Microsoft MN700 - Wireless 802.11g Base Station Router User manual

Contents
1 Introduction• 2 Installation• 3 Upgrading Firmware• 4 Resetting Defaults• 5 Reset Button• 6 Hardware Notes
6.1 Firmware
Restoration Mode
♦
6.2 Asus Firmware
Restoration Utility
♦
6.3 NVRAM
Protection
♦
•
7 External Links•
Introduction
The Microsoft MN-700 is essentially a rebadged Asus WL500G WRT. Out-of-the-box it runs a WinCE based
firmware with a crippled bootloader that does not support Linux based firmwares (like DD-WRT). To run
DD-WRT, a new bootloader must be installed through a hardware hack (until someone comes up with a
WinCE killer like the vxworks killer for the Linksys WRT54G v5). The following links provide details
regarding this hack:
Jozerworx version of LiamM's hack♦ LiamM.com♦ Microsoft MN700 Hack Project AsusForums♦ TechIMO.com version of LiamM's hack♦
For those who are wondering, the MN-500 has completely different hardware than the MN-700, so the
instructions provided by the links above work for the MN-700 but not the MN-500. To date, it does not appear
a similar hack for the MN-500 has been discovered yet.
Installation
Note: Support for the MN-700 was officially added after the release of DD-WRT v.23 SP2. Therefore v.23
SP2 and eariler are not supported on the MN-700. Please use build SVN 3953 (link below) or higher. Earlier
builds will brick the router, you will have to clear NVRAM through JTAG (recovery mode will NOT work).
A compatible build (SVN 3953) of DD-WRT is available here.
Follow one (or a combination) of the hardware hack guides listed in the Introduction section above to
get the WL500G Stock Firmware, Oleg's Custom Firmware, or OpenWRT installed and running on
the MN-700.
1.
Download a compatible version of DD-WRT here (SVN 3953).2. Put the WRT in hardware restoration mode (hold down the reset button while powering on the WRT
and wait until the the power light steadily alternates between green and amber).
3.
MN-700
Contents 1

Upload the DD-WRT firmware with the Asus Firmware Restoration Utility. (Available under
"Utilities")
4.
Upgrading Firmware
Once DD-WRT has been installed on the MN-700, new versions can be installed through web interface
(Administration -> Firmware Upgrade). The Asus Firmware Restoration Utility can also be used, but it is no
longer necessary when upgrading DD-WRT.
Resetting Defaults
There are several ways the MN-700's NVRAM can be reset.
Using the Administration -> Factory Defaults web interface.1. Selecting the option to reset to Default Settings when upgrading the firmware through the
Administration -> Firmware Upgrade web interface.
2.
Pressing the reset button while booting (see Reset Button below for MN-700 reset button quirks).3. Last, non-hardware based, resort when the unit won't boot due to a bad setting -- see this forum post.4. Last resort -- use the JTAG connection that originally allowed custom firmware to be installed on the
MN-700 to reset NVRAM.
5.
Reset Button
SVN 3953 and later builds support the reset button. However, the "firmware restoration" mode requires a
change to the standard Linksys "hold reset button for 30 seconds" procedure for resetting the WRT to its
defaults. The following is how the reset button works on the MN-700:
When the WRT is powered on
Holding the reset button for 15-20 seconds will cause the WRT to reboot.♦ Upon reboot, a pressed reset button causes the WRT to go into firmware restoration
mode. This does NOT reset the defaults (see the section below for more information
on the firmware restoration mode).
♦
Since there is little to no warning of the exact instant the WRT will reboot when
holding the reset button, chances are extremely good that the reset button will still be
depressed and cause the WRT to go into firmware restoration mode. Hard booting the
WRT will get the WRT back, but settings will NOT be reset.
♦
When the WRT is booting
Holding the reset button during the boot sequence will reset the unit to its defaults.♦ Care must be taken to press the reset button right after the (amber) power light turns
off immidiately after powering on the WRT and not before, to avoid going into
firmware restoration mode.
♦
MN-700
Installation 2

Based on the above, it should be fairly self-evident that the following procedure is recommended for using the
reset button on the MN-700.
Unplug the WRT1. Plug in the WRT2. The power light will blink, then glow amber3. As soon as the power light turns off, press and hold the reset button4. Hold the reset button until the power and wireless buttons glow green.5. The WRT should now be reset to its defaults6.
Hardware Notes
This section covers observations made about working with the MN-700 hardware. Certian behaviors of this
device are different than other WRTs (especially the Linksys).
Firmware Restoration Mode
The MN-700 (and Asus WL500G AFAIK) has a special pre-boot state that makes it extremely easy to upload
new firmware images, even when the current firmware is corrupt (infact the WRT automatically drops into
this mode when a corrupt firmware is detected during boot). Either applying a new firmware through the Asus
Firmware Restoration Utility (see section below) or a hard reboot (removing the power) is required to exit this
state (Note that entering this state does not negatively effect the current settings or firmware so it is not
especially dangerous to accidentially enter firmware restoration mode -- although it does get in the way of
performing a "reset button" based reset of the WRTs settings as noted in the section above).
To enter firmware restoration mode, simply press the reset button while powering on the WRT and wait until
the power LED alternates between green and amber. The reset button can then be released and the WRT will
stay in this state until the next power cycle or a new firmware has been uploaded.
In this state, the Asus Firmware Restoration Utility (see below) can/should be used to upload new firmware
images.
It does not appear that any particular IP address range is needed to upload firmware in this mode. However, a
valid IP address is required. Since no DHCP server is available in this mode, either the host computer needs a
static IP address or one simply needs to wait for Windows (Win2k and later) to assign an automatic private IP
address in the 169.254.0.0/16 range.
Asus Firmware Restoration Utility
The Asus Firmware Restoration Utility is available from the Asus support site under "Utilities." This is the
preferred utility for uploading new firmware distributions since many firmwares reject a different
distribution's firmware if one attempts to use the web interface.
It appears this utility operates at layer 2 of the OSI model, because it is able to detect WRTs in Firmware
Recovery Mode regardless of the host computer's IP address. I recommend statically assigning an IP address
in the 192.168.1.x range when working with DD-WRT because this is the range DD-WRT defaults to and
WRTs can only be detected once the host has an IP address (DHCP works, but takes longer because the
MN-700
Reset Button 3

DHCP client must first time-out and assign an automatic private IP address before the WRT will be detected
-- and this happens every time the WRT is power cycled because the network connection is lost).
Sometimes the Windows firewall interfers with the Asus Firmware Restoration Utility. When it does, the
utility is not able to find the WRT, but the WRT power LED stops alternating colors and displays a solid
green when one attempts to upload a new firmware file. Either disabling the firewall or making a firewall
exception for the Asus Firmware Restoration Utility solves this problem.
NVRAM Protection
DD-WRT SP2 and earlier do not work with the MN-700 because some NVRAM variables (namely
filter_services1-7) were too long. NVRAM variables >1024 characters in length cause the MN-700 to reset
the NVRAM every reboot. Excessively long NVRAM variables actually brick the MN-700 (the power light is
solid amber when powered on and the unit never boots) and can only be unbricked by resetting NVRAM
through a JTAG connector. I can't define excessively long because I discovered this when working with some
SP2 alpha builds and never calculated the maximum limit (I was just happy to be able to debrick my WRT
and moved on).
This issue manifests itself when changes to the WRT do not survive a reboot.
SP2 and most of the previous versions of DD-WRT exibited this symptom and can technically be made to
work with the MN-700 by manually clearing the filter_services variable (only filter_services2 for SP2) and
commiting nvram after the intial installation of DD-WRT. But doing so is not recommended or supported
because this may cause problems later (especially relating to DD-WRT filters).
The information above is provided to explain the NVRAM protection feature of the MN-700 to aid in
troubleshooting potential future problems should a >1024 NVRAM variable creep back into the DD-WRT
firmware.
External Links
DD-WRT SVN 3953• Microsoft Product Web Site
MS Firmware (requires installing/extracting firmware files from an EXE)♦
•
Asus Support Page for WL500G
Factory firmware available under "firmware"♦ Asus Firmware Restoration Utility available under "utilities"♦
•
MN-700 Hardware Hacking Guides
Jozerworx version of LiamM's hack♦ LiamM.com♦ Microsoft MN700 Hack Project AsusForums♦ TechIMO.com version of LiamM's hack♦
•
Windows JTAG Software
New WinXP EJTAG Debrick Beta .99♦
•
Non-MS firmwares for MN-700
DD-WRT SVN 3953♦ Oleg's Custom Firmware♦ Asus WL500G Stock Firmware♦
•
MN-700
Asus Firmware Restoration Utility 4

OpenWRT♦
MN-700
External Links 5