How to set up a router based on OpenWrt

Possibilities of using OpenWrt

Configuring a router based on OpenWrt provides users with much more possibilities in comparison with standard firmware supplied by router manufacturers: 

• connection via SSH;

• automation of router configuration and management with the help of scripts;

• saving settings in text files;

• using the router for other tasks ("smart home", downloading torrents, SFTP/Web server, etc.).

Besides, OpenWrt developers release OpenWrt updates many times more often and support lasts many times longer than most vendors.

Router requirements for OpenWrt installation

Before reflashing your router and installing OpenWrt, you should check your router for the following requirements:

• compliance with the architectures specified on the official website;

• minimum 4 MB of flash memory, without the ability to install GUI (LuCI);

• at least 32 MB of RAM.

But we must warn you that re-flashing the router often deprives you of the right to use the manufacturer's warranty. It is also possible that the interface of the new shell will be slightly different from the previous one, which may make it a little more difficult to configure the settings.

Basic OpenWrt configuration

Let's consider the OpenWrt flashing algorithm on the example of TP-Link router.

Preparation and flashing.

1.1 First of all you need to know the current firmware version. To do this, go to the admin panel via your browser.

1.2 Now download OpenWrt OS from the link. To do this, in the list of routers, find the firmware that corresponds to the current version (its name should contain the prefix "factory").

1.3 After downloading, go back to the admin panel and click on the "Update" button. After the system prompts you to specify the file, select the OpenWrt archive.

1.4 Wait for the flashing procedure to complete. At this step it is important to ensure power supply without emergency shutdowns so as not to damage the software. If the process took place correctly, after rebooting the web-interface will be available at http://192.168.1.1.

2.Initial configuration of OpenWrt.

2.1 To exclude remote access to the panel by unauthorised persons due to Wi-Fi signal interception, change the administrator password. To do this, go to the "System" — "Administration" menu.

2.2 To enable SSH protocol support, switch the interface to "LAN" mode.

2.3 To remove the warning at the top of the screen, you should log out and log in again. 

3.Wi-Fi set up.

3.1. Go to "Network" — "Wireless".
3.2. Click on the "Edit" button under "radio0 802.11bgn".

Under "Channel", select "auto".
Set "Mode" to "Access Point".
Under "ESSID", enter the name of your OpenWrt network.

Click the "Wireless Security" tab.
Under "Encryption", select "WPA-PSK/WPA2-PSK Mixed Mode".
Under "Key", enter your Wi-Fi password.

4. Configuring Guest Wi-Fi.

The step-by-step algorithm is suitable for 2.4GHz, but it can be used for 5GHz in the same way.
4.1 Go to "Network" — "Wireless" menu.
4.2 Click on the "Add" button in "radio1 802.11bgn".

Under “Channel”, select “auto”.
Under “ESSID”, enter the name of your guest Wi-Fi.
Under “Network”, select “-- custom –” and enter “guest”.

4.3. Go to the Wireless Security tab.
Under “Encryption”, select “WPA-PSK/WPA2-PSK Mixed Mode”.
Under “Key”, enter the password of your guest Wi-Fi.
4.4. Go to “Network” — “Interfaces”.
In the “GUEST” interface, click on the “Edit” button.
Under “Protocol’ select “Static address” and click “Switch protocol”.
Under “IPv4 address” enter “192.168.3.1”.
Under “IPv4 netmask” enter ‘255.255.255.0”.

4.5. Go to the “Firewall settings” tab.
Under "Create / Assign firewall-zone" select "-- custom --" and enter "guest".

4.6. Go to the “DHCP server” tab.
Click on “Setup DHCP server” and then “Save”.
4.7. Go to “Network” — “Firewall”.
Click on the “Edit” button in the “guest” area.
Under “Input” select “reject”.
Under “Allow forward to destination zones”, select “wan”.

4.8. Go to the “Traffic rules” tab.
Click on the “Add” button at the bottom.
Under “Name”, enter “guest DNS”.
Under “Protocol”, enter “TCP+UDP”.
Under “Source zone”, enter “guest”.
Under “Destination zone” select “Device (input)”.
Under “Destination port”, enter “53”.
Click “Save”.

4.9. Click on the “Add” button at the bottom.
Under “Name” enter “guest DHCP”.
Under “Protocol”, specify “UDP”.
Under “Source zone”, specify “guest”.
Under “Destination zone” select “Device (input)”.
Under “Destination port”, enter “67”.
Click “Save”.

In general, OpenWrt is a powerful solution if you want to get maximum control over your router's functionality. Thanks to its extensive customisation options, frequent updates and open source code, this system is far superior to standard firmware. Installing and configuring an OpenWrt router requires care, but the result will be a stable, secure and flexible network that meets your needs.