Linksys WRT54G series

Linksys WRT54G version 3.1

Linksys WRT54G version 1.0

Linksys WRT54GS version 1.1

Linksys WRT54G (and variants WRT54GS, WRT54GL, and WRTSL54GS) is a Wi-Fi capable router from Linksys. The device is capable of sharing Internet connections amongst several computers via 802.3 Ethernet and 802.11b/g wireless data links.

The WRT54G is notable for being the first consumer-level network device that had its firmware source code released to satisfy the obligations of the GNU GPL. This allows programmers to modify the firmware to change or add functionality to the device. Several development projects have been started to provide the public with enhanced firmware for the WRT54G. See Third party firmware projects.

Hardware and revisions

WRT54G

The original WRT54G was first released in 2003. It comes with a 4+1 port network switch (the Internet/WAN port is also in the same switch, but on a different VLAN). The devices have two removable antennas connected through Reverse Polarity TNC connectors. The WRT54GC router is an exception and has an internal antenna with optional external antenna. As a cost-cutting measure, the design of the latest version of the WRT54G no longer has detachable antennae or TNC connectors. Instead, version 8 routers simply have two thin wires soldered to the unit's main board. These wires are individually threaded through small plastic stubs to give the appearance of actual external antennae. As a result, Linksys HGA7T and similar external antennae are no longer supported by this model.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	125 MHz	16 MB	4 MB	CDF0 CDF1	20 front panel LEDs (including link/activity, collision detection and speed rating indicators for each RJ-45 port). Wireless capability was provided by a Mini PCI card attached to the router motherboard.
1.1	125 MHz	16 MB	4 MB	CDF2 CDF3	Front panel LEDs reduced to 8 (1 link/activity LED per port, plus one each for power, wireless, DMZ and WAN/Internet connectivity). Wireless chipset integrated onto motherboard.
2.0	200 MHz	16 MB	4 MB	CDF5	Same as 1.1 with a CPU upgrade and greater wireless transmitter integration (fewer transmitter parts). Some of these have 32Mb of RAM but are locked to 16 in the firmware (can be unlocked to use all RAM).
2.1	216 MHz	16 MB	4 MB	CDF6	Same physical appearance as 1.1 and 2.0 models. Some of these models have 32 MB of RAM installed but have been locked to 16 MB by the manufacturer. Some models have 2x16 MB MIRA P2V28S40BTP memory chips.
2.2	216 MHz	16 MB	4 MB	CDF7	Same physical appearance as 1.1 and 2.0 models. Switching chipset from ADMtek 6996L to Broadcom BCM5325EKQM. Some of these models have 32 MB of RAM installed but have been locked to 16 MB by the manufacturer. Some models have 16 MB Hynix HY5DU28162ET-J memory chips.
3.0	216 MHz	16 MB	4 MB	CDF8	Identical to 1.1 and later models, except for the CPU speed and an undocumented switch behind left front panel intended for use with a feature called "SecureEasySetup".
3.1	216 MHz	16 MB	4 MB	CDF9	The Version 3.1 hardware is essentially the same as the Version 3.0 hardware. Adds "SecureEasySetup" button.
4.0	200 MHz	16 MB	4 MB	CDFA	Broadcom BCM5352EKPB Chipset
5.0	200 MHz	8 MB	2 MB	CDFB	Broadcom BCM5352EKPB Chipset - Switched to VxWorks OS and reduced Flash Memory and RAM; not compatible with most 3rd party firmware.
5.1	200 MHz	8 MB	2 MB	CDFC	Broadcom BCM5352EKPB Chipset
5.?	200 MHz	8 MB	2 MB	CDFB	Broadcom BCM5352EKBG Chipset Just discovered (slipped into a 54g V5)
6.0	200 MHz	8 MB	2 MB	CDFD	Broadcom BCM5352EKBG Chipset
7.0		8 MB	2 MB	CDFE	Atheros AR2317 Chipset
8.0	240 MHz	8 MB	2 MB	CDFF	Broadcom BCM5354KFBG Chipset w/non-replaceable antennas.

WRT54GS

The WRT54GS is nearly identical to WRT54G except for additional RAM, flash memory, and SpeedBooster software.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	200 MHz	32 MB	8 MB	CGN0 CGN1	Added SpeedBooster technology (Broadcom Afterburner technology), claims to boost the throughput of 802.11g by 30% (for maximum boost needs SpeedBooster technology on the other side, but will boost standard 802.11g as well)
1.1	200 MHz	32 MB	8 MB	CGN2	Chipset changed from ADMtek 6996L to Broadcom BCM5325EKQM.
2.0	216 MHz	32 MB	8 MB	CGN3	10 LED Front Panel (two new ones behind Cisco logo button). Also capable of SecureEasySetup, but use of the logo button and lighting of the new LEDs behind it requires firmware upgrade.
2.1	216 MHz	32 MB	8 MB	CGN4	Radio chip is changed from BCM2050 to BCM2050KML.
3.0	200 MHz	32 MB	8 MB	CGN5	Use System-on-Chip: processor, MAC, and switching are handled by Broadcom BCM5352EKBP.
4.0	200 MHz	16 MB	4 MB	CGN6	Reduced RAM & Flash
5.0	200 MHz	16 MB	2 MB	CGN7	Uses VxWorks OS and reduced Flash Memory; not compatible with most 3rd party firmware.
5.1	200 MHz	16 MB	2 MB	CGN8
6.0	200 MHz	16 MB	2 MB	CGN9
7.0	240 MHz	16 MB	2 MB	CGNA CGNB	Broadcom BCM5354KFBG Chipset

WRT54GL

Linksys released the WRT54GL in 2005 to support third-party firmware based on Linux, after the original WRT54G line was switched from Linux to VxWorks, starting with version 5.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	200 MHz	16 MB	4 MB	CL7A	New model line, released after the version 5 WRT54G, which returns to a Linux-based internal OS as opposed to the v5's VxWorks firmware. No SpeedBooster enabled in stock state (third party firmwares however, will enable the SpeedBooster feature on this model, as it is a hardware feature). Essentially the same as the WRT54G version 4.0, but with a new model number. One alteration of interest to developers is that the internal numbering scheme of the 4-port switch changed in this model, from 1, 2, 3 and 4 to 3, 2, 1 and 0 respectively.
1.1	200 MHz	16 MB	4 MB	CL7B	No known major differences; however, in June 2007, this version was shipping with firmware revision 4.30.7, while the latest available firmware for the 1.0 version is 4.30.9. This pre-loaded firmware allows the user to upload a 4MB firmware image, whereas the pre-loaded firmware on version 1.0 limited the image to 3MB.

WRTSL54GS

WRTSL54GS is similar to the WRT54GS while adding additional firmware features and a USB 2.0 port (referred to as StorageLink) which can be used for a USB hard disk or flash drive.

Unlike other models, the WRTSL54GS only has one antenna.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	266 MHz	32 MB	8 MB	CJK0	Released after the WRT54GS and WRT54GL. Uses Linux-based OS. Includes SpeedBooster support, additional firmware features, and an external USB 2.0 port (StorageLink) for network storage. Uses 8 MB of Intel TE28F640 flash with a Broadcom BCM4704KPB processor and Broadcom BCM5325FKQM Ethernet switch.
1.1		32 MB	8 MB	CJK11

WRT54GX

WRT54GX comes with SRX (Speed and Range eXpansion), which utilizes True MIMO technology by Airgo Networks. It has 3 antennas and was once marketed as a 'Pre-N' router, with 8 times the speed and 3 times the range over standard 802.11g routers.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	300 MHz	16 MB	4 MB	KBG5?	Wireless-G Broadband Router with SRX. Uses the Broadcom 4704 Chipset
2.0	200 MHz	32 MB	8 MB	KIO1?	Wireless-G Broadband Router with SRX. Uses the Realtek RTL8651B Chipset

WRT54GP2

WRT54GP2 has 1 or 2 antennas, and a built-in analog telephony adapter (ATA) with 2 phone lines, but only 3 network ports.

WRT54GX2

WRT54GX2 has 2 antenna, and was advertised to have 6 times the speed and 2 times the range over standard 802.11g routers.

WRT54GX4

WRT54GX4 has 3 moveable antennas, and is advertised to have 10 times the speed and 3 times the range over standard 802.11g routers.

WRT55AG

WRT54G series with 802.11a support.

WTR54GS

A compact wireless travel router with SpeedBooster support, it only has 1 RJ-45 output.

Version	CPU speed	RAM	Flash memory	S/N Prefix	Notes
1.0	200 MHz	16 MB (IC42S32400)	6 MB (29LV320ABTC)	SJH0	Broadcom BCM5350KPB2 Chipset
2.0	200 MHz	8 MB	2 MB	SJH1	Broadcom BCM5350KPB2 Chipset

WRT54GC

WRT54GC series with 802.11b/g support. This unit has a four port 10/100 switch and one WAN port. The "C" in the router number stands for compact, as the unit measures 4" by 4" by 1" with an internal antenna. The unit can be expanded with addition of HGA7S external antenna to boost range. Hardware Version 1.0 is only option available since introduction in 2005.

The internal hardware is based on a Marvell ARM914 ("Libertas") reference design which is probably identical to the SerComm IP806SM, Xterasys XR-2407G, Abocom ARM914, Hawking HWGR54 Revision M, and the Airlink 101 AR315W. By appropriately changing the value of the firmware byte 0x26, the WRT54GC can be cross-flashed with firmware based on the same reference platform.

There are reports that a sister platform of the WRT54GC (the AR315W) has been hacked to run Linux.

Third-party firmware projects

Although listed here under Linksys, many of these will run on other brands of Linux-based devices, such as the Buffalo network-attached storage series. The extent of support for (and testing on) particular hardware varies from project to project.

• Major Projects
  • DD-WRT Paid and free versions available. (Linux/GPL)
  • HyperWRT Thibor - Firmware based on stock WRT54GS firmware, HyperWRT +tofu and other additions from Thibor.
  • OpenWrt firmware with a JFFS2 file system for package management. (Linux/GPL)
  • Sveasoft Paid and free versions available. Latest versions available via subscription.
  • Tomato Free firmware featuring a number of recent web innovations such as Ajax and SVG graphs. Developed by the programmer of HyperWRT +tofu. The Tomato Manual is available at Wikibooks. (Linux/GPL)

• Minor projects
  • BatBox - RAM based distribution for experimenting, does not change firmware
  • Bluebox - Automatic open Internet scanning and bridging software that runs on WRT54G with OpenWRT.
  • Chillispot - Captive portal software that runs on WRT54G and other platforms, available under GPL
  • Earthlink's IPv6 Firmware - IPv6 feature added to original Linksys firmware (beta-test version)
  • EWRT - Enhanced WRT, with integrated captive portal based on NoCatSplash
  • FON - Chillispot-based worldwide Hotspot network. After unsuccessfully attempting to develop a version that supports 2 SSIDs (one private, one public), FON abandoned the WRT54G series, and now distributes a router called La Fonera, which does support 2 SSIDs.
  • FreeWRT - Experimental firmware based on OpenWrt.
  • Freifunk - German software supports wireless mesh networks with OLSR, based on OpenWrt
  • Meraki - Mesh Networking Wifi AP developed thru Roofnet project, based on OpenWrt.[1]
  • OpennetFirmware - Firmware based on OpenWrt and parts of Freifunk.
  • PacketProtector - OpenWrt-based security distribution that includes IDS, IPS, VPN, and web antivirus capabilities
  • TinyPEAP - Secure wireless authentication feature added to Linksys firmware
  • WiFi-Box - (no documentation available as of January 2006)
  • Neighbornode
  • Tarifa - Based on stock WRT54GL firmware.
  • WiFiDog Captive Portal - WiFi Dog by Ile Sans Fil, a Captive Portal software that runs on the OpenWrt platform
  • WifiTastic - Hotspot solution for home or small business use. Features credit card billing. Runs on the OpenWrt platform
  • Wirds.net A project which uses freifunk firmware with chillispot captive portal and worldspot.net authentication.
  • X-Wrt End user extensions to OpenWrt - provides a nice web based management interface to OpenWrt. (Linux/GPL)

• Deprecated projects (no longer maintained)
  • HyperWRT - Original power boost firmware project by Avenger 2.0 to stay close to official WRT54G and WRT54GS firmware but add features such as transmit power, port triggers, scripts, telnet, etc.
    • HyperWRT +tofu - Based on stock WRT54GS firmware, HyperWRT and some additions.
    • Rupan HyperWRT - Based on stock WRT54G firmware and HyperWRT.

Hardware versions affect firmware compatibility

As of January 2006, most third-party firmware is no longer compatible with version 5 of both the WRT54G and the WRT54GS. The amount of flash memory in the version 5 devices has been reduced to 2 MB, too small for current Linux-based third-party firmware. (See table above for information on identifying the version based on the serial number printed on the bottom of the unit, and on the outside of the shrink-wrapped retail box.)

Some users have succeeded in flashing and running a stripped down but fully functional version of DD-WRT called 'micro' on a version 5 WRT54G. An easier method not requiring any disassembly of the device has since been devised for flashing v5-v6 to DD-WRT.

To support third-party firmware, Linksys has re-released the WRT54G v4, under the new model name WRT54GL (the 'L' in this name allegedly stands for 'Linux').

CPU

According to OpenWRT[2], the Linksys WRT54G series use several different processors, all of them 32-bit MIPS architecture processors manufactured by Broadcom.

Known issues

• As shipped, the Linksys firmware on pre-v5 routers crashes under heavy peer-to-peer network traffic, such as BitTorrent, eMule or other P2P software. The reason for this crash is that Linux's connection tracking by default keeps track of old connections for five days. This five day limit quickly overwhelms the router's internal memory when there are a high number of network connections, and can only be resolved by power cycling the router. For a detailed tutorial on how to permanently fix this issue, see the uTorrent FAQ. Briefly, it involves installing a 3rd party firmware that allows setting the timeout to lower levels, which drops inactive connections and prevents the crashes.

• Earlier versions of the Linksys firmware (before 4.50.00) have a bug that causes interaction problems between players in World of Warcraft.

• Using the default firmware of the WRT54GL it isn't possible to connect to Battle.net in the game Diablo II. Installing third-party firmware (eg, DD-WRT) fixes this port-forwarding issue.

• Earlier versions of the Linksys firmware have a bug that causes problems to wireless PLAYSTATION3(R) connectivity.

• A large number of problems have been reported by Mac users on the latest linksys firmware, with the WRT54G v6. Linksys Forum. The solution appears to be downgrade to firmware 1.00.9.

See also

• BEFW11S4
• WRT150N
• WRT300N
• WRTP54G

External links

• Official WRT54G description page at the Linksys website
• Official WRT54GC description page at the Linksys website
• Official WRT54GL description page at the Linksys website
• Official WRT54GS description page at the Linksys website
• Hendlsofen english tutorials for modding the WRT54GL