  IoT devices are increasingly utilized in critical infrastructure,
enterprises, and households. There are several sophisticated cyber-attacks that
have been reported and many networks have proven vulnerable to both active and
passive attacks by leaking private information, allowing unauthorized access,
and being open to denial of service attacks.
  This paper aims firstly, to assist network operators to understand the need
for an IoT network security solution, and then secondly, to survey IoT network
attack vectors, cyber threats, and countermeasures with a focus on improving
the robustness of existing security solutions. Our first contribution
highlights viewpoints on IoT security from the perspective of stakeholders such
as manufacturers, service providers, consumers, and authorities. We discuss the
differences between IoT and IT systems, the need for IoT security solutions,
and we highlight the key components required for IoT network security system
architecture. For our second contribution, we survey the types of IoT attacks
by grouping them based on their impact. We discuss various attack techniques,
threats, and shortfalls of existing countermeasures with an intention to enable
future research into improving IoT network security.
