To keep your D-Link DSL-3890 AC2300 modem router running at peak performance, it is vital to keep its firmware updated. You can find all the necessary firmware files and official documentation on the D-Link Australia Support Page Direct Download Links
The "story" of the DSL-3890 firmware link is not a simple tale of a download button. It is a drama of internet service providers (ISPs), locked-down hardware, and the eternal struggle between corporate security policies and the end-user’s desire for control. dsl3890 firmware link
Because the ISP customized the firmware to lock the device to their network or pre-configure settings, D-Link cannot legally or technically host that specific firmware file on their public global servers. This is the first major plot hole in the user's journey: the manufacturer’s website disowns the product. To keep your D-Link DSL-3890 AC2300 modem router
Occasionally, D-Link retires older products from their main support page. If you cannot find the link, try these legitimate fallbacks: Because the ISP customized the firmware to lock