Answer: the main skills needed are; Configuration of routers and firewalls
Explanation: network security administrator are individuals who are saddled with the responsibilities of managing and monitoring the security over one or more computer networks. They ensure that this networks are free from hacks (both internal and external security threat). They need to know how to configure routers to connect computers together, they also need to be able to configure or set up firewalls (computer defence mechanism) in computer to protect them from hacks or malwares (threats).