A firewall is hardware or software that allows communication only between trusted devices over a network such as the Internet. It safeguards your systems by preventing unwanted connections and sending alerts when unwanted devices try to connect. Firewalls can significantly reduce the risk of compromise or abuse. Firewalls are maintained separately from the computers inside the firewalls, so even insecure systems are protected.
Most operating systems provide a host-based firewall product such as Windows Firewall. For departments, IS&T can discuss options for developing a custom network-level firewall for your needs; costs depend on your configuration requirements.
If you need to protect 50 or more systems, schedule a network design consultation.