Specifications

Overview of Dial Interfaces, Controllers, and Lines
Logical Interfaces
DC-6
Cisco IOS Dial Technologies Configuration Guide
Templates for Virtual Access Interfaces
Virtual templates project configuration information to temporary virtual access interfaces triggered by
multilink or virtual private dial-up network (VPDN) session events. When a virtual access interface is
triggered, the configuration attributes in the virtual template are cloned and the negotiated parameters
are applied to the connection.
The following example shows a virtual template interface on a Cisco 7206 router, which is used as a
home gateway in a VPDN scenario:
Router# configure terminal
Router(config)# interface virtual-template 1
Router(config-if)# ip unnumbered ethernet 2/1
Router(config-if)# peer default ip address pool cisco-pool
Router(config-if)# ppp authentication chap pap
Router(config-if)# exit
Router(config)# vpdn enable
Router(config)# vpdn incoming isp cisco.com virtual-template 1
Templates for Protocol Translation
Virtual templates are used to simplify the process of configuring protocol translation to tunnel PPP or
Serial Line Internet Protocol (SLIP) across X.25, TCP, and LAT networks. You can create a virtual
interface template using the interface virtual-template command, and you can use it for one-step and
two-step protocol translation. When a user dials in through a vty line and a tunnel connection is
established, the router clones the attributes of the virtual interface template onto a virtual access
interface. This virtual access interface is a temporary interface that supports the protocol configuration
specified in the virtual interface template. This virtual access interface is created dynamically and lasts
only as long as the tunnel session is active.
The virtual template in the following example explicitly specifies PPP encapsulation. The translation is
from X.25 to PPP, which enables tunneling of PPP across an X.25 network.
Router# configure terminal
Router(config)# interface virtual-template 1
Router(config-if)# ip unnumbered ethernet 0
Router(config-if)# peer default ip address 172.18.2.131
Router(config-if)# encapsulation ppp
Router(config-if)# exit
Router(config)# translate x25 5555678 virtual-template 1
For more information, refer to the chapter “Configuring Protocol Translation and Virtual Asynchronous
Devices” in the Cisco IOS Terminal Services Configuration Guide.
Logical Interfaces
A logical interface receives and sends data packets and controls physical interfaces. Cisco IOS software
provides three logical interfaces used for dial access. These interfaces are described in the following
sections:
• Dialer Interfaces
• Virtual Access Interfaces
• Virtual Asynchronous Interfaces