Hi

I just bought DGND3800B (DGND3800B-100GRS) and tried to install OpenWRT (backport of 14.07, according to the wiki) but this fails.

Every time i want to upload the openwrt-DGND3800B-squashfs-factory it sais an error has occured (german webinterface). The original FW version is 3.0.0.16.

I already tried to downgrade this version to i.e. 3.0.0.8 but this fails as well (a message in the NEtgear UI like "an error has occured, please check your file").

Can anbody help in this case?

Cheers,

Thomy

(Last edited by Thomymaster on 14 Jun 2015, 21:55)

I think stock OS performs some checks if the image is compatible with its hardware. Make sure that you're loading an appropriate image ( there could be multiple versions of the same model). Most of the stock's UI have a checkbox  like 'don't check' image. Uncheck it at your own risk and try to upload again. If all of those fails you might try to look forward to bootp vmlinux or try luck via uart

I don't know what the message in the 3.0.0.10 firmware means exactly, but could this be a downgrade-prevention thing?

See here:

http://kb.netgear.com/app/answers/detai … rs-only%29

Cheers
Thomy

Hi

Telnet works fine, but i had to change the password from "password" to a different one, otherwise telnetenable doesn't work.

However i cannot do anything from telnet, looks like i have to solder the serial port and use my USB->Serial adapter.

Or does anybody of you know anything?

Sorry for bringing up this topic again, but did you have any luck with downgrading/flashing OpenWRT yet?

If anyone wants to know about my findings:

The login over telnetenable is nearly as good as the login over ssh. You can do quite many things, if you put busybox into your temp folder you can even use dd to backup the partitions before doing anything else.

When you are uploading a new firmware to the router there are some basic checks done with javascripts. Afterwards it is sent to check_upgrade.cgi which will then check the firmware itself. I haven't been able to find the check_upgrade.cgi anywhere on the system using telnet, but modifying the script would maybe help to flash OpenWRT without soldering the serial port.

Hi, I wasn't able to reproduce your problem. Tested several OEM Netgear firmware versions and all allowed to downgrade, even the last DGND3800-V3.0.0.22_3.1.22.chk

Hi, same problem here.
Upgrade to V3.0.0.22 possible, also downgrade to 3.0.0.16 works fine, but no downgrade to 2.0.0.14.
And no flashing through web interface to OpenWRT dgnd3700v1_3800b_backport_12.09.

"Firmware upgrade failed. Please check your file."

Hi, I packaged the Openwrt BB firmware with the OEM tool, version reported by the web upgrade interface should be 3.0.0.23.

https://drive.google.com/file/d/0B-EMoB … sp=sharing

I also included the chk packet tool in the zip file, and a script to generate the factory firmware automatically. Works only under Linux x86 OS. The input file for generating the factory image must be the sysupgrade image, if someone wants to play with this stuff.

Feedback is welcome.

Works fine for me (3800B), not the first time moving from stock/wrt/lede, I'm going to change the "don't work" message in the wiki with a more friendly alert.

2-3 years ago I bought a DGND3800B cause at that time I had a problem with my VDSL Modem and I could not get a proper replacement.I only used it for some days later I brought back my original equipment.

These days I need a more powerfull openwrt based router and I remembered that DGND3800B. It's original Firmware was 3.0.0.10_3.0.10.

To make it short: No way to flash it with any OpenWrt Release.

I systematically tried all available Netgear FW from 3.0.0.10_3.0.10. up to V3.0.0.22_3.1.22. With every version I installed the following OpenWRT/LEDE FW:

- openwrt-DGND3800B-squashfs-factory.chk (V14.07)
- openwrt-15.05-brcm63xx-smp-DGND3800B-squashfs-factory.chk (V15.05)
- lede-17.01.4-brcm63xx-smp-DGND3800B-squashfs-factory.chk (V17.01.4)

The result is always the same, after a few seconds the Webif sends:

"Firmware upgrade failed. Please check your file."

That is the same error I receive if I try to install a firmware before 3.0.0.10_3.0.10 eg. DGND3800B-V3.0.0.8_3.0.8.chk

In the "Release Note for DGND3800B-V3.0.0.10_3.0.10.html" of Netgear 3.0.0.10_3.0.10 FW one can read as new feature:

"Adds check mechanism to prevent the board with new flash downgrade old firmware"

So I think thats the reason for all this problems here.

I saw the picture of the user @danitool here which is showing a downgrade on top of Netgears 3.0.16, I have no explanation why it's working on his router. But with mine I can't reproduce that.

Unfortuantely I'm not familar with the inner life of OpenWRT/LEDE FW so my silly question: Wouldn't it be possible to change the header of the Openwrt/LEDE firmware, so that it is anouncing itself as an realease > V3.0.0.22_3.1.22.

Hi Thomymaster, did you try resetting to factory defaults before downgrading/flashing the new firmware?

Hi danitool,

I don't know whether Thomymaster reset the Router. I did it. And to be 100% sure I just repeated it. Result is the same. I am not able to install another FW, except original Netgear 3.10 - 3.22

Thanks

Does it have a TFTP or CFE recovery mode?  These would let you flash from the bootloader, before the stock firmware even boots, avoiding the check that is in the later stock firmware.

Yes it has that mode but it needs a serial console to use it. The factory firmware should be flasheable using the OEM firmware itself without using the serial console (it requires soldering).

I prefer to solve this issue if possible.

I removed the header (65 bytes) of the OEM V3.0.0.22_3.1.22 firmware. Then, using the chk tool, I regenerated again the header, yielding an exact image (same md5sum). With the same tool and same parameters I did the same for the Openwrt firmware, the version detected by the OEM firmware when upgrading this firmware should be the same ( V3.0.0.22_3.1.22)

kdeiss can you test it? I included also the OEM firmware just to be sure it can also be flashed.

https://drive.google.com/file/d/18Fapmc … sp=sharing

If cannot be flashed, then the problem isn't the version at the Netgear specific header but elsewhere (maybe the broadcom header)

@danitool

you made my blood pressure very high today ;-)

But is working........
So the version information is just inside the header.

Thank you

If I want to upgrade to Chaos Calmer 15.05 I can take that file now?

openwrt-15.05-brcm63xx-smp-DGND3800B-squashfs-factory.chk

Thanks again!

Nice. Thanks for the feedback.

Once you installed Openwrt, you don't need factory firmwares anymore. Use the sysupgrade firmwares instead, this is the latest stable release:

http://downloads.lede-project.org/relea … pgrade.bin

Thank you so much. I made bad experience with LEDE and the MWAN package which I need on this router. So I would prefer to use Chaos Calmer (if have already a nicely running system with these combination). But I can't find a sysupgrade for Chaos Calmer.

I came to this thread from the Wiki (sorry is not allowed me to embed links), I think it would also be nice to update the information there. So I tried it but the Wiki says that I should use the new wiki at openwrt.org (whilest I'm on openwrt.org) . Could you do that?

Thanks

Klaus

For Chaos Calmer use

https://archive.openwrt.org/chaos_calme … fs-cfe.bin

which is the sysupgrade image (and also for flashing from CFE).

I already updated the wiki with the new info. For keeping it simple I upgraded the Barrier Breaker images with this known working header and linked  them into the info box.

https://openwrt.org/toh/netgear/dgnd370 … stallation

Regards

@danitool
I followed your instructions, everything worked how you said. The system is now on Chaos Calmer.

Gran traballo feito con nesta páxina.
Grazas de novo!

Klaus