Configuring IPCP Options
For interfaces with PPP encapsulation, you can configure IPCP to negotiate IP address assignments and to pass network-related information such as Windows Name Service (WINS) and Domain Name System (DNS) servers, as defined in RFC 1877, PPP Internet Protocol Control Protocol Extensions for Name Server Addresses.
 | Note: The Junos OS does not request name servers from the remote end; the software does, however, send name servers to the remote end if requested. |
On the logical interface, the following PPP encapsulation types are supported:
- atm-mlppp-llc
- atm-ppp-llc
- atm-ppp-vc-mux
- multilink-ppp
When you enable a PPP interface, you can configure an IP address, enable the interface to negotiate an IP address assignment from the remote end, or allow the interface to be unnumbered. You can also assign a destination profile to the remote end. The destination profile includes PPP properties, such as primary and secondary DNS and NetBIOS Name Servers (NBNSs). These options are described in the following sections:
Configuring an IP Address for an Interface
You can configure an IP address for the interface by including the address statement in the configuration. For more information, see Configuring the Interface Address.
If you include the address statement in the configuration, you cannot include the negotiate-address or unnumbered-address statement in the configuration.
When you include the address statement in the interface configuration, you can assign PPP properties to the remote end, as shown in Assigning a Destination Profile to the Remote End.
| Note: The option to negotiate an IP address is not allowed in MLFR and MFR encapsulations. |
Negotiating an IP Address Assignment from the Remote End
To enable the interface to obtain an IP address from the remote end, include the negotiate-address statement:
You can include this statement at the following hierarchy levels:
- [edit interfaces interface-name unit logical-unit-number family inet]
- [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet]
If you include the negotiate-address statement in the configuration, you cannot include the address or unnumbered-address statement in the configuration.
Configuring an Interface to Be Unnumbered
To configure an interface to be unnumbered, include the unnumbered-address and destination statements in the configuration:
The unnumbered-address statement enables the local address to be derived from the specified interface. The interface name must include a logical unit number and must have a configured address (see Configuring the Interface Address). Specify the IP address of the remote interface with the destination statement.
You can include these statements at the following hierarchy levels:
- [edit interfaces interface-name unit logical-unit-number family inet]
- [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet]
If you include the unnumbered-address statement in the configuration, you cannot include the address or negotiate-address statement in the interface configuration.
When you include the unnumbered-address statement in the interface configuration, you can assign PPP properties to the remote end, as shown in Assigning a Destination Profile to the Remote End.
Assigning a Destination Profile to the Remote End
When you include the address or unnumbered-address statement in the interface configuration, you can assign PPP properties to the remote end. To do this, include the destination-profile statement:
You can include this statement at the following hierarchy levels:
- [edit interfaces interface-name unit logical-unit-number family inet address address]
- [edit interfaces interface-name unit logical-unit-number family inet unnumbered-address interface-name]
- [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet address address]
- [edit logical-systems logical-system-name interfaces interface-name unit logical-unit-number family inet unnumbered-address interface-name]
The profile name is a PPP group profile. You define the profile by including the following statements at the [edit access group-profile name ppp] hierarchy level:
For more information about PPP group profiles, see the Junos OS System Basics Configuration Guide.
