DNS-120 rev A2
Network Storage Adapter

The D-Link DNS-120 rev A2 router has No WiFi, 1 100mbps ETH-ports and 0 USB-ports.
It is also known as the D-Link Network Storage Adapter.

Quick links:
Default password/Login
Login instructions

DNS-120 rev A2 router specifications (specs)

System specs
CPU: n/a
RAM: 32 MiB
Flash: 4 MiB
Custom firmwares: OpenWrt

Connectivity
WiFi: No ()
WiFi bands: n/a
WiFi throughput: n/a
WAN: None
ETH: 1 x 100mbps port
USB-ports: 0

Hard reset instructions for D-Link DNS-120 rev A2

If your DNS-120 rev A2 router is not working as it should, dropping connections or not being responsive, you should first do a reset of the router to see if the problems persist. Other scenarios where you might want to reset your router is if you've forgotten the password or misconfigured it and can't get access anymore.
Your can reset your D-Link DNS-120 rev A2 in the following way(s):

With the reset button

Locate the reset button on the back off the router
While the unit is powered on, press the reset button with a sharp object (e.g. paperclip)
Hold the button pressed for 10 seconds, then release.
The unit will reboot by itself and once the WLAN light stops blinking the factory reset is done.
You can now setup your router again through the user interface

The 30-30-30 reset

If the above instructions don't work you can always try the 30-30-30 reset as follows:

When router is powered on, press the reset button and hold for 30 seconds. (Use a paper clip or something sharp)
While holding the reset button pressed, unplug the power of the router and hold the reset button for 30 seconds
While still holding the reset button down, turn on the power to the unit again and hold for another 30 seconds.

This process usually works for resetting any router to it's factory setting.

Note: It is worth reading more about how to reset routers with the 30 30 30 reset and what the risks and considerations are when resetting your router this way, instead of just rebooting it.

Default factory settings for D-Link DNS-120 rev A2

If you have performed a reset of your DNS-120 rev A2 device or not changed the defaults, you should be able to access it with the following settings:

Default Gateway IP: 192.168.0.101 D-Link login instructions
Default username: admin D-Link router default password list
Default password: blank
Default subnet mask: 255.255.255.0
Default DNS server: 192.168.0.101
Note: If you are using the default settings you should change them to increase security and prevent unathorized access to your network.

To login to the Network Storage Adapter and change the settings, you can follow these steps:

Make sure you are connected to the router's network, either by Wi-Fi or ethernet cable.
Open your browser and visit http://192.168.0.101
You should be prompted with a login dialogue.
Enter the username: admin and the password blank
Note: If you have already changed the password use that instead.
You will now be logged in. If you haven't yet changed the defaul password, we recommend that you change it first thing you do after logging in.

If these instructions don't work for your router, you can always try a factory reset to get the default, or try some other common D-Link credentials, as they can usually be shared across models/variants.

DNS-120 rev A2 Firmwares

Staying up to date with the latest firmware is a good idea to keep your router even more secure from various security flaws.
If you want to squeeze a little bit of extra functionality out of your router, consider flashing an open-source firmware like dd-wrt, openWRT or LEDE. Flashing a custom ROM can greatly increase the stability and functionality of your old router.
Following are the firmwares that we have identified existing for the D-Link DNS-120 rev A2:

Flashing OpenWrt on the D-Link DNS-120 rev A2

The D-Link DNS-120 rev A2 is supported by OpenWrt according to their Table of Hardware. So flashing OpenWrt onto it should be quite straigthforward.
We couldn't find any specific instructions for flashin OpenWrt on the D-Link DNS-120 rev A2, but since it's listed in their Table of Hardware as supported, you can head over to the OpenWrt install instructions and read on there.
Note: Flashing custom firmwares is always on you're on own risk. Make sure to read OpenWrt's wikis to understand the risks and how to proceed if something goes wrong.

D-Link stock firmware for the DNS-120 rev A2

Stock firmwares for the DNS-120 rev A2 are available under the download section on the modem's support page. You can also refer to the router's manual for instructions on how to upgrade the firmware.