- Enterasys Security Router User's Guide

Configuring PPP with a Dialed Backup Line
8-10 Configuring PPP
Configuring PPP with a Dialed Backup Line
You can configure PPP on the following types of physical interfaces:
• Asynchronous serial
•Synchronous serial
•T1/E1
By enabling PPP encapsulation on physical interfaces, PPP can also be used on calls placed by the
dialer interfaces that use the physical interfaces. Refer to Figure 8-6 for an example of an XSR
configured with one backup dial line to two different sites.
Figure 8-6 XSR Configuration with One Backup Dial Line to Different Sites
Configuring a Synchronous Serial Interface
Perform the following steps to configure a synchronous V.35 serial interface to communicate with
PPP:
1. Enter interface serial <card/port> to specify the interface.
XSR(config)#interface serial 1/0
2. Enter the media-type for the interface (default: RS232).
XSR(config-if<S1/0>)#media-type v35
3. Enter encapsulation ppp to enable PPP encapsulation.
XSR(config-if<S1/0>)#encapsulation ppp
4. Set the local IP address of this interface.
XSR(config-if<S1/0>)#ip address 192.168.1.1 255.255.255.0
Site B
Central Site
XSR
Primary link
Serial interface 1/1
Backup link
Primary link
Serial interface 1/0
PSTN