OpenWrt: what is custom router firmware and how does it work

I router they are essential network components for everyday work. Their correct configuration is crucial to avoid security problems and maximize performance during data transfer. The fact is that even routers are not supported indefinitely by their respective manufacturers: it has happened several times that vulnerabilities present in the firmware are not fixed because the device has now reached its “end of life”. OpenWrt it is a project that has existed for years (the first version dates back to January 2004) and which allows you to update the router with safe and community-supported firmware. Instead of changing routers and increasing the volume of WEEE waste, it is therefore possible to install OpenWrt to give new life to waste disposal devices. networking who were beginning to feel the weight of time.

OpenWrt therefore allows you to recover old devices but also to activate them network functionality which the router manufacturer did not allow access to. Differently than the vast majority of proprietary firmware used on commercial routers, OpenWrt is an open source project. This means that the source code It is publicly available and may be modified and distributed without restriction. This aspect promotes transparency, security and collaboration within the developer community.

What is OpenWrt

OpenWrt is in fact a operating system open source based Linux designed mainly for network devices: routers but also access points, Powerline devices, modems and more. Its main feature is flexibility along with the ability to customize and optimize the software based on specific user needs.

It goes without saying that for each network device you need a specific one firmware OpenWrt: Version 23.05, released mid-October 2023, supports something like 1,800 device models. To check whether the network device you want to update is also supported, just refer to the page Firmware selector and start a search indicating the model of the device on which you want to install OpenWrt.

Who needs additional features on the router and look for a firmware capable of ensuring regular updates, to keep the network device always safe, OpenWrt can be an excellent choice.

Obviously, the firmware modification original of a router is never an operation to be taken lightly. However, if the router has had its day, you are looking for more advanced features or simply the device is no longer supported, installing OpenWrt is a more than sensible operation. The important thing would be to always carry out the operation on a device that is not the one primarily used to connect to the Internet. Conversely, you may see your productivity temporarily disrupted. Furthermore, you might find yourself in trouble if something goes wrong.

The main features of OpenWrt

An advanced firmware like OpenWrt offers a wide range of advanced features to customize and optimize the configuration of routers and other network devices.

First of all, the system integrates a firewall flexible that allows you to control incoming and outgoing traffic, includes support for NAT (Network Address Translation) and the configuration of port forwarding in order to direct incoming traffic to specific open ports on devices connected to the LAN.

OpenWrt also integrates a solid mechanism QoS (Quality of Service) which facilitates the management of available network bandwidth in real time, allowing you to prioritize different types of traffic to improve performance during data transfer.

OpenWrt’s flagship is certainly its VPN support: thanks to compatibility with the OpenVPN and WireGuard VPN protocols, the firmware allows users to configure virtual private networks. They can then be set server VPN to connect remotely to your home or office network, protecting your data and ensuring confidentiality.

OpenWrt unlocks network features and usage modes not included in the original firmware

You can also configure your router as hotspot WiFi or as a wireless repeater to extend network coverage. In this case, OpenWrt allows you to activate specific operating modes not foreseen by the manufacturer of the router itself. Still on the WiFi side, one of the features we appreciate are the advanced configuration possibilities: selection of the WiFi transmission channel, power and so on. In terms of WiFi security we have seen which tricks help and which are useless.

In addition to acting as a DHCP server, as all routers on the market do, devices running OpenWrt can also perform the function of server DNSallowing the resolution of domain names on the local network.

The lightweight web server uHTTPdcan be used to host web pages or administration services while the FTP server and Samba support allow you to share files externally such as on your local network.

How to install OpenWrt

The procedure OpenWrt installation varies from device to device. In some cases, the OpenWrt community provides one Factory Image or a special one firmware version accepted by routine official update. In these cases, the switching to OpenWrt it takes place simply by accessing the router’s administration panel, clicking on the entries Administration/System, Firmware Update or similar, therefore providing as input the customized firmware obtainable through the page Table of hardware. Here it is indicated, for each network device supported by OpenWrt, which version of the software can be installed.

In general, OpenWrt is installed the first time by loading it into the router’s non-volatile memory, into RAM, or by booting over the network (the latter possibility is not supported by all bootloaders).

Boot OpenWrt using your router’s bootloader and an Ethernet port

If, referring to the page Table of hardwareif the direct update to OpenWrt from the router’s administration interface is not foreseen, it is usually possible to install the firmware via the network, relying on a porta Ethernet. The device usually integrates a TFTP/FTP client or server, two protocols for the file transfer Network. Again, some devices use a Web server or the XMODEM protocol.

Before proceeding, with the help of the documentation published in the Table of hardware of OpenWrt, it is essential to note theIP address of the bootloader (may not necessarily correspond to the IP of the device after normal boot with the original firmware…), the protocol used for data exchange, the mode in which the router automatically sets itself (client or server), the port number, the interface to use, the credentials to be specified (where necessary). Finally, it is necessary to check the time window during which the test must be carried out connection to access the device over the network.

At this point, you must prepare the PC which will be connected directly, via Ethernet cable, to the router to be migrated to OpenWrt. The PC’s network card must be configured to use a static IP address within the same network range as the router-side bootloader IP (check the subnet mask).

General indications for carrying out the flashing di OpenWrt are contained on this page: however, it is essential to follow the specific instructions for each device. It is equally essential not to interrupt the update procedure. However, the OpenWrt developers also offer a page with advice for debrickingto be used possibly in emergency situations, when the device no longer responds or does not behave as it should.


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