Why firmware matters Firmware is the low-level software that runs your gateway’s networking functions: Wi‑Fi radios, NAT, firewall rules, telephone ports if present, DHCP, and the web interface you use to configure it. Unlike apps on your phone, router firmware sits between your hardware and the internet, so bugs or vulnerabilities here can compromise performance, privacy, or security for every device on your network. A firmware update can fix critical security holes, add support for standards, improve stability, or—occasionally—introduce new issues. Treat updates as both protection and maintenance, not optional extras.