Your network and all devices that connect to the network must have the latest security software or firmware installed. You need to check frequently if the manufacturer releases new software in general but keep an eye out for security software or firmware especially. You need to have a firewall that is central to your network and you benefit if your network has a virtual private network (VPN) configured. Finally, your network log files need to be looked at periodically to see if a hacker attempted to get in or successfully did.