
no ppp dnis DNIS-numbers
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command enables a method of authenticating and authorizing a user based on the DNIS. The DNIS is the number dialed by the user. If the dialed number for this session matches one of the numbers configured in the ppp dnis command, the user is automatically authenticated and authorized for the session. Any other configured PPP authentication is not performed. In the case of DNIS authentication, the Calling Line Identification (CLID) is used as the username. If the CLID is unavailable, the username is the name configured with the ppp caller name command. If neither the CLID nor a caller name is configured, the username will automatically be set to "no-clid."
Examples
The following example shows how to set the DNIS for a call:
interface Serial0:15description "PRI D channel"ip unnumbered Loopback0encapsulation pppno keepalivedialer pool-member 1 max-link 1isdn switch-type primary-net5isdn incoming-voice modemno fair-queueno cdp enableppp dnis 13693 132ppp authentication pap chap callin USERS&TUNNELSppp chap hostname oshRelated Commands
ppp ipcp
To configure PPP IP Control Protocol (IPCP) features such as the ability to provide primary and secondary Domain Name Server (DNS) and Windows Internet Naming Service (WINS) server addresses, and the ability to accept any address requested by a peer and so on, use the ppp ipcp command in template or interface configuration mode. To disable a ppp ipcp feature, use the no form of this command.
ppp ipcp {accept-address} | {dns {reject | accept | primary-ip-address [secondary-ip-address] [accept]} | {ignore-map} | {username unique} | {wins {reject | accept | primary-ip-address [secondary-ip-address] [accept]}
no ppp ipcp {accept-address} | {dns [{reject | accept | primary-ip-address [secondary-ip-address] [accept]}] | {ignore-map} | {username unique} | {wins [{reject | accept | primary-ip-address [secondary-ip-address] [accept]}]
Syntax Description
Defaults
No servers are configured, and no address request is made.
Command Modes
Template or interface configuration
Command History
12.0(6)T
This command was introduced.
12.1(5)
The reject and accept keywords were added.
Usage Guidelines
To negate a command, the dns, wins, accept-address, ignore-map, and username unique keywords can be entered without addresses or other options. See the examples below for clarification.
Examples
The following examples show use of the ppp ipcp command:
ppp ipcp accept-addressppp ipcp dns 10.1.1.3ppp ipcp dns 10.1.1.3 10.1.1.4ppp ipcp dns 10.1.1.1 10.1.1.2 acceptppp ipcp dns acceptppp ipcp dns rejectppp ipcp ignore-mapppp ipcp username uniqueppp ipcp wins 10.1.1.1 10.1.1.2ppp ipcp wins acceptThe following examples show how to use the no form of the ppp ipcp command:
no ppp ipcp wins 10.1.1.1 10.1.1.2no ppp ipcp winsno ppp ipcp ignore-mapRelated Commands
ppp iphc max-header
To set the maximum size of the largest IP header that may be compressed when configuring Internet Protocol Header Compression (IPHC) control options over PPP, use the ppp iphc max-header command in interface configuration mode. To change the configuration, use the no form of this command.
ppp iphc max-header bytes
no ppp iphc max-header bytes
Syntax Description
bytes
Maximum size, in bytes, of the largest IP header that may be compressed. The range is from 60 to 168 bytes, and the default is 168 bytes.
Defaults
168 bytes
Command Modes
Interface configuration
Command History
Usage Guidelines
There are two types of IP header compression used over PPP: Van Jacobsen header compression defined in RFC 1332 and enabled with the ip tcp header-compression command, and IPHC defined in RFC 2509 and enabled with the ip rtp header-compression command. The ppp iphc set of commands controls parameters that pertain to the form of IPHC described in RFC 2509.
The IPHC specification allows low speed links to run more efficiently by reducing the size of the IP headers as transmitted on the link. IPHC supports compressed Real-Time Transport Protocol (cRTP), compressed User Datagram Protocol (cUDP), and compressed Transaction Control Protocol (cTCP).
An IPHC-enabled interface sends only changes to the header instead of sending the entire header with every packet. At the beginning of a transmission, the transmitting end (the compressor) sends a full header packet to the receiving end (the decompressor). After the initial packet is sent, the compressor sends all other packets with headers that contain only the differences between them and the original full header. The decompressor maintains a copy of the original full header and reconstructs all the other packet headers by adding the changes to them.
The header data that is different with each packet is referred to as the session state, and is identified by a session ID or connection ID.
When the decompressor receives a compressed packet, it reconstructs the packet header by adding the difference to the saved uncompressed header. Typically, IPHC enables the header to be compressed to two bytes (four bytes if UDP checksums are used).
The following fields in a packet header usually remain the same throughout a transmission:
•
•
•
The following fields in a packet header usually change during a transmission:
•
•
•
•
•
Examples
The following example shows how to change the maximum size of the largest IP header that may be compressed from the default of 168 bytes to 114 bytes:
interface Multilink1ip address 10.100.253.1 255.255.255.0no ip directed-broadcastno ip route-cacheip tcp header-compression iphc-formatno ip mroute-cachefair-queue 64 256 1000no cdp enableppp multilinkppp multilink fragment-delay 20ppp multilink interleavemultilink-group 1ip rtp header-compression iphc-formatip rtp priority 16384 50 64ppp iphc max-header 114ppp iphc max-time 10ppp iphc max-period 512Related Commands
ppp iphc max-period
To set the maximum number of compressed packets that can be sent before a full header when configuring Internet Protocol Header Compression (IPHC) control options over PPP, use the ppp iphc max-period command in interface configuration mode. To change the configuration, use the no form of this command.
ppp iphc max-period packets
no ppp iphc max-period packets
Syntax Description
packets
Maximum number of compressed packets that can be sent before a full header. The range is from 1 to 65,535 packets, and the default is 256 packets.
Defaults
256 packets
Command Modes
Interface configuration
Command History
Usage Guidelines
There are two types of IP header compression used over PPP: Van Jacobsen header compression, which is defined in RFC 1332, and a newer compression type described in RFC 2509. The ppp iphc set of commands controls parameters that pertain to the form of IPHC described in RFC 2509.
The IPHC specification allows low speed links to run more efficiently when IP headers are extremely large. IPHC supports compressed Real-Time Transport Protocol (cRTP), compressed User Datagram Protocol (cUDP), and compressed Transaction Control Protocol (cTCP).
An IPHC-enabled interface sends only changes to the header instead of sending the entire header with every packet. At the beginning of a transmission, the transmitting end (the compressor) sends a full header packet to the receiving end (the decompressor). After the initial packet is sent, the compressor sends all other packets with headers that contain only the differences between them and the original full header. The decompressor maintains a copy of the original full header and reconstructs all the other packet headers by adding the changes to them.
The header data that is different with each packet is referred to as the session state, and is identified by a session ID or connection ID.
When the decompressor receives a compressed packet, it reconstructs the packet header by adding the difference to the saved uncompressed header. Typically, IPHC enables the header to be compressed to two bytes (four bytes if UDP checksums are used).
The following fields in a packet header usually remain the same throughout a transmission:
•
•
•
The following fields in a packet header usually change during a transmission:
•
•
•
•
•
The ppp iphc max-period command is specifically related to an IPHC frame format known as compressed_non_TCP. The recovery of lost compressed_non_TCP frames on lossy links is much improved by allowing more full headers to flow and by configuring less compression.
Examples
The following example shows how to increase the maximum number of compressed packets that can be sent before a full header from 256 to 512 packets when configuring IPHC control options over PPP:
interface Multilink1ip address 10.100.253.1 255.255.255.0no ip directed-broadcastno ip route-cacheip tcp header-compression iphc-formatno ip mroute-cachefair-queue 64 256 1000no cdp enableppp multilinkppp multilink fragment-delay 20ppp multilink interleavemultilink-group 1ip rtp header-compression iphc-formatip rtp priority 16384 50 64ppp iphc max-header 114ppp iphc max-time 10ppp iphc max-period 512Related Commands
ppp iphc max-time
To set the maximum time allowed between full headers when configuring Internet Protocol Header Compression (IPHC) control options over PPP, use the ppp iphc max-time command in interface configuration mode. To change the configuration, use the no form of this command.
ppp iphc max-time seconds
no ppp iphc max-time seconds
Syntax Description
seconds
Maximum time, in seconds, allowed between full headers. The range is from 1 to 255 seconds, and the default is 5 seconds.
Defaults
5 seconds
Command Modes
Interface configuration
Command History
Usage Guidelines
There are two forms of IP header compression used over PPP: Van Jacobsen header compression, which is defined in RFC 1332, and a newer form of compression described in RFC 2509. The ppp iphc set of commands controls parameters that pertain to the form of IPHC described in RFC 2509.
The IPHC specification allows low speed links to run more efficiently by reducing the size of IP headers as transmitted on the link. IPHC supports compressed Real-Time Transport Protocol (cRTP), compressed User Datagram Protocol (cUDP), and compressed Transaction Control Protocol (cTCP).
An IPHC-enabled interface sends only changes to the header instead of sending the entire header with every packet. At the beginning of a transmission, the transmitting end (the compressor) sends a full header packet to the receiving end (the decompressor). After the initial packet is sent, the compressor sends all other packets with headers that contain only the differences between them and the original full header. The decompressor maintains a copy of the original full header and reconstructs all the other packet headers by adding the changes to them.
The header data that is different with each packet is referred to as the session state, and is identified by a session ID or connection ID.
When the decompressor receives a compressed packet, it reconstructs the packet header by adding the difference to the saved uncompressed header. Typically, IPHC enables the header to be compressed to two bytes (four bytes if UDP checksums are used).
The following fields in a packet header usually remain the same throughout a transmission:
•
•
•
The following fields in a packet header usually change during a transmission:
•
•
•
•
•
The ppp iphc max-time command is specifically related to an IPHC frame format known as compressed_non_TCP. The recovery of lost compressed_non_TCP frames on lossy links is much improved by allowing more full headers to flow and by configuring less compression.
Examples
The following example shows how to change the number of compressed packets that can be sent before a full header from the default 5 seconds to 10 seconds:
interface Multilink1ip address 10.100.253.1 255.255.255.0no ip directed-broadcastno ip route-cacheip tcp header-compression iphc-formatno ip mroute-cachefair-queue 64 256 1000no cdp enableppp multilinkppp multilink fragment-delay 20ppp multilink interleavemultilink-group 1ip rtp header-compression iphc-formatip rtp priority 16384 50 64ppp iphc max-header 114ppp iphc max-time 10ppp iphc max-period 512Related Commands
ppp lcp fast-start
To allow a Point-to-Point (PPP) interface to respond immediately to incoming packets once a connection is established, use the ppp lcp fast-start interface configuration command. To specify that PPP delay before responding, use the no form of this command.
ppp lcp fast-start
no ppp lcp fast-start
Syntax Description
This command has no arguments or keywords.
Defaults
Default is enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Some systems, typically those with external modems, may have problems with slow or electrically noisy hardware. If the no ppp lcp fast-start command is specified, PPP starts a debounce timer and waits for it to expire before attempting to communicate with the peer system, thereby reducing the probability of a false start on the interface.
If the no ppp lcp fast-start command is not specified, PPP will not use a debounce timer and will respond immediately to incoming packets once a connection is made.
The default fast-start enabled state should not be disabled unless there is a problem with slow or electronically noisy hardware. This setting prevents PPP from waiting for a debounce timer to expire before responding to inbound frames.
Examples
The following example disables fast start:
no ppp lcp fast-startppp loopback ignore
To disable PPP loopback detection, use the ppp loopback ignore command in interface configuration mode. To reenable PPP loopback detection (the default condition), use the no form of this command.
ppp loopback ignore
no ppp loopback ignore
Syntax Description
This command has no arguments or keywords.
Defaults
Loopback detection is enabled.
Command Modes
Interface configuration
Command History
11.3
This command was introduced as ppp ignore-loopback.
12.2(5)T
The ppp loopback ignore command replaced the ppp ignore-loopback command.
Usage Guidelines
A circuit loopback normally indicates faulty external switching equipment or wiring errors. The PPP protocol includes a mechanism that detects when a circuit is looped back, that is, when the circuit is fed back upon itself such that the router is reading its own output on that link. A first phase of loopback detection occurs during Link Control Protocol (LCP) negotiation when the circuit is being established. A loopback condition that occurs after the connection is made (after LCP negotiation) can be detected if link keepalives are enabled. If keepalives are disabled on the link, the second phase of loopback detection is not available.
The normal operation (default) is for PPP to check for a loopback condition and terminate the connection when a loopback is detected. There are, however, some situations where it is necessary to disable loopback detection, such as during certain testing situations, or when software detects problematic peers that do not implement the PPP protocol correctly. The ppp loopback ignore command disables normal operation; the no ppp loopback ignore command restores normal operation.
Note
Examples
The following example shows PPP loopback detection being disabled:
interface Serial0:15description "PRI D channel"ip unnumbered Loopback0encapsulation pppppp loopback ignoreRelated Commands
keepalive
Configures a keepalive packet that is sent at a certain time interval, and for a certain number of retries if there is no response, to keep an interface active.
ppp max-bad-auth
To configure a point-to-point interface not to reset itself immediately after an authentication failure but instead to allow a specified number of authentication retries, use the ppp max-bad-auth command in interface configuration mode. Use the no form of this command to reset to the default of immediate reset.
ppp max-bad-auth number
no ppp max-bad-auth
Syntax Description
Defaults
Default is 0.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies to any serial interface (asynchronous serial, synchronous serial, or ISDN) on which PPP encapsulation is enabled.
Examples
The following example sets BRI interface 0 to allow two additional retries after an initial authentication failure (for a total of three failed authentication attempts):
interface bri 0encapsulation pppppp authentication chapppp max-bad-auth 3Related Commands
ppp ms-chap refuse
To refuse Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) authentication from peers requesting it, use the ppp ms-chap refuse command in interface configuration mode. To allow MS-CHAP authentication, use the no form of this command.
ppp ms-chap refuse [callin]
no ppp ms-chap refuse [callin]
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command specifies that MS-CHAP authentication is disabled for all calls, meaning that all attempts by the peer to force the user to authenticate using MS-CHAP will be refused. If the callin keyword is used, MS-CHAP authentication is disabled for incoming calls from the peer, but will still be performed on outgoing calls to the peer.
If outbound Password Authentication Protocol (PAP) has been enabled (using the ppp pap sent-username command), PAP will be suggested as the authentication method in the refusal packet.
Examples
The following example shows how to disable MS-CHAP authentication if a peer calls in requesting MS-CHAP authentication. The method of encapsulation on interface ISDN BRI number 0 is PPP.
interface bri 0encapsulation pppppp ms-chap refuseRelated Commands
ppp ms-chap-v2 refuse
To refuse Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) version 2 authentication from peers requesting it, use the ppp ms-chap-v2 refuse command in interface configuration mode. To allow MS-CHAP version 2 authentication, use the no form of this command.
ppp ms-chap-v2 refuse [callin]
no ppp ms-chap-v2 refuse [callin]
Syntax Description
Defaults
This command is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command specifies that MS-CHAP version 2 authentication is disabled for all calls, meaning that all attempts by the peer to force the user to authenticate using MS-CHAP version 2 will be refused. If the callin keyword is used, MS-CHAP version 2 authentication is disabled for incoming calls from the peer, but will still be performed on outgoing calls to the peer.
If outbound Password Authentication Protocol (PAP) has been enabled (using the ppp pap sent-username command), PAP will be suggested as the authentication method in the refusal packet.
Examples
The following example shows how to disable MS-CHAP version 2 authentication if a peer calls in requesting MS-CHAP version 2 authentication. The method of encapsulation on interface ISDN BRI number 0 is PPP.
interface bri 0encapsulation pppppp ms-chap-v2 refuseRelated Commands
ppp multilink
To enable Multilink PPP (MLP) on an interface and, optionally, to enable dynamic bandwidth allocation, use the ppp multilink command in interface configuration mode. Use the no form of this command to disable Multilink PPP or, optionally, to disable only dynamic bandwidth allocation.
ppp multilink [bap]
no ppp multilink [bap [required]]
Syntax Description
Defaults
Disabled. When BACP is enabled, the defaults are to accept calls and to set the timeout pending at 30 seconds.
Command Modes
Interface configuration
Command History
Usage Guidelines
This command applies only to interfaces that use PPP encapsulation.
MLP and PPP reliable links do not work together.
PPP compression is allowed with MLP.
MLP is designed to work over single or multiple interfaces that are configured to support both dial-on-demand rotary groups and PPP encapsulation. This command applies synchronous serial interfaces, asynchronous serial interfaces, ISDN BRIs, and ISDN PRIs.
When using the ppp multilink command, the first channel will negotiate the appropriate Network Control Protocol (NCP) layers (such as the IP Control Protocol and IPX Control Protocol), but subsequent links will negotiate only the link control protocol and MLP. NCP layers do not get negotiated on these links, and it is normal to see these layers in a closed state.
This command with the bap keyword must be used before configuring any ppp bap commands and options. If the bap required option is configured and a reject of the options is received, the multilink bundle is torn down.
The no form of the command without the bap keyword disables both MLP and BACP on the interface.
When BACP negotiation is enabled by this command, the following values are used during negotiations to identify the protocols:
The dialer load-threshold command is used to enable a rotary group to bring up additional links and to add them to a multilink bundle.
When MLP is configured, the dialer-load threshold 1 command no longer keeps a multilink bundle of any number of links connected indefinitely and the dialer-load threshold 2 command no longer keeps a multilink bundle of 2 links connected indefinitely. If you want a multilink bundle to be connected indefinitely, you must set a very high idle timer.
Examples
The following partial example configures a dialer for Multilink PPP; it does not show the configuration of the physical interfaces.
interface Dialer0ip address 99.0.0.2 255.0.0.0encapsulation pppdialer in-banddialer idle-timeout 500dialer map ip 99.0.0.1 name atlanta broadcast 81012345678901dialer load-threshold 30 eitherdialer-group 1ppp authentication chapppp multilinkRelated Commands
ppp multilink fragmentation
To enable packet fragmentation, use the ppp multilink fragmentation interface configuration command. To disable fragmentation, use the no form of this command.
ppp multilink fragmentation
no ppp multilink fragmentation
Syntax Description
This command has no arguments or keywords.
Defaults
Fragmentation is enabled.
Command Modes
Interface configuration
Command History
Usage Guidelines
Disable multilink fragmentation using the no ppp multilink fragmentation command if fragmentation causes performance degradation. Performance degradation due to multilink fragmentation has sometimes been observed with asynchronous member links.
Examples
The following example disables packet fragmentation:
no ppp multilink fragmentationRelated Commands
ppp multilink fragment-delay
Specifies a maximum size, in units of time, for packet fragments on an MLP bundle.
ppp multilink interleave
Enables MLP interleaving.
ppp multilink fragment-delay
To configure a maximum delay allowed for transmission of a packet fragment on a Multilink PPP (MLP) bundle, use the ppp multilink fragment-delay command in interface configuration mode. Use the no form of the command to reset the maximum delay to the default value.
ppp multilink fragment-delay milliseconds
no ppp multilink fragment-delay
Syntax Description
milliseconds
Maximum delay, in milliseconds, allowed for any packet fragment. Default is 30 milliseconds.
Defaults
Disabled. Default delay is 30 milliseconds.
Command Modes
Interface configuration
Command History
Usage Guidelines
The ppp multilink fragment-delay command applies only to interfaces that can configure a bundle interface. These include virtual-templates, dialer interfaces, and ISDN BRI or PRI interfaces.
Multilink PPP chooses a fragment size based on the maximum delay allowed. If real-time traffic requires a certain maximum bound on delay, using this command to set that maximum delay can ensure that a real-time packet will get interleaved within the fragments of a large packet.
Examples
The following example requires a voice to have a maximum bound on delay of 20 milliseconds:
ppp multilink fragment-delay 20Related Commands
ppp multilink idle-link
To configure the Multilink PPP (MLP) bundle so that the first link member enters into "receive-only" mode when an additional B channel is added, use the ppp multilink idle-link command in interface configuration mode. Use the no form of this command to remove this functionality.
ppp multilink idle-link
no ppp multilink idle-link
Syntax Description
This command has no arguments or keywords.
Defaults
Multilink idle-link is not set.
Command Modes
Interface configuration
Command History
Usage Guidelines
Use this command to ensure that the primary link in the AO/DI bundle enters "receive-only" mode as soon as the first additional B channel is added to the bundle. Additional member links are added to the Multilink PPP bundle in order to increase traffic throughput and are disconnected once the traffic load is reduced. During this timeframe, the X.25 SVC remains active. The dialer load-threshold value determines the traffic threshold limits for the bundle.
Examples
The following example configures the interface (dialer interface 1) to add additional links to the MLP bundle once the traffic load on the primary link is reached:
interface dialer1ppp multilink idle-linkppp multilink interleave
To enable interleaving of Real-Time Transport Protocol (RTP) packets among the fragments of larger packets on a Multilink PPP (MLP) bundle, use the ppp multilink interleave command in interface configuration mode. Use the no form of the command to disable interleaving.
ppp multilink interleave
no ppp multilink interleave
Syntax Description
This command has no arguments and keywords.
Defaults
This function is disabled by default.
Command Modes
Interface configuration
Command History
Usage Guidelines
The ppp multilink interleave command applies only to interfaces that can configure a bundle interface. These include virtual-templates, dialer interfaces, and ISDN BRI or PRI interfaces.
Examples
The following example defines a virtual interface template that enables Multilink PPP interleaving and a maximum real-time traffic delay of 20 milliseconds, and then applies that virtual template to the Multilink PPP bundle:
interface virtual-template 1ip unnumbered ethernet 0ppp multilinkppp multilink interleaveppp multilink fragment-delay 20!multilink virtual-template 1Related Commands
ppp quality
To enable Link Quality Monitoring (LQM) on a serial interface, use the ppp quality command in interface configuration mode. Use the no form of this command to disable LQM.
ppp quality percentage
no ppp quality
Syntax Description
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
The percentages are calculated for both incoming and outgoing directions. The outgoing quality is calculated by comparing the total number of packets and bytes sent to the total number of packets and bytes received by the destination node. The incoming quality is calculated by comparing the total number of packets and bytes received to the total number of packets and bytes sent by the destination node.
If the link quality percentage is not maintained, the link is deemed to be of poor quality and is taken down. LQM implements a time lag so that the link does not bounce up and down.
Examples
The following example enables LQM on serial interface 2:
interface serial 2encapsulation pppppp quality 80Related Commands
exec
Allows an EXEC process on a line.
keepalive
Sets the keepalive timer for a specific interface.
ppp reliable-link
To enable Link Access Procedure, Balanced (LAPB) Numbered Mode negotiation for a reliable serial link, use the ppp reliable-link command in interface configuration mode. Use the no form of the command to disable negotiation for a PPP reliable link on a specified interface.
ppp reliable-link
no ppp reliable-link
Syntax Description
This command has no arguments and keywords.
Defaults
Disabled
Command Modes
Interface configuration
Command History
Usage Guidelines
Enabling LAPB Numbered Mode negotiation as a means of providing a reliable link does not guarantee that all connections through the specified interface will in fact use reliable link. It only guarantees that the router will attempt to negotiate reliable link on this interface.
PPP reliable link can be used with PPP compression over the link, but it does not require PPP compression.
PPP reliable link does not work with Multilink PPP.
You can use the show interface command to determine whether LAPB has been established on the link. You can troubleshoot PPP reliable link by using the debug lapb command and the debug ppp negotiations, debug ppp errors, and debug ppp packets commands.
Examples
The following example enables PPP reliable link and predictor compression on interface BRI 0:
interface bri 0description Enables predictor compression on BRI 0ip address 170.1.1.1 255.255.255.0encapsulation pppdialer map ip 170.1.1.2 name starbuck 14195291357compress predictorppp authentication chapdialer-group 1ppp reliable-linkRelated Commands
