EIGRP Over the Top (OTP) by Arash Deljoo

The EIGRP Over the Top feature enables a single end-to-end Enhanced Interior Gateway Routing Protocol (EIGRP) routing domain that is transparent to the underlying public or private WAN transport that is used for connecting disparate EIGRP customer sites. When an enterprise extends its connectivity across multiple sites through a private or a public WAN connection, the service provider mandates that the enterprise use an additional routing protocol, typically the Border Gateway Protocol (BGP), over the WAN links to ensure end-to-end routing. 

The use of an additional protocol causes additional complexities for the enterprise, such as additional routing processes and sustained interaction between EIGRP and the routing protocol to ensure connectivity, for the enterprise. With the EIGRP Over the Top feature, routing is consolidated into a single protocol (EIGRP) across the WAN, which provides the following benefits:

• There is no dependency on the type of WAN connection used.

 • There is no dependency on the service provider to transfer routes. 

• There is no security threat because the underlying WAN has no knowledge of enterprise routes. 

• This feature simplifies dual carrier deployments and designs by eliminating the need to configure and manage EIGRP-BGP route distribution and route filtering between customer sites.

 • This feature allows easy transition between different service providers. • This feature supports both IPv4 and IPv6 environments.