5.5 Static and Default Routing
5.5.7 Using an extended access list to define a dialer list
Figure shows a more complex topology set up with DDR. This topology is used for the extended configuration in which you see how you can combine the commands described earlier for DDR to set up an extended access list to trigger an ISDN call. You may use many of the same commands for configuring a simple ISDN call. Access lists can be applied to a dialer group to trigger dialing, and then you can apply that dialer list to the interface. Table describes the commands used in the configuration.

Note: Click on the topology to view router configurations.

DDR is configured on router Cisco-a to connect with Cisco-b or Cisco-c for all IP traffic except Telnet and FTP. The details about what is interesting to DDR are defined in an access list.

The service provider provides other details that you must use when you configure your router for ISDN.

Configuring ISDN by using extended access lists is more common in networks than configuring ISDN by using a dialer list and dialer map statement, as is shown in the previous configuration example.