[Plebeian]

Hello, I recently purchased a used WZR-600DHP which annoyingly came with OpenWRT installed and I would like to switch it back to DD-WRT, either the customized DD-WRT build that Buffalo produces or normal DD-WRT.

After a fair bit of googling, the general consensus seems to be for any router that you should always revert back to the stock firmware before attempting to install DD-WRT when going from OpenWRT, but usually they mention specifically named firmware images such as RouterNameToStock.bin that have been made for this purpose to be used from the WebGUI and I can't seem to find anything like that for the WZR-600DHP.

This leaves me with quite a few options, none of which I'm sure about.

1.) Load the DD-WRT firmware via TFTP when the router boots up. I'm fairly sure this is the most reliable and bulletproof method but looks like a bit of a pain to get the timing right.

2.) Force the router into "failsafe" which is an OpenWRT feature, then use telnet/putty commands to load the new firmware. Not sure if this would cause any problems or not, perhaps it only expects to be receiving another OpenWRT image?

3.) Telnet into the router as it's running OpenWRT and do the same or similar commands to run the firmware upgrade, again not sure about this.

4.) Be lazy and just attempt to load a DD-WRT firmware via OpenWRT's web upgrade interface, potentially risking a brick.

Thanks for your help in saving me some time and/or a brick

Relevant links:
https://wiki.openwrt.org/toh/buffalo/wzr-600dhp
https://wiki.openwrt.org/doc/howto/generic.failsafe#flash_new_firmware_in_failsafe_mode
https://www.dd-wrt.com/wiki/index.php/Buffalo_WZR-HP-AG300H
https://www.buffalotech.com/products/airstation-highpower-n600-gigabit-dual-band-open-source-dd-wrt-wireless-rou

[Plebeian]

Update & TLDR: Have managed to flash the Buffalo version of DD-WRT via TFTP, gonna try it for a little while before I follow the usual webflash process to get it running normal DD-WRT

Long version: In case this thread is useful to future searches, I may as well document my struggle. I went with option 3 at first running the following command after using WinSCP to transfer a community build of DDWRT to the router.

mtd -r write /tmp/firmwarename.bin firmware

This resulted in a brick and intermittently blinking red diag light boot mode, yep looks like I completely screwed that one up.

To resolve this, I first attempted to TFTP on Windows 10 with little success, eventually I gave up and dusted off a Linux laptop.

On Linux, I followed some other dudes process that I found on Google.

http://g300nh.blogspot.co.nz/2010/06/firmware-flash-and-brick-recovery.html

However, for 600DHP, I entered the mac address of 02:AA:BB:CC:DD:20 as that's meant to be the MAC of the boot loader on the 600DHP.

Here's pretty much all the commands I wrote, excluding others for getting the firmware file I wanted onto the Linux box itself.

sudo apt-get update
sudo apt-get install tftp-hpa
sudo /etc/init.d/networking stop
sudo ifconfig eth0 192.168.11.2 (replace eith0 with your particular interface name in Linux)
sudo ifconfig eth0 netmask 255.255.255.0
sudo arp -s 192.168.11.1 02:AA:BB:CC:DD:20
tftp 192.168.11.1
verbose
binary
trace
rexmt 1
timeout 60
put firmwarename.enc

And hey presto it worked first time, yay for Linux

[Detection]

Reverting to stock before switching from one firmware to the other is usually done by just flashing stock via the webUI then DD-WRT's Factory-to-DDWRT image, then the full DDWRT image

Never seen any custom-to-stock image that need flashing before flashing stock, plus they would also be custom anyway

[Malachi]

Buffalo units are different. They require an unencrypted oem firmware. Search the forum.