PPP Commands
8-84 Configuring the Point-to-Point Protocol

encapsulation ppp

ThiscommandsetsthePointtoPointProtocol(PPP)astheencapsulationmethodusedbyaserial
port.TousePPPencapsulation,theXSRmustbeconfiguredwithanIProutingprotocol.
Syntax
encapsulation ppp
Syntax of the “no” Form
no encapsulation ppp
Default
Noencapsulation
Mode
Interfaceconfiguration:XSR(config-if<xx>)
Example
ThefollowingexampleenablesPPPencapsulationonSerialinterface1/0:
XSR(config)#interface serial 1/0
XSR(config-if<S1/0>)#encapsulation ppp

interface

Thiscommandselectsaphysicalorvirtualportforconfigurationasarouterinterface.TheXSR
supportsATM,BRI,Dialer,Fast/GigabitEthernet,Loopback,Multilink,Serial,orVPNinterfaces.
Forconfigurationpurposes,allserialportsandT1/E1/ISDNPRIchannelgroupsaretreatedasa
serialinterface.
Optionally,youcansetuptheConsoleportontheXSR1800seriesasaWANinterfacefordial
backuppurposes(refertotheCautionbelow).Dosobyentering0only.
Note: If encapsulation is changed from one type to another, all related values of the current
encapsulation and any sub-interface settings are deleted. Also, once encapsulation is set on an
interface, any sub-interface of that port created later is automatically encapsulated. Finally, you must
first enter the no encapsulation command to change the encapsulation type.
Caution: Be aware that when you enable the Console port as a WAN port, you can no longer
directly connect to it because it is in data communication mode. Your only access to the CLI will be
to Telnet to an IP address of a configured port. Also, if your startup-config file does not configure
any ports properly and sets up the console port as a serial interface, you will no longer be able to
login and will have to press the Default button to erase your configuration. For details about
configuring the Console with a modem, see “Chapter 2: Managing the XSR in the XSR User’s
Guide.