  Software Defined Networking (SDN) is a new networking architecture which aims
to provide better decoupling between network control (control plane) and data
forwarding functionalities (data plane). This separation introduces several
benefits, such as a directly programmable and (virtually) centralized network
control. However, researchers showed that the required communication channel
between the control and data plane of SDN creates a potential bottleneck in the
system, introducing new vulnerabilities. Indeed, this behavior could be
exploited to mount powerful attacks, such as the control plane saturation
attack, that can severely hinder the performance of the whole network.
  In this paper we present LineSwitch, an efficient and effective solution
against control plane saturation attack. LineSwitch combines SYN proxy
techniques and probabilistic blacklisting of network traffic. We implemented
LineSwitch as an extension of OpenFlow, the current reference implementation of
SDN, and evaluate our solution considering different traffic scenarios (with
and without attack). The results of our preliminary experiments confirm that,
compared to the state-of-the-art, LineSwitch reduces the time overhead up to
30%, while ensuring the same level of protection.
