I noticed on more than 10 DIR-300/NRU/B7 routers that they hang periodically, the Internet disappears, and if the router is included in an unmanaged switch, then the DIR-300/NRU/B7 also hangs it. All official firmware up to 1.4.8 did not solve the problem.
It was possible to solve the problem only with modified firmware from Zyxel Keenetic Lite.
I will describe in order the points that must be completed to achieve the result:
1) Download the archive with modified firmware KEENETIC_LITE and unpack it
https://files.ixnfo.com/Firmware/KEENETIC_LITE/KEENETIC_LITE-V1.00AABL.1D0_fixed_for_4MB_flash.zip
2) On the computer’s network adapter, we manually specify the IP address and subnet mask, for example, 192.168.0.2, 255.255.255.0.
3) Put the router in recovery mode. To do this, turn it off, hold the “reset” button and without releasing it, turn on the power, after which “reset” continue to hold for about 15-30 seconds and release it.
4) In any browser, open the web interface of the router by typing 192.168.0.1, the “Failsafe UI” window should open in which by clicking the “Browse” button we indicate the firmware file downloaded and unpacked from the archive. To start the firmware update procedure, click the “Send Request” button.
At the end, the router will reboot. The standard IP of the router will be 192.168.1.1, login – admin, password – 1234.
Done. Do not forget to return the IP address settings to automatic on the computer’s network adapter.
See also my articles:
Restoring D-Link DIR-300NRU/B7 Router
Configuring the D-Link DIR-300NRU/B7 Router