OpenWrt

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OpenWrt

Developer(s)	openwrt.org
Stable release	Kamikaze 8.09.1 / 2009-06-03; 6 months ago
Operating system	Linux
Type	Router-OS
License	GPL
Website	openwrt.org

OpenWrt is a Linux-based firmware program for embedded devices such as residential gateways. Support was originally limited to the Linksys WRT54G series, but has since been expanded to include other chipsets, manufacturers and device types, including Netgear, D-Link, Asus routers and many others, including the Openmoko mobile phones. The most popular routers seem to be the Linksys WRT54G series and the Asus WL-500g. OpenWrt primarily uses a command-line interface, but also features an optional web-based GUI interface. Technical support is provided through the forums and IRC channel.

The development of OpenWrt was initially aided by the ease of modification afforded by manufacturers' use of software licensed under the GNU General Public License (GPL), which requires manufacturers to release all changes made to code originally licensed under the GPL. Initially using this as a base and later as a reference, developers created a distribution that offers many features not previously found in consumer-level routers. Some features formerly required proprietary software. Before the introduction of OpenWrt 8.09, using Linux 2.6.25, and the b43 kernel module, WLAN for many Broadcom-based routers was only available through the proprietary wl.o module that was also only provided for Linux 2.4.^[1] (Note however that the b43 driver is no longer functional in OpenWrt 8.09.1, due to the removal of the mac80211 driver.^[2])

[edit] Features

OpenWrt offers many of the same features provided in the stock firmware for residential gateways, such as DHCP services and wireless encryption via WEP, Wi-Fi Protected Access, or WPA2. It also offers numerous features that may be absent or poorly-implemented in stock firmware for these devices:

• port forwarding of external traffic to computers behind NAT inside the LAN
• UPnP for dynamically configured port forwarding
• static DHCP leases
• extensive firewall and router configuration
• QoS for applications such as VoIP, online gaming, and streaming media
• configuration of the device as a wireless repeater, wireless access point, wireless bridge, or even a combination of the above
• mesh networking
• use of Dynamic DNS services to maintain a fixed domain name with an ISP that does not provide a static IP address
• command line access via SSH or telnet
• on devices with USB ports, it supports printer sharing, Windows-compatible file sharing (via SAMBA), USB audio, and practically any other device that can be connected
• realtime network monitoring
• an extensive AJAX-enabled web interface, thanks to the LuCI project
• perhaps most importantly: regular bug fixes and updates, even for devices no longer supported by their manufacturers

One novel and useful feature of OpenWrt is its fully writable file system, which allows for package management via the ipkg package system (opkg in recent versions). This makes OpenWrt very versatile and adaptable to different requirements, by allowing users to install new software. This contrasts with other Linux-based firmware, which is often based on a read-only SquashFS filesystem (or similar) that offers efficient compression but no way to modify the installed software without rebuilding and flashing a complete firmware image. OpenWrt achieves good compression by using mini_fo to overlay a writable JFFS2 filesystem over a read-only SquashFS filesystem in a copy-on-write fashion.

[edit] Web interface

A screenshot of the LuCI web interface used by version 8.09.1 of OpenWrt. Here it is being used to configure Dynamic DNS.

Before release 8.09, OpenWrt had a minimal web interface. In release 8.09 of OpenWrt a new, more capable web interface is preinstalled.^[3]. This interface is based on LuCi, an MVC framework written in Lua.^[4]

The X-Wrt project provides an alternate web interface, webif², for current and previous version of OpenWrt. It has more than 40 control and status pages.

[edit] Derivatives

• Chillifire - OpenWrt-based firmware with focus on wireless hotspot management
• Obelisco - (Website in Spanish)
• Midge Linux
• PacketProtector - OpenWrt-based security distribution that includes IDS, IPS, VPN, and web antivirus capabilities.
• Coova - OpenWrt-based with focus on wireless hotspots.
• Freifunk - German software supports wireless mesh networks with OLSR, based on OpenWrt, Available in several languages.
• RO.B.IN - ROBIN (ROuting Batman INside) is an Open Source mesh network project, deployed on top of OpenWrt kamikaze, running on any Atheros AP51 routers such as Meraki Mini or La Fonera and using the B.A.T.M.A.N. routing algorithm.
• Gargoyle Router Firmware - A web interface for OpenWrt that places a strong emphasis on usability
• FreeWRT - A fork of the OpenWrt project.
• X-Wrt - Enhancements to the OpenWrt web interface.

[edit] Sveasoft controversy

On 2006-03-11, the OpenWrt developers publicly announced that Sveasoft had violated its GPL license terms, and that Sveasoft's continuing distribution of OpenWrt was prohibited.^[5] In return, Sveasoft claimed that OpenWrt was illegally redistributing software copyrighted by Sveasoft and Broadcom and placing them under the GPL without being authorized to do so by the copyright holders.^[6] Each group denies the other's allegations.

[edit] See also

Free software portal

• Other WRT54G third-party firmware projects

[edit] References

[edit] External links

• OpenWrt homepage
• Linksys GPL Code Center
• List of available supported packages
• Unofficial OpenWrt package tracker to find ipkg packages on external repositories. These packages are not supported by the OpenWrt community, and using official packages is recommended,
• A large collection of easy to follow tutorials for setting up various services on OpenWrt
• How to trace WiFi frames using OpenWrt, Kismet and Wireshark
• Howtos for configuration of various applications with OpenWrt
• WRT Load Balancer Project
• X-Wrt - End-user adaption of OpenWrt
• Webif² - X-Wrt's enhanced web management console
• LuCI project