Edge network security is a critical and challenging issue, as edge computing introduces new vulnerabilities and risks for the network and the data. To protect the data integrity, confidentiality, and availability at the edge nodes and devices, data security techniques such as encryption, authentication, access control, backup, and recovery must be implemented. Network security techniques such as firewalls, intrusion detection, prevention, and response must also be used to protect the network infrastructure, resources, and services from unauthorized or malicious access. Application security techniques such as code review, testing, debugging, and patching must be employed to protect the edge applications and services from errors or exploits. Edge computing is a promising and evolving paradigm that has significant implications for network architecture; thus network engineers need to understand and adapt to this environment in order to design and implement efficient, reliable, and secure solutions.