Sha256sum seems to not match

Installing and Using OpenWrt
1

I seem to have bricked my router (Netgear WNDR4500v3) - stupidly went to sleep momentarily and did a sysupgrade of the wrong router upgrade.
I can ping it but not much else, somebody is in there.
So now trying to recover by using tftp to upload.
Using Linux Mint 21.1 with kernel 5.15.0-91-generic x86_64 and tftp-hpa.
Also tried atftp - still chksum error.

tftp fails with this:

tftp -v -v -v -m binary -c put openwrt-23.05.0-ath79-nand-netgear_wndr4500-v3-initramfs-kernel.bin 192.168.1.1
mode set to octet
(to) tm
Connected to tm (192.168.1.1), port 69
putting openwrt-23.05.0-ath79-nand-netgear_wndr4500-v3-initramfs-kernel.bin to tm:192.168.1.1 [octet]
Error code 2: File has bad checksum
Sent 5860864 bytes in -4.5 seconds [-10319922 bit/s]

The Openwrt download page shows sha256sum:

sha256sum: 247c48abdc0392ebd08f4a27040ef428511a09493cc678849965456de032ecc9

running my sha256sum gives this:
sha256sum -b openwrt-23.05.0-ath79-nand-netgear_wndr4500-v3-initramfs-kernel.bin
678ed5db40234c706ce45ba66ccb28fea9017820e32fd69031dc37b54f304189 *openwrt-23.05.0-ath79-nand-netgear_wndr4500-v3-initramfs-kernel.bin

What am I doing wrong?
Oh, and BTW, why does tftp-hpa always ask for my host, and it seems to be doing octet instead of binary.

Thanks,

Jimmy

2

in case it has DHCP and is pingable, it is maybe not broken.

  • Which "wrong" image did you flash, can you post the exact filename?

  • does https://192.168.1.1 show anything, if you connect your workstation to a LAN port and have the WAN port unplugged?

  • Can you post the url of the web site of the recovery method description that you are trying to execute?

3

Only one wired ethernet on laptop - wireless disabled.
DHCP - nope. No address shows on my laptop.

Wrong image flashed: openwrt-23.05.2-apm821xx-nand-netgear_wndr4700-initramfs-kernel.bin
Am using this page to try to fix: https://openwrt.org/docs/guide-user/troubleshooting/generic.debrick
Where it says " installed OpenWrt via bootloader." Hoping, since it pings, still has a bootloader. But can't get past the bad cksum thing.

Thanks for replying,

Jimmy

4

I dont own a netgear. The wiki does not seem to have a more device-specific recovery doc. But it sound like the bootloader can recover the firmware partition with the right steps.
Is the netgear recovery doc of any help? https://kb.netgear.com/000059633/How-do-I-upload-firmware-to-my-NETGEAR-router-using-a-TFTP-client-on-Microsoft-Windows

I would tend to say, to first try recover to an official netgear firmware file and then redo OpenWRT installation as a second step.

If no one else posts here, you could also ask the netgear.com user forum community, if there is any more specific option for recovery of this device.

PS: (Not sure, if still possible) I would recommend changing the thread title to: Problem to unbrick Netgear WNDR4500v3

5

Just noticed my last reply is not here. Replied to an email, but guess that didn't work. Anyway, solved as shown below.
Hooray (almost).
Your idea worked - now have Netgear software installed - had to do a couple times, but 3rd was a charm.
Then used Netgear software to install the Openwrt factory image and it is working.

Thanks so much. Dunno if I would've thought about reinstalling Netgear stuff.

6

:grin::+1:. Thanks for reporting back. Good to see that it worked,
If you want to help future users reading this thread, maybe post a quick note of which exact recovery step documentation did help for recovery of your device.

7

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