A firewall is a security device or software that monitors network traffic and allows or blocks it according to a set of rules. It sits between a trusted internal network and untrusted networks such as the internet, and acts as the first line of defence against unauthorised access.
Basic firewalls inspect where traffic comes from, where it is going and which port it uses. Next-generation firewalls go further, recognising applications, scanning for known threats, filtering web categories and decrypting traffic for inspection. Rules can be written to allow only what the business needs, such as payment traffic to the payment provider, and to block everything else by default.
In retail and hospitality, firewalls protect POS systems, payment terminals, back-office computers and cameras, and they separate guest Wi-Fi from business systems. Many card-scheme security requirements expect networks that handle payments to be segmented and protected, so a correctly configured firewall supports payment compliance. Firewalls also provide the connection point for VPNs linking stores to head office.
Common pitfalls include leaving default passwords, rules that were opened for a short-term need and never closed, and firmware that is never updated. A firewall installed and then ignored gives false comfort. Logs should be reviewed, configurations backed up and changes documented. Remember too that a firewall does not stop threats that arrive through email, stolen passwords or infected devices, so it works as one layer among several.
Properly managed, a firewall greatly reduces exposure to automated attacks. RetailCare includes firewall configuration and monitoring within its cyber security and network services.