  The advancement in cloud networks has enabled connectivity of both
traditional networked elements and new devices from all walks of life, thereby
forming the Internet of Things (IoT). In an IoT setting, improving and scaling
network components as well as reducing cost is essential to sustain exponential
growth. In this domain, software-defined networking (SDN) is revolutionizing
the network infrastructure with a new paradigm. SDN splits the control/routing
logic from the data transfer/forwarding. This splitting causes many issues in
SDN, such as vulnerabilities of DDoS attacks. Many solutions (including
blockchain based) have been proposed to overcome these problems. In this work,
we offer a blockchain-based solution that is provided in redundant SDN
(load-balanced) to service millions of IoT devices. Blockchain is considered as
tamper-proof and impossible to corrupt due to the replication of the ledger and
consensus for verification and addition to the ledger. Therefore, it is a
perfect fit for SDN in IoT Networks. Blockchain technology provides everyone
with a working proof of decentralized trust. The experimental results show gain
and efficiency with respect to the accuracy, update process, and bandwidth
utilization.
