Asus RT-N66U

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[[Image:ASUS RT-N66U.jpg | right | 360px]] [[Image:ASUS RT-N66U.jpg | right | 360px]]
-=Hardware=+This 'Dark Night' presents significant risk to bricking that requires careful adherence to the installation process. However, there is a built-in and robust Recovery Mode. The NVRAM issue has been resolved in newer CFE versions (and K3X builds).
-This 'Dark Night' presents significant risk (bricking) that requires careful adherence to the installation process. The NVRAM issue has been resolved, however, knowing what builds can be used must be understood well.+
-==Specifications==+=Hardware [http://en.techinfodepot.shoutwiki.com/wiki/ASUS_RT-N66U Specifications]=
-* Dual Band Router - 2.4GHz and 5GHz bands+{| border="1" cellspacing="0"
-* Wireless controller [http://www.broadcom.com/press/release.php?id=s474934 Broadcom BCM4331]+!CPU
-* MIMO 3x3 on both frequencies (see [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=86437&postdays=0&postorder=asc&start=26 Forum, BrainSlayer])+|Broadcom 4706 @ 600MHz
-* Gigabit LAN and WAN switching+|-
-* 2x USB 2.0 connectors+!Flash/RAM
-* CPU [http://www.broadcom.com/products/Wireless-LAN/802.11-Wireless-LAN-Solutions/BCM4706 Broadcom 4706] @ 600MHz+|32MB / 256MB
-* 256MB RAM+|-
-* 32MB FlashRAM+!Wireless support
-* Built-in Micro SDHC socket +|2.4GHz and 5GHz bands
-* Power supply: DC Output, 19 V, max. 1.58 A current (=> max 30W)+|-
-* Serial header: 8, n, 1, no flow control, 115200. +!Wireless controller
 +|[http://www.broadcom.com/press/release.php?id=s474934 Broadcom BCM4331]
 +|-
 +!MIMO config
 +|3x3 (both bands) (see [https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=86437&start=26 Ref: forum])
 +|-
 +!ETH chip
 +|Broadcom BCM4706
 +|-
 +!Switch
 +|Broadcom BCM53125
 +|-
 +!Ports
 +|Gigabit LAN (4) and WAN (1)
 +|-
 +!USB
 +|2x USB 2.0
 +|-
 +!Other
 +|Micro SDHC socket (internal)
 +|-
 +!Power supply
 +|DC Output, 19 V, max. 1.58 A current (=> max 30W)
 +|-
 +!Serial header
 +|8, n, 1, no flow control, 115200.
 +|}
-====Reset button for Recovery====+===Reset button for Recovery===
-Pressing the Reset button at powerup will put the N66U into recovery mode. +Pressing the Reset button (labeled like ' > o < ') at powerup will put the N66U into recovery mode.
-*Press and hold the reset button while plugging in the power, and keep pressing the reset button for about ten seconds until the power led is blinking slowly, then release the reset button. The router is now in recovery mode: go to 192.168.1.1.+*Press and hold the reset button then plug in power until the power LED starts blinking. Access recovery mode at 192.168.1.1.
-====WPS button to Clear NVRAM====+===WPS button to Clear NVRAM===
-Pressing the Red WPS button at powerup will reset (clear NVRAM) to default settings.+Pressing the WPS button at powerup will reset (clear NVRAM) to default settings.
-*Press and hold the WPS button while plugging in the power, and keep pressing the WPS button for about ten seconds, then release the WPS button. All settings have now been wiped, and default settings will be used.+*Press and hold the WPS button while plugging in the power for about ten seconds. All the LEDs should flash, indicating settings have been reset to default settings.
===NVRAM issue=== ===NVRAM issue===
Line 30: Line 55:
At launch, the RT-N66U was limited to 32k nvram. However, CFE (bootloader) version 1.0.1.3 added 64k nvram support around April 2013, but was not compatible with DD-WRT firmware at that time. For details, see these forum links to historical nvram and 64K implemention discussions: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=86437&postdays=0&postorder=asc&highlight=otrw+light&start=1022 Fractal comments] and [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=163479&start=217 "RT-N66 CFE Thread"] At launch, the RT-N66U was limited to 32k nvram. However, CFE (bootloader) version 1.0.1.3 added 64k nvram support around April 2013, but was not compatible with DD-WRT firmware at that time. For details, see these forum links to historical nvram and 64K implemention discussions: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=86437&postdays=0&postorder=asc&highlight=otrw+light&start=1022 Fractal comments] and [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=163479&start=217 "RT-N66 CFE Thread"]
-This was resolved with DD-WRT K3X builds (kernel 3.x) which extended nvram to 64k, and can be used for any CFE version. It was eventually [https://www.dd-wrt.com/forum/viewtopic.php?p=1112621#1112621 extended to 256k].<br>+This was resolved with DD-WRT K3X builds (kernel 3.x) which extended nvram to 64k, and can be used for any CFE version. It was eventually [https://www.dd-wrt.com/forum/viewtopic.php?p=1112621#1112621 extended to 256k].
-More historical info: http://charleswilkinson.co.uk/2012/12/22/dd-wrt-on-the-asus-rt-n66u-with-64k-cfe/<br>+ 
 +More historical info: http://charleswilkinson.co.uk/2012/12/22/dd-wrt-on-the-asus-rt-n66u-with-64k-cfe/
 + 
'''For newer CFE version updates''' and procedures see here: [https://www.snbforums.com/threads/cfe-bootloader-update.8259/ SNB Forums]<br> '''For newer CFE version updates''' and procedures see here: [https://www.snbforums.com/threads/cfe-bootloader-update.8259/ SNB Forums]<br>
-====CFE Version (or Update)====+Note: CFE can be thought of, as a bootloader for routers. The CFE is what loads the firmware when using ASUS Recovery Utility (and/or a TFTP tool)
-[[Asus_RT-N66U#DD-WRT_Alternatives|AsusWRT-Merlin]] can be installed to enable telnet and check the CFE version, and still be flashed directly to DD.+ 
-*In nvram: nvram get bl_version+=====CFE Version (or Update)=====
-*CFE partition: strings /dev/mtd0ro | grep bl_ver+[[Asus_RT-N66U#DD-WRT_Alternatives|AsusWRT-Merlin]] can be installed to enable telnet/ssh. telnet/ssh and then be used to check the CFE version. DD-WRT can then be flashed directly from Asuswrt-Merlin
 + 
 +Find the CFE version:
 +*in telnet/ssh type: nvram get bl_version
 +*or look at the CFE partition. In telnet/ssh type: strings /dev/mtd0ro | grep bl_ver
 + 
 + 
 +ToDo:
 +* link to Asus CFE sources
 +* determine if updating to latest official Asus Firmware will also update to newest CFE version
 +* newest CFE version (as of July 2020) is 1.0.1.9
 +* how to update the CFE
 + 
 +===K3.X Builds===
 +*Use RT-N66U.trx ''big'' or ''mega'' builds in the ''Broadcom_K3X'' folder. [https://forum.dd-wrt.com/phpBB2/viewtopic.php?p=1150414 Forum note] about the difference between ''mega'' and ''big''
 +*See [[Firmware_FAQ#Where_do_I_download_firmware.3F|Where do I download firmware]] for links and read forum build threads.
 + 
 +Note: do NOT use build 40559 - 40559 is broken for most routers, despite being the recommended build for many routers in the Router Database. Search forum "New build" to get the latest updated info about builds (noted Aug 2020).
 + 
 +===K2.6 Builds===
 +USB (and thus MMC) also does not work in K2.6 builds. USB devices cause a kernel panic: see [http://svn.dd-wrt.com/ticket/2580 SVN ticket]. Use a K3.x build (see above), which also works around the NVRAM issue.
-====K3.X Builds====+Noted Aug 2020: All K2.6 builds after 43136 are likely broken.
-*'''Read the New Build threads on the forums''', such as [https://www.dd-wrt.com/phpBB2/viewtopic.php?t=311722 '''this'''].+
-*Find new builds in the ''Broadcom_K3X'' build folder.+
-*'''8-Mar-2015: 26138 is a good (recommended) build for the RT-N66U:+
-*#[ftp://ftp.dd-wrt.com/betas/2015/02-04-2015-r26138/broadcom_K3X/dd-wrt.v24-26138_NEWD-2_K3.x-big-RT-N66U.trx Big]+
-*#[ftp://ftp.dd-wrt.com/betas/2015/02-04-2015-r26138/broadcom_K3X/dd-wrt.v24-26138_NEWD-2_K3.x_mega_RT-N66U.trx Mega]+
-====K2.6 Builds====+=== DD-WRT Alternatives ===
-'''<font color="red">IMPORTANT: DO NOT USE K2.6 builds</font> if using CFE v1.0.1.3 (64K nvram) or NEWER''', plus USB does not work in K2.6 builds. Any attempt to use a USB device will cause a kernel panic (see this [http://svn.dd-wrt.com/ticket/2580 SVN ticket]. For USB, use a K3.x build, which also works around the NVRAM issues.+User Merlin implemented a solution in mid-2012 to extend the original 32k NVRAM CFE to ~60k NVRAM in firmware
 +* After 380.70 Asuswrt-Merlin stopped supporting RT-N66U. So earlier versions will still work (to enable SSH/Telnet)
 +** Homepage: https://asuswrt.lostrealm.ca/
 +** Download: https://sourceforge.net/projects/asuswrt-merlin/files/
 +**Source code: https://github.com/RMerl/asuswrt-merlin/
 +* For a Asuswrt-Merlin version that still supports RT-N66U
 +** see: [https://www.snbforums.com/threads/fork-asuswrt-merlin-374-43-lts-releases-v44ea.18914/ snbforums post] where the first entry keeps getting updated with the latest information.
-==== DD-WRT Alternatives ==== 
-User Merlin implemented a solution in mid-2012 to extend the original 32k NVRAM CFE to ~60k NVRAM in firmware. 
-*Homepage: https://asuswrt.lostrealm.ca/ 
-*Download: https://sourceforge.net/projects/asuswrt-merlin/files/ 
-*Source code: https://github.com/RMerl/asuswrt-merlin/ 
TomatoUSB [http://tomato.groov.pl/ Shibby] also implemented a 64k NVRAM solution for 32K NVRAM CFE in 2012. TomatoUSB [http://tomato.groov.pl/ Shibby] also implemented a 64k NVRAM solution for 32K NVRAM CFE in 2012.
-====Historical Build Information====+===Historical Build Information===
-*'''25-May-2013''': With the new experimental [ftp://ftp.dd-wrt.com/betas/2013/05-27-2013-r21676/broadcom_K3X-EXPERIMENTAL/ K3.X Broadcom builds], the CFE version is irrelevant. DD-WRT detects it automatically to extend 32KB NVRAM to 64KB. ''Which Image you have to flash, depends on your previous Image (Stock, Merlin, DD-WRT K2.6).''+This is only potentially relevant if using builds from 2015 and earlier.
-* For DD-WRT K2.6: It depends how much NVRAM ( 32KB / 64KB ) you currently have.<br>For 32KB, flash [ftp://ftp.dd-wrt.com/betas/2015/02-04-2015-r26138/broadcom_K3X/dd-wrt.v24-26138_NEWD-2_K3.x_mega_RT-N66U.trx 26138 mega].+*If already running a custom 64K Build like Fractal or Kong with CFE 1.0.1.3, [ftp://ftp.dd-wrt.com/betas/2015/02-04-2015-r26138/broadcom_K3X/dd-wrt.v24-26138_NEWD-2_K3.x_mega-nv64k.bin 26138 mega nv64k] must be used to upgrade. Since K2.6 Builds have an embedded check, you need to use those special nvXXk trailed images. On K3.X this check has been removed and you can simply upgrade from a previous K3.X.
-* If you are already on a custom 64K Build like Fractal or Kong with CFE 1.0.1.3, you need to flash [ftp://ftp.dd-wrt.com/betas/2015/02-04-2015-r26138/broadcom_K3X/dd-wrt.v24-26138_NEWD-2_K3.x_mega-nv64k.bin 26138 mega nv64k]. Since K2.6 Builds have an embedded check, you need to use those special nvXXk trailed images. On K3.X this check has been removed and you can simply upgrade from a previous K3.X.+*With K3.X Broadcom builds, the CFE version is less concerning since DD-WRT detects it automatically to extend the 32KB limitation.
-*'''8-Mar-2015: [http://www.desipro.de/ddwrt-ren/K26/r22000++/kingkong-nv64k-RT-N66U-broadcom.trx Kong 22000++] is a good (recommended) build for the RT-N66U with 64K CFE'''<br>with fix for the serious [http://www.dd-wrt.com/site/content/heartbleed-dd-wrtdd-wrt-online-services Heartbleed vulnerability].+*Build 24461 BRICKS the RT-N66U, but recover is possible through the mini CFE web interface.
-*'''9-Apr-2013:''' It seems more recently manufactured units come pre-loaded with the 64K v1.0.1.3 CFE and so are not compatible with standard DD-WRT builds. Flashing a K2.6 DD-WRT build on these devices will result in a brick.+ 
-*'''26-Jan-2013:''' Current versions of DD-WRT can quickly run out of 32k nvram.+
-*Build 18946 fixes the WAN port issue.+
=Installation Instructions= =Installation Instructions=
-For recommended builds, read the [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=51486 Peacock Announcement], New Build, and model-specific threads.+Read the [[Firmware FAQ]], [https://www.dd-wrt.com/phpBB2/viewtopic.php?t=51486 Peacock Announcement], new build, and model-specific threads.
-===Principle steps===+===Preparation===
-'''For builds and more information''', see here: [https://www.dd-wrt.com/wiki/index.php/Index:FAQ#Where_do_I_download_firmware.3F Where do I download firmware?].<br>+* If upgrading to DD-WRT from other firmwares, then use a '''*.trx''' file, as in '''*_RT-N66U.trx''' file for initial flash and upgrades, '''or only half the memory will be available''' (with ASUS routers, using a *.trx file is always a safe bet).
-'''<font color="red">IMPORTANT: DO NOT USE K2.6 builds</font> if using CFE v1.0.1.3 (64K nvram) or NEWER'''+* If you are upgrading from one version of DD-WRT to a different (newer/older) version of DD-WRT, you can also use the firmwares that end in '''*.bin'''. as in '''_mega.bin''' or '''_big.bin'''
-*Older CFE (32K nvram) can use K2.6: see the above '''K2.6''' and '''K3.X''' sections for details+* '''<font color="red">IMPORTANT:</font>''' determine what version of CFE you have on your router,
-#[[Hard_reset_or_30/30/30|Reset]] or select Factory Default settings.+: '''<font color="red">if CFE v1.0.1.3 (64K nvram) or 'NEWER' - DO NOT USE K2.6 builds</font>'''
-#Install the trailed ASUS RT-N66U version of DD-WRT (file name ends in .trx) using either the Web GUI method or the Recover Utility method. Both methods are described below+* If using Older CFE (32K nvram) you can use K2.6
-#[[Hard_reset_or_30/30/30|Reset]] again+* Reset '''BEFORE''' and '''AFTER''' firmware upload. If upgrading from DD-WRT to a newer version of DD-WRT, then ''before'' is (mainly) optional.
-#"Upgrade" to your final version of DD-WRT (filename ends in .bin) using Web GUI or Recovery Utility+
-#[[Hard_reset_or_30/30/30|Reset]] again+
-'''IMPORTANT:''' [[Hard_reset_or_30/30/30|Reset]] to clear NVRAM (or ''Admin->Factory Default settings'') '''BEFORE''' and '''AFTER''' firmware upload.+
-====Upload Firmware via Web GUI ====+=====Upload via Web GUI =====
-#[[Hard_reset_or_30/30/30|Reset]] or select Factory Default settings. +#[[Asus_RT-N66U#WPS_button_to_Clear_NVRAM|Reset NVRAM via WPS button]] , or select WebGUI option: Factory Default settings.
-#Upload the '''.trx file''' using the stock web GUI. See [https://www.dd-wrt.com/wiki/index.php/Index:FAQ#Where_do_I_download_firmware.3F Where do I download firmware?] for links. See the build threads on the forums for recommendations.+#Upload the DD-WRT build using the stock web GUI (use file ending in .trx or .bin, according to description under [[Asus_RT-N66U#Preparation|Preparation]]).
-#When complete, wait until the router reboots itself, which '''can take at least 10 minutes'''. You want both ping response and web gui response to know that the router is fully rebooted.+#Wait until the router reboots itself, which '''can take at least 10 minutes''' (some times 30 minutes or more). Be patient and wait until you get a response from both ping and the routers WebGUI when you use your PC to access the router.
-#[[Hard_reset_or_30/30/30|Hard reset]] or select Factory Default settings. Wait for the router to reboot itself!!! May take 10 minutes or more+#[[Asus_RT-N66U#WPS_button_to_Clear_NVRAM|Reset NVRAM via WPS button]], or select WebGUI option: Factory Default settings. Wait for the router to reboot!!
-====Upload Firmware via Recovery Utility====+Note: If you are having trouble uploading a newer version of DD-WRT, using the WebGUI, then you might want to try to use a different browser. Sometimes it solves the problem.
 + 
 +=====Upload via ASUS Recovery Utility=====
#Set your computer to a [[Static_IP|static IP]] (e.g. 192.168.1.12), subnet 255.255.255.0, default gateway 192.168.1.1 #Set your computer to a [[Static_IP|static IP]] (e.g. 192.168.1.12), subnet 255.255.255.0, default gateway 192.168.1.1
#Put router into recovery mode by holding down the reset button while powering up the router, wait until the power led is blinking slowly, then release the reset button. #Put router into recovery mode by holding down the reset button while powering up the router, wait until the power led is blinking slowly, then release the reset button.
-#In the Asus Recover utility Access the router’s built in recovery mode by issuing 192.168.1.1 in browser field. +#Access the Asus CFE recovery mode by issuing 192.168.1.1 in browser field.
-#Flash the initial DD-WRT trailed build (with N66U in the name) and upload.+#Browse to select the DD-WRT trailed build ('''N66U big or mega .trx''') then click ''Upload''.
-#When complete, wait until the router reboots itself, which '''can take at least 10 minutes'''. +#Wait until the router reboots itself, which '''can take at least 10 minutes'''.
-#Enter recovery mode again and flash the final DD-WRT build (big or mega with N66U in the name).+#If it doesn't reboot after 30 minutes, power off for 10 seconds, then reset via [[#WPS_button_to_Clear_NVRAM|WPS]]
-#When complete, wait until the router reboots itself again. +#Reset (via WPS) or reenter recovery mode and select to ''Restore defaults NVRAM values''
-#Enter recovery mode again and select to ''Restore defaults NVRAM values''+#*(Optional?) When it completes (should be quick), type this in the browser field then press enter:
-#*When it completes (should be quick), type this in the browser field then press enter:+
#*http://192.168.1.1/do.htm?cmd=nvram+commit #*http://192.168.1.1/do.htm?cmd=nvram+commit
-#Wait until the router reboots itself, which '''can take at least 10 minutes'''. +#Wait until the router reboots itself, then access the DD-WRT GUI at 192.168.1.1 to set a password.
-#Now you should be able to access the DD-WRT GUI at 192.168.1.1 to set a password.+
-====Switching from Tomato====+=====Switching from Tomato=====
-# Download the latest K3.x mega build. See [https://www.dd-wrt.com/wiki/index.php/Index:FAQ#Where_do_I_download_firmware.3F Where do I download firmware?] for links. See the build threads on the forums for recommendations.+#Navigate to the Tomato firmware update page
-# Navigate to the Tomato firmware update page+#*''Administration'' -> ''Upgrade''
-#* Administration > Upgrade+#Upload the firmware you downloaded in step 1
-# Upload the firmware you downloaded in step 1+#The router will reset several times and change its IP address to the default one (192.168.1.1).
-# The router will reset several times and change its IP address to the default one (192.168.1.1).+#Navigate to http://192.168.1.1/Factory_Defaults.asp
-# Navigate to http://192.168.1.1/Factory_Defaults.asp+
#* The login credentials have been reset to the default dd-wrt username/password (root/admin) #* The login credentials have been reset to the default dd-wrt username/password (root/admin)
-# Set "Restore Factory Defaults" to yes and click "Apply Settings".+#Set "Restore Factory Defaults" to yes and click "Apply Settings"
 +#After reboot, set a new user/password
-::Note: Many settings will carry over from Tomato to DD-WRT, but it's highly advisable to reset to factory defaults after flashing, or you risk undesired behavior and instability.+::Note: Reset to factory defaults after flashing from Tomato to DD-WRT to avoid undesired behavior and instability.
=Upgrade to newer DD-WRT= =Upgrade to newer DD-WRT=
-* Clear settings (Clear NVRAM)+* [https://www.dd-wrt.com/wiki/index.php/Asus_RT-N66U#WPS_button_to_Clear_NVRAM Clear settings (Clear NVRAM)]
-* Use the DD-WRT web GUI : Administration -> Firmware upgrade+* Router should revert to default IP (192.168.1.1), so you may have to change your client's IP to the same subnet (e.g. 192.168.1.2).
-* Clear settings (Clear NVRAM)+* Use browser to navigate to 192.168.1.1
-* svn24461 BRICKS RT-N66U. Recover possible through mini CFE webinterface.+* DD-WRT GUI: ''Administration'' -> ''Firmware upgrade''
 +* [https://www.dd-wrt.com/wiki/index.php/Asus_RT-N66U#WPS_button_to_Clear_NVRAM Clear settings (Clear NVRAM)]
=Revert to original ASUS firmware= =Revert to original ASUS firmware=
-* Download firmware from ASUS web site+# Download firmware from ASUS web site
-* Reset to Factory Default Settings or clear NVRAM+# Reset to Factory Default Settings or clear NVRAM
-* Use the DD-WRT web gui: Administration -> Firmware upgrade+# Use the DD-WRT web gui: 'Administration -> Firmware upgrade', to upload the ASUS firmware file you downloaded in step 1.
-* Reset to Factory Default Settings or clear NVRAM+# Reset to Factory Default Settings or clear NVRAM
-=Install an internal MicroSD card=+=Mods=
-Important note:''' USB (and thus MMC) is not supported on K2.6 builds - it causes a kernel panic. However it is working on K3.x builds. See [http://svn.dd-wrt.com/ticket/2580 SVN ticket]+ 
 +===Internal MicroSD card===
 +The N66U has an unused internal MicroSD card slot, but note that USB (and thus MMC) is not supported on K2.6 builds. However, it is working on K3.x builds. See [http://svn.dd-wrt.com/ticket/2580 SVN ticket]
#Open the case #Open the case
Line 132: Line 173:
#* For future access, it is recommended to either snip off the female "U" clips on the top cover, or round off the square edges on the male part of the clip with a nail file. #* For future access, it is recommended to either snip off the female "U" clips on the top cover, or round off the square edges on the male part of the clip with a nail file.
#Install MicroSD card #Install MicroSD card
-#Make use of the MicroSD card+#Enable USB features to utilize the MicroSD card
-In addition to the NAS features of DD-WRT, you can use the extra space to install Optware or [[Adding_Software_Packages_using_Entware-3X|Entware-3X (recommended over Optware)]].+*In addition to DD-WRT NAS features, the extra storage can be used to install Optware or [[Adding_Software_Packages_using_Entware-3X|Entware-3X (recommended over Optware)]] with K3.x builds: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=156013 OTRW Take 2]
 +For easier access, see below.
-Without MMC on K2.6 builds, Optware can't be installed. Use K3.x builds: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=156013 OTRW Take 2]+===Case Top Mod===
 +Spacers (~1/4" to 10mm) can be installed to elevate the case top, which allows easier access to the MicroSD card, and also improve cooling. A piece of dark foam and hole punch can be used to retain the top cover LED lighting.
-=Performance=+===Overclocking===
 +Overclocking works since CFE 1.0.1.3, while underclocking worked prior to that. Overclocking may cause instability, or services (like QoS) to behave unpredictably
 +*Recommended to improve cooling or ventilation when overclocking, like the case top mod
 +*jwh7 has run @663MHz (CFE 1.0.1.9) without issue for 3 years, with an elevated case top
 +*There is one report of QoS degradation at 632Mhz with K3.X big r27360 (06/18/15)
 + 
 +=Notes=
 + 
 +===Performance===
<pre> <pre>
-Test Description RT-N66U+Test Description RT-N66U
-WAN - LAN 732 Mbps+WAN - LAN 732 Mbps
LAN - WAN 729 Mbps LAN - WAN 729 Mbps
-Total Simultaneous 810 Mbps+Total Simultaneous 810 Mbps
Maximum Simultaneous Connections 34,925 Maximum Simultaneous Connections 34,925
Firmware Version 3.1.0.3.90 (stock firmware number) Firmware Version 3.1.0.3.90 (stock firmware number)
Line 148: Line 199:
[http://www.smallnetbuilder.com/wireless/wireless-reviews/31687-asus-rt-n66u-dark-knight-dual-band-wireless-n900-gigabit-router-reviewed?start=2 Sources] and [http://www.smallnetbuilder.com/lanwan/lanwan-howto/31103-how-we-test-hardware-routers-revision-3 testing methods] [http://www.smallnetbuilder.com/wireless/wireless-reviews/31687-asus-rt-n66u-dark-knight-dual-band-wireless-n900-gigabit-router-reviewed?start=2 Sources] and [http://www.smallnetbuilder.com/lanwan/lanwan-howto/31103-how-we-test-hardware-routers-revision-3 testing methods]
-===Overclocking===+===LAN/WAN issue===
-Overclocking works since CFE 1.0.1.3, while underclocking worked prior to that. Overclocking may cause instability, or services (like QoS) to behave unpredictably+There should be no ''vlan0ports'' in nvram for the N66U switch: [https://www.dd-wrt.com/phpBB2/viewtopic.php?p=986347#986347] and [https://www.dd-wrt.com/phpBB2/viewtopic.php?p=936405#936405]<br>
-*Recommended to improve cooling or ventilation when overclocking+
-*One report of QoS degradation at 632Mhz with K3.X big r27360 (06/18/15)+
-=Links and Notes =+===Links===
Primary forum threads Primary forum threads
-* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=171783 One User's Guide] - A users guide for flashing Rt-N66u+* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=171783 One User's Guide] - A users guide for flashing RT-N66U
* Possible ways to update CFE (once a 32k+ CFE is released for this router), see [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=86437&postdays=0&postorder=asc&start=496 LOM post] * Possible ways to update CFE (once a 32k+ CFE is released for this router), see [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=86437&postdays=0&postorder=asc&start=496 LOM post]
*[[Linking_Routers| Linking Routers]] to cover a bigger area with WiFi *[[Linking_Routers| Linking Routers]] to cover a bigger area with WiFi
*Wireless tweaking: [[Basic_Wireless_Settings|Basic Wireless Settings]] and [[Advanced_wireless_settings|Advanced Wireless Settings]] *Wireless tweaking: [[Basic_Wireless_Settings|Basic Wireless Settings]] and [[Advanced_wireless_settings|Advanced Wireless Settings]]
*External antennas: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=43810 The CATFISH thread] *External antennas: [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=43810 The CATFISH thread]
 +* A good 2020 [https://forum.dd-wrt.com/phpBB2/viewtopic.php?t=325439 forum thread]
Additional forum threads Additional forum threads
Line 165: Line 215:
* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=153609&postdays=0&postorder=asc&start=5 Forum: Reason for starting from Build 18946] * [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=153609&postdays=0&postorder=asc&start=5 Forum: Reason for starting from Build 18946]
* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=154818 Forum: N66U and 32k/64k NVRAM issue] * [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=154818 Forum: N66U and 32k/64k NVRAM issue]
-* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=155642 Forum: open case, add MicroSD card]. A 32Gb SD card tested, see [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=155642&start=8 Forum]+* [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=155642 Forum: Open case to add MicroSD card], and a 32Gb card tested [http://www.dd-wrt.com/phpBB2/viewtopic.php?t=155642&start=8 here]
* [http://www.techinfodepot.info/index.php/Asus_RT-N66U_B1 techinfodepot.info on RT-N66U] * [http://www.techinfodepot.info/index.php/Asus_RT-N66U_B1 techinfodepot.info on RT-N66U]
* [http://www.smallnetbuilder.com/wireless/wireless-reviews/31687-asus-rt-n66u-dark-knight-dual-band-wireless-n900-gigabit-router-reviewed SmallNetBuilder Review] * [http://www.smallnetbuilder.com/wireless/wireless-reviews/31687-asus-rt-n66u-dark-knight-dual-band-wireless-n900-gigabit-router-reviewed SmallNetBuilder Review]
* [http://service.asus.com/demoui/RT-N66U/EN/index.html Asus Stock UI demo] * [http://service.asus.com/demoui/RT-N66U/EN/index.html Asus Stock UI demo]
-==More Links== 
-*[https://www.dd-wrt.com/wiki/index.php/Index:FAQ Frequently Asked Questions] 
-*[http://www.dd-wrt.com/phpBB2/viewtopic.php?t=51486 Peacock Announcement]: '''Required reading''' for DD-WRT on Broadcom routers! 
[[Category:Asus guides]] [[Category:Asus guides]]

Current revision

This 'Dark Night' presents significant risk to bricking that requires careful adherence to the installation process. However, there is a built-in and robust Recovery Mode. The NVRAM issue has been resolved in newer CFE versions (and K3X builds).

Contents

[edit] Hardware Specifications

CPU Broadcom 4706 @ 600MHz
Flash/RAM 32MB / 256MB
Wireless support 2.4GHz and 5GHz bands
Wireless controller Broadcom BCM4331
MIMO config 3x3 (both bands) (see Ref: forum)
ETH chip Broadcom BCM4706
Switch Broadcom BCM53125
Ports Gigabit LAN (4) and WAN (1)
USB 2x USB 2.0
Other Micro SDHC socket (internal)
Power supply DC Output, 19 V, max. 1.58 A current (=> max 30W)
Serial header 8, n, 1, no flow control, 115200.

[edit] Reset button for Recovery

Pressing the Reset button (labeled like ' > o < ') at powerup will put the N66U into recovery mode.

  • Press and hold the reset button then plug in power until the power LED starts blinking. Access recovery mode at 192.168.1.1.

[edit] WPS button to Clear NVRAM

Pressing the WPS button at powerup will reset (clear NVRAM) to default settings.

  • Press and hold the WPS button while plugging in the power for about ten seconds. All the LEDs should flash, indicating settings have been reset to default settings.

[edit] NVRAM issue

IMPORTANT: DO NOT USE K2.6 builds if using CFE v1.0.1.3 (64K nvram) or NEWER!!!
At launch, the RT-N66U was limited to 32k nvram. However, CFE (bootloader) version 1.0.1.3 added 64k nvram support around April 2013, but was not compatible with DD-WRT firmware at that time. For details, see these forum links to historical nvram and 64K implemention discussions: Fractal comments and "RT-N66 CFE Thread"

This was resolved with DD-WRT K3X builds (kernel 3.x) which extended nvram to 64k, and can be used for any CFE version. It was eventually extended to 256k.

More historical info: http://charleswilkinson.co.uk/2012/12/22/dd-wrt-on-the-asus-rt-n66u-with-64k-cfe/

For newer CFE version updates and procedures see here: SNB Forums

Note: CFE can be thought of, as a bootloader for routers. The CFE is what loads the firmware when using ASUS Recovery Utility (and/or a TFTP tool)

[edit] CFE Version (or Update)

AsusWRT-Merlin can be installed to enable telnet/ssh. telnet/ssh and then be used to check the CFE version. DD-WRT can then be flashed directly from Asuswrt-Merlin

Find the CFE version:

  • in telnet/ssh type: nvram get bl_version
  • or look at the CFE partition. In telnet/ssh type: strings /dev/mtd0ro | grep bl_ver


ToDo:

  • link to Asus CFE sources
  • determine if updating to latest official Asus Firmware will also update to newest CFE version
  • newest CFE version (as of July 2020) is 1.0.1.9
  • how to update the CFE

[edit] K3.X Builds

Note: do NOT use build 40559 - 40559 is broken for most routers, despite being the recommended build for many routers in the Router Database. Search forum "New build" to get the latest updated info about builds (noted Aug 2020).

[edit] K2.6 Builds

USB (and thus MMC) also does not work in K2.6 builds. USB devices cause a kernel panic: see SVN ticket. Use a K3.x build (see above), which also works around the NVRAM issue.

Noted Aug 2020: All K2.6 builds after 43136 are likely broken.

[edit] DD-WRT Alternatives

User Merlin implemented a solution in mid-2012 to extend the original 32k NVRAM CFE to ~60k NVRAM in firmware

TomatoUSB Shibby also implemented a 64k NVRAM solution for 32K NVRAM CFE in 2012.

[edit] Historical Build Information

This is only potentially relevant if using builds from 2015 and earlier.

  • If already running a custom 64K Build like Fractal or Kong with CFE 1.0.1.3, 26138 mega nv64k must be used to upgrade. Since K2.6 Builds have an embedded check, you need to use those special nvXXk trailed images. On K3.X this check has been removed and you can simply upgrade from a previous K3.X.
  • With K3.X Broadcom builds, the CFE version is less concerning since DD-WRT detects it automatically to extend the 32KB limitation.
  • Build 24461 BRICKS the RT-N66U, but recover is possible through the mini CFE web interface.


[edit] Installation Instructions

Read the Firmware FAQ, Peacock Announcement, new build, and model-specific threads.

[edit] Preparation

  • If upgrading to DD-WRT from other firmwares, then use a *.trx file, as in *_RT-N66U.trx file for initial flash and upgrades, or only half the memory will be available (with ASUS routers, using a *.trx file is always a safe bet).
  • If you are upgrading from one version of DD-WRT to a different (newer/older) version of DD-WRT, you can also use the firmwares that end in *.bin. as in _mega.bin or _big.bin
  • IMPORTANT: determine what version of CFE you have on your router,
if CFE v1.0.1.3 (64K nvram) or 'NEWER' - DO NOT USE K2.6 builds
  • If using Older CFE (32K nvram) you can use K2.6
  • Reset BEFORE and AFTER firmware upload. If upgrading from DD-WRT to a newer version of DD-WRT, then before is (mainly) optional.
[edit] Upload via Web GUI
  1. Reset NVRAM via WPS button , or select WebGUI option: Factory Default settings.
  2. Upload the DD-WRT build using the stock web GUI (use file ending in .trx or .bin, according to description under Preparation).
  3. Wait until the router reboots itself, which can take at least 10 minutes (some times 30 minutes or more). Be patient and wait until you get a response from both ping and the routers WebGUI when you use your PC to access the router.
  4. Reset NVRAM via WPS button, or select WebGUI option: Factory Default settings. Wait for the router to reboot!!

Note: If you are having trouble uploading a newer version of DD-WRT, using the WebGUI, then you might want to try to use a different browser. Sometimes it solves the problem.

[edit] Upload via ASUS Recovery Utility
  1. Set your computer to a static IP (e.g. 192.168.1.12), subnet 255.255.255.0, default gateway 192.168.1.1
  2. Put router into recovery mode by holding down the reset button while powering up the router, wait until the power led is blinking slowly, then release the reset button.
  3. Access the Asus CFE recovery mode by issuing 192.168.1.1 in browser field.
  4. Browse to select the DD-WRT trailed build (N66U big or mega .trx) then click Upload.
  5. Wait until the router reboots itself, which can take at least 10 minutes.
  6. If it doesn't reboot after 30 minutes, power off for 10 seconds, then reset via WPS
  7. Reset (via WPS) or reenter recovery mode and select to Restore defaults NVRAM values
  8. Wait until the router reboots itself, then access the DD-WRT GUI at 192.168.1.1 to set a password.
[edit] Switching from Tomato
  1. Navigate to the Tomato firmware update page
    • Administration -> Upgrade
  2. Upload the firmware you downloaded in step 1
  3. The router will reset several times and change its IP address to the default one (192.168.1.1).
  4. Navigate to http://192.168.1.1/Factory_Defaults.asp
    • The login credentials have been reset to the default dd-wrt username/password (root/admin)
  5. Set "Restore Factory Defaults" to yes and click "Apply Settings"
  6. After reboot, set a new user/password
Note: Reset to factory defaults after flashing from Tomato to DD-WRT to avoid undesired behavior and instability.

[edit] Upgrade to newer DD-WRT

[edit] Revert to original ASUS firmware

  1. Download firmware from ASUS web site
  2. Reset to Factory Default Settings or clear NVRAM
  3. Use the DD-WRT web gui: 'Administration -> Firmware upgrade', to upload the ASUS firmware file you downloaded in step 1.
  4. Reset to Factory Default Settings or clear NVRAM

[edit] Mods

[edit] Internal MicroSD card

The N66U has an unused internal MicroSD card slot, but note that USB (and thus MMC) is not supported on K2.6 builds. However, it is working on K3.x builds. See SVN ticket

  1. Open the case
    • Unscrew the four screws at the bottom
    • Then you want to release the plastic clips that holds the top and bottom parts together.
    • Pry the bottom case outward, which has the male clips.
    • For future access, it is recommended to either snip off the female "U" clips on the top cover, or round off the square edges on the male part of the clip with a nail file.
  2. Install MicroSD card
  3. Enable USB features to utilize the MicroSD card

For easier access, see below.

[edit] Case Top Mod

Spacers (~1/4" to 10mm) can be installed to elevate the case top, which allows easier access to the MicroSD card, and also improve cooling. A piece of dark foam and hole punch can be used to retain the top cover LED lighting.

[edit] Overclocking

Overclocking works since CFE 1.0.1.3, while underclocking worked prior to that. Overclocking may cause instability, or services (like QoS) to behave unpredictably

  • Recommended to improve cooling or ventilation when overclocking, like the case top mod
  • jwh7 has run @663MHz (CFE 1.0.1.9) without issue for 3 years, with an elevated case top
  • There is one report of QoS degradation at 632Mhz with K3.X big r27360 (06/18/15)

[edit] Notes

[edit] Performance

Test Description                                 RT-N66U
WAN - LAN	                                 732 Mbps
LAN - WAN                                         729 Mbps
Total Simultaneous                              810 Mbps
Maximum Simultaneous Connections   34,925
Firmware Version                                3.1.0.3.90  (stock firmware number)

Sources and testing methods

[edit] LAN/WAN issue

There should be no vlan0ports in nvram for the N66U switch: [1] and [2]

[edit] Links

Primary forum threads

Additional forum threads