LACP Meets SDN - Seamless Link Aggregation to OpenFlow Networks

Today’s local area networks often rely on various methods of aggregating multiple network connections in order to increase throughput beyond what a single link can sustain, and to provide redundancy in case link failures. The Link Aggregation Control Protocol (LACP) provides a method that allows for the automatic bundling of several physical ports together to form such a single logical communication channel on the data link layer. The overall goal is to increase throughput to provide redundancy in case one of the links fail. Using standard switches, however, the redundancy feature is often quite limited. Aggregated links are only allowed between two physical devices. This covers link failures but neglects complete switch outages. The ability of connecting a physical server to two or more individual switches in order to further increase resiliency is only possible with special – and therefore very expensive – stackable switches of the same vendor and type. In this paper we present an OpenFlow approach to overcome the aforementioned limitations of inexpensive common of the shelf switches regarding resilient LACP configurations. To this end, we extended an existing OpenFlow controller and added LACP functionalities. This allows for an seamless integration of end devices using multiple links to increase throughput and redundancy. We present an evaluation of our approach and show that local area networks can benefit significantly from this approach.



  • Markus Steinbacher and Michael Bredel

Part of session

Hardcore Operations

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