PPP Multilink Authentication and Configuration

PPP Multilink Protocol (MP) is an extension of PPP that provides the ability to aggregate multiple physical links into a single logical link. This can be useful in situations where higher bandwidth is required, and it also provides redundancy if one of the links fails.

One of the challenges of using multiple physical links is ensuring that packets are evenly distributed across the links. This is where the PPP Multilink Protocol comes in. It provides a way to bundle multiple physical links into a single logical link and distribute the traffic evenly across the links.

PPP Multilink Protocol also supports authentication, which ensures that only authorized users can access the network. The authentication process can be configured using a variety of methods, including PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol).

To configure PPP multilink, the following steps can be followed:

Configure the physical interfaces that will be used for the PPP multilink.

Create a virtual interface for the PPP multilink and configure it with the appropriate IP address, subnet mask, and other settings.

Configure PPP on the physical interfaces and the virtual interface.

Enable PPP multilink on the virtual interface.

Here is an example configuration for PPP multilink authentication using CHAP:

interface serial 0/0/0

encapsulation ppp

ppp authentication chap

interface serial 0/0/1

encapsulation ppp

ppp authentication chap

interface multilink 1

ip address 10.0.0.1 255.255.255.0

ppp multilink

ppp multilink group 1

ppp multilink links minimum 2

ppp multilink interleave

ppp authentication chap

In this example, serial interfaces 0/0/0 and 0/0/1 are configured with CHAP authentication. The multilink interface is then created, and PPP multilink is enabled with a minimum of two links required for the bundle. The ppp multilink interleave command is used to enable interleaving, which distributes packets across the links in a round-robin fashion. Finally, CHAP authentication is configured for the multilink interface.

Once the configuration is complete, the PPP multilink interface can be used like any other interface, and traffic will be distributed across the physical links according to the configured settings.