4-8
Cisco MWR 1900 Mobile Wireless Edge Router Software Configuration Guide
78-13983-04
Chapter4 Configuring with the Command-Line Interface
Configuring Multilink Interfaces
Configuring Multilink PPP
As higher-speed services are deployed, Multilink-PPP (MLP) provides a standardized method for
spreading traffic across multiple WAN links, while providing multivendor interoperability and
load-balancing on both inbound and outbound traffic.
A Multilink interface is a special virtual interface which represents a multilink PPP bundle. The
multilink interface serves to coordinate the configuration of the bundled link, and presents a single
object for the aggregate links. However, the individual PPP links that are aggregated together, must also
be configured. Therefore, to enable Multilink PPP on multiple serial interfaces, you need to first set up
the multilink interface, and then configure each of the serial interfaces and add them to the same
multilink interface.
The MWR 1900 router can support up to 4 T1 interfaces through the multilink interfac e.
To set up the multilink interface, do the following beginning in global configuration mode:
Step 1 Specify the multilink interface to be configured.
RPM-3(config)# interface multilink number
Step 2 Enable multilink PPP operation.
RPM-3(config-if)# ppp multilink
Step 3 Specify an identification number for the multilink interface.
RPM-3(config-if)# multilink-group group-number
Step 4 Enable IP processing on a the multilink interface without assigning an explicit IP address to the
interface.
RPM-3(config-if)# ip unnumbered loopback number
Where number is the number of the multilink loopback interface that you configured in Configuring
Loopback Interfaces.
Configuring IP Address Assignment
A point-to-point interface must be able to provide a remote node with its IP address through the IP
Control Protocol (IPCP) address negotiation process. The IP addr ess can be obtained from a variety of
sources. The address can be configured through the command line, entered with an EXEC-level
command, provided by TACACS+ or the Dynamic Host Configuration Protocol (DHCP), or from a
locally administered pool.
IP address pooling uses a pool of IP addresses from which an incoming interface can provide an IP
address to a remote node through IPCP address negotiation process. IP address pooling also enhances
configuration flexibility by allowing multiple types of pooling to be active simultaneously.