D-Link eventually discontinues support for older hardware. If you visit the support site and see that the latest firmware is several years old, it likely means the device has reached "End of Life."
: 802.11n technology providing wireless speeds up to 300 Mbps, backward compatible with 802.11b/g. D-link Dsl-124 Firmware
The D-Link DSL-124 is an entry-level ADSL2/2+ modem/router often sold for home or small-office Internet. "Firmware" for the DSL-124 refers to the router's embedded software that controls modem functions, routing, NAT, firewall, wireless (if present on a variant), VoIP (on some SKUs), management UI, and stability/security fixes. D-Link eventually discontinues support for older hardware
Go back to 192.168.1.1 . Check Status > Device Info to confirm the new firmware version number. wireless (if present on a variant)