|  | 8.9 | Security
| 8.9.4 | The use of a firewall as a good practice to ensure network connectivity
A firewall is used to protect the internal network from the public and insecure Internet. Firewalls may be implemented using hardware or software. A software firewall is a set of programs on the gateway, which monitors all traffic flowing in and out of a network and are often implemented using specifically configured routers. All information must go through the firewall and be verified against a specific set of rules. If the information does not meet the specified rules, the data is bounced back and cannot continue until it meets the set standards. An example of hardware firewall is using specially configured routers to control inbound and outbound traffic.