Using Multilink PPP over Dialer Interface Links

The dialer profiles implementation of dial-on-demand routing (DDR) is based on a separation between logical and physical interface configuration. Dialer profiles also allow the logical and physical configurations to be bound together dynamically on a per-call basis.

Dialer profiles are advantageous in the following situations:

• When you want to share an interface (ISDN, asynchronous, or synchronous serial) to place or receive calls.
• When you want to change any configuration on a per-user basis.
• When you want to maximize ISDN channel usage using the Dynamic Multiple Encapsulations feature to configure various encapsulation types and per-user configurations on the same ISDN B channel at different times according to the type of call.
• When you want to bridge to many destinations, and for avoiding split horizon problems.

Most routed protocols are supported; however, International Organization for Standardization Connectionless Network Service (ISO CLNS) is not supported.

If you decide to configure dialer profiles, you must disable validation of source addresses for the routed protocols you support.

Before using Multilink PPP over dialer interface links, a traffic policy (also known as a policy map) must be created. (See the "Prerequisites" section on page 3 .) Policy maps are created using the Modular Quality of Service (QoS) Command-Line Interface (CLI) (MQC).

The MQC is a CLI structure that allows users to create traffic policies (policy maps) and attach these policy maps to interfaces. A policy map contains a traffic class and one or more QoS features. A traffic class is used to classify traffic. The QoS features in the traffic policy determine how to treat the classified traffic.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface dialer dialer-rotary-group-number

4.    ip address ip-address mask [secondary]

5.    ip unnumbered type number

6.    encapsulation encapsulation-type

7.    dialer pool number

8.    dialer in-band [no-parity | odd-parity]

9.    service-policy output policy-map-name

10.    service-policy input policy-map-name

11.    ppp authentication {protocol1 [protocol2...]} [if-needed] [list-name | default] [callin] [one-time] [optional]

12.    ppp chap hostname hostname

13.    ppp chap password secret

14.    ppp multilink [bap]

15.    ppp multilink fragment delay milliseconds [microseconds]

16.    ppp multilink interleave

17.    end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface dialer dialer-rotary-group-number Example: Router(config)# interface dialer 1	Defines a dialer rotary group and enters interface configuration mode. Enter the dialer rotary group number.
Step 4	ip address ip-address mask [secondary] Example: Router(config-if)# ip address 10.10.100.1 255.255.255.0	Sets a primary IP address for an interface. This command can also set the optional secondary IP address for an interface. Enter the primary IP address (and, optionally, the secondary IP address).
Step 5	ip unnumbered type number Example: Router(config-if)# ip unnumbered ethernet 0	(Optional) Enables IP processing on a serial interface without assigning an explicit IP address to the interface. Enter the type and number of another interface on which the router has an assigned IP address. It cannot be another unnumbered interface.
Step 6	encapsulation encapsulation-type Example: Router(config-if)# encapsulation ppp	Sets the encapsulation method used by the interface. Enter the encapsulation method. For this feature, enter ppp.
Step 7	dialer pool number Example: Router(config-if)# dialer pool 3	(Optional) Specifies which dialing pool to use to connect to a specific destination subnetwork. Enter the dialing pool number.
Step 8	dialer in-band [no-parity | odd-parity] Example: Router(config-if)# dialer in-band	(Optional) Specifies that dial-on-demand routing (DDR) is to be supported.
Step 9	service-policy output policy-map-name Example: Router(config-if)# service-policy output policy1	Attaches the previously created QoS traffic policy (policy map). The policy map evaluates and applies QoS features for traffic leaving the interface. Enter the policy map name.
Step 10	service-policy input policy-map-name Example: Router(config-if)# service-policy input policy1	Attaches the previously created QoS traffic policy (policy map). See the "Prerequisites" section on page 3 . The policy map evaluates and applies QoS features for traffic enteringthe interface. Enter the policy map name.
Step 11	ppp authentication {protocol1 [protocol2...]} [if-needed] [list-name | default] [callin] [one-time] [optional] Example: Router(config-if)# ppp authentication chap	Enables at least one Point-to-Point Protocol (PPP) authentication protocol and specifies the order in which the protocols are selected on the interface. Enter the PPP authentication protocol to be used.
Step 12	ppp chap hostname hostname Example: Router(config-if)# ppp chap hostname ISPCorp	Creates a pool of dialup routers that all appear to be the same host when authenticating with Challenge Handshake Authentication Protocol (CHAP). Enter the name sent in the CHAP challenge.
Step 13	ppp chap password secret Example: Router(config-if)# ppp chap password 7	Enables a router calling a collection of routers that do not support this command (such as routers running older Cisco IOS software images) to configure a CHAP secret password to use in response to challenges from an unknown peer. Enter the secret password used to compute the response value for any CHAP challenge from an unknown peer.
Step 14	ppp multilink [bap] Example: Router(config-if)# ppp multilink	Enables multilink on an interface.
Step 15	ppp multilink fragment delay milliseconds [microseconds] Example: Router(config-if)# ppp multilink fragment delay 20	Specifies a maximum size in units of time for packet fragments on a Multilink PPP (MLP) bundle. Enter the maximum amount of time, in milliseconds.
Step 16	ppp multilink interleave Example: Router(config-if)# ppp multilink interleave	Enables interleaving of packets among the fragments of larger packets on a multilink bundle.
Step 17	end Example: Router(config-if)# end	(Optional) Exits interface configuration mode.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface bri number

4.    dialer pool-member number [priority priority] [min-link minimum] [max-link maximum]

5.    dialer rotary-group interface-number

6.    ppp multilink [bap]

7.    end

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	interface bri number Example: Router(config)# interface bri 1	Configures a BRI interface and enters interface configuration mode. Enter port, connector, or interface card number.
Step 4	dialer pool-member number [priority priority] [min-link minimum] [max-link maximum] Example: Router(config-if)# dialer pool-member 3	(Optional) Configures a physical interface to be a member of a dialer profile dialing pool. Enter the dialer profile dialing pool number.
Step 5	dialer rotary-group interface-number Example: Router(config-if)# dialer rotary-group 1	(Optional) Includes a specified interface in a dialer rotary group. Enter the number of the dialer interface (defined in Step 4 ) in whose rotary group this interface is to be included.
Step 6	ppp multilink [bap] Example: Router(config-if)# ppp multilink	Enables Multilink on an interface.
Step 7	end Example: Router(config-if)# end	(Optional) Exits interface configuration mode.

SUMMARY STEPS

1.    enable

2.    show interfaces [type number] [first] [last] [accounting]

3.    show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]]

4.    exit

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. Enter your password if prompted.
Step 2	show interfaces [type number] [first] [last] [accounting] Example: Router# show interfaces	(Optional) Displays statistics for all interfaces configured on the router or access server.
Step 3	show ppp multilink [active | inactive | interface bundle-interface | [username name] [endpoint endpoint]] Example: Router# show ppp multilink	(Optional) Displays bundle information for the multilink bundles.
Step 4	exit Example: Router# exit	(Optional) Exits privileged EXEC mode.