Multilink PPP (also referred to as MP, MPPP, MLP, or Multilink) provides a method for spreading traffic across multiple physical WAN links. Multilink PPP also provides packet fragmentation and reassembly, proper sequencing, multivendor interoperability, and load balancing on inbound and outbound traffic.
MPPP allows packets to be fragmented and sends these fragments simultaneously over multiple point-to-point links to the same remote address. The multiple physical links come up in response to a user-defined load threshold. MPPP can measure the load on just inbound traffic, or on just outbound traffic, but not on the combined load of both inbound and outbound traffic.
Configuring MPPP requires two steps, as shown in the figure.
Step 1. Create a multilink bundle.
- The interface multilink number command creates the multilink interface.
- In interface configuration mode, an IP address is assigned to the multilink interface. In this example, both IPv4 and IPv6 addresses are configured on routers R3 and R4.
- The interface is enabled for multilink PPP.
- The interface is assigned a multilink group number.
Step 2. Assign interfaces to the multilink bundle.
Each interface that is part of the multilink group:
- Is enabled for PPP encapsulation.
- Is enabled for multilink PPP.
- Is bound to the multilink bundle using the multilink group number configured in Step 1.
To disable PPP multilink, use the no ppp multilink command.