# Configuration Tasks

The following procedure is an example of a PPP configuration on a serial interface. These steps are mandatory unless otherwise noted.

1. From Global Configuration mode, specify the physical interface on which you want to configure PPP.
   host1(config)#interface serial 3/0:2/5
2. Specify PPP as the encapsulation method (data-link protocol) on the interface.
   host1(config-if)#encapsulation ppp
3. Assign an IP address and subnet mask for the interface.
   host1(config-if)#ip address 192.168.22.10 255.255.255.0
4. Verify that your configuration changes are correct.
   host1#show ppp interface serial 3/0:2/5 config

encapsulation ppp

- Use to configure PPP as the encapsulation method.
- Example
  host1(config-if)#encapsulation ppp
- Use the no version to disable PPP on an interface.
- See encapsulation ppp.

interface atm

- Use to specify a previously configured ATM interface on which you want to configure PPP.
- To specify an ATM interface for ERX7xx models, ERX14xx models, and ERX310 router, use the slot/port.[subinterface ] format.
  - slot—Number of the chassis slot
  - port—Port number on the I/O module
  - subinterface—Number of the subinterface in the range 1–2147483647
- To specify an ATM interface for E120 and E320 routers, use the slot/adapter/port[.subinterface ] format.
  - slot—Number of the chassis slot
  - adapter—Identifier for the IOA within the E320 chassis, either 0 or 1, where:
    - 0 indicates that the IOA is installed in the right IOA bay (E120 router) or the upper IOA bay (E320 router).
    - 1 indicates that the IOA is installed in the left IOA bay (E120 router) or the lower IOA bay (E320 router).
  - port—Port number on the IOA
  - subinterface—Number of the subinterface in the range 1–2147483647
- For more information, see Creating a Basic Configuration in Configuring ATM .
- Examples
  host1(config-if)#interface atm 9/1.1 host1(config-if)#interface atm 5/0/1.1
- Use the no version to disable or remove the subinterface or the logical interface.
- See interface atm.

interface pos

- Use to specify a previously configured packet over SONET (POS) interface on which you want to configure PPP.
- To specify a POS interface for ERX7xx models, ERX14xx models, and ERX310 router, use the slot/port.[subinterface ] format.
  - slot—Number of the chassis slot
  - port—Port number on the I/O module
  - subinterface—Number of the subinterface
- To specify a POS interface for E120 and E320 routers, use the slot/adapter/port format.
  - slot—Number of the chassis slot
  - adapter—Identifier for the IOA within the E320 chassis, either 0 or 1, where:
    - 0 indicates that the IOA is installed in the right IOA bay (E120 router) or the upper IOA bay (E320 router).
    - 1 indicates that the IOA is installed in the left IOA bay (E120 router) or the lower IOA bay (E320 router).
  - port—Port number on the IOA
- For more information about modules that support POS interfaces, see chapter Configuring Unchannelized OCx/STMx Interfaces in JunosE Physical Layer Configuration Guide.
- Examples
  host1(config-if)#interface pos 0/1 host1(config-if)#interface pos 5/0/0
- Use the no version to remove the POS interface.
- See interface pos.

interface serial

- Use to specify a serial interface in the slot/port:channel/subchannel format by selecting a previously configured physical interface on which you want to configure PPP.
  - slot—Refers to a router chassis slot.
  - port—Refers to a CT3, T3, or E3 module I/O port.
  - channel—Refers to a T1 (DS1) channel.
  - subchannel—Represents a set of DS0 subchannels.
- Example
  host1(config)#interface serial 3/0:2/5
- Use the no version to disable or remove the subinterface or the logical interface.
- See interface serial.

ip address

- Use to assign an IP address and subnet mask for a PPP interface.
- Example
  host1(config-if)#ip address 192.168.22.10 255.255.255.0
- Use the no version to remove an IP address or disable IP processing.
- See ip address.