A firewall is a tool which allows us to protect a computer. Firewalls monitor and block incoming and outgoing connections to a network. A firewall can be software that is installed on a computer, but for larger organisations can be a hardware appliance. To defend against hackers outside of the computer system the firewall can block their incoming connections. If the hacker is inside the system a firewall may prevent data leaving the network
Policies are rules which users of a computer system agree to follow.
The aim of policies is to eliminate human error by limiting what the users can do and identifying how they should act when using computers.
Policies may include:
Users may have to agree to an Acceptible Use Policy which will outline what they can and cannot do on an organisations computers and network. Some network policies can be enforced by the computers for example a computer can prevent a USB drive being accessed by a user if it is set up correctly.
Network policies can also be enforced at different levels using User Access Control.
On a network, users can have different levels of access to control what they can view, edit, and delete. Set-up correctly, user access levels can prevent lower level employees accessing sensitive information, or prevent users accidentally deleting data. In School we use access levels to protect data. Students can only access and edit their own files, Teachers can access and edit student files, their own files, and edit files on shared drives. Without access levels anyone within a school would be able to access any files on the network.
Sometimes an attacker me simply steal or take a computer or device. Computers can by physically attached to furniture or the building to prevent it being stolen. K Locks are a common way to attach laptops, which are easier to steal, to furniture such as tables. Some types of computers, such as servers, might be attached a rack which can be physically bolted to the floor to prevent them from being taken.
Organisations can also put additional physical barriers in place such as locked doors, electronic key card doors, or doors which operate with NFC to prevent unauthorised people accessing computers which contain confidential or personal data.