Able to use nmrpflash for Netgear Nighthawk R6900v2...

[watchman7777]

Just wanted to report that I was able to unbrick an R6900v2, which isn't on your list, on Windows:

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>dir
Volume in drive C has no label.
Volume Serial Number is 704B-4B56

Directory of C:\Users\kevin\Downloads\R6900v2-V1.2.1.92

05/25/2026 08:52 AM

.
05/25/2026 08:51 AM ..
05/25/2026 08:51 AM 152,590 nmrpflash.exe
05/24/2026 11:22 AM 29,010,747 R6900v2-V1.2.1.92_1.0.1.img
05/24/2026 11:22 AM 789 R6900v2-V1.2.1.92_Release_Notes.html
3 File(s) 29,164,126 bytes
2 Dir(s) 245,389,332,480 bytes free

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>net stop npcap

The Npcap Packet Driver (NPCAP) service was stopped successfully.

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>net start npcap

The Npcap Packet Driver (NPCAP) service was started successfully.

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>nmrpflash -L
eth17 192.168.1.10 34:5a:60:05:fa:c5 (Ethernet)

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>nmrpflash -i eth17 -f R6900v2-V1.2.1.92_1.0.1.img
Waiting for Ethernet connection (Ctrl-C to skip).
Advertising NMRP server on eth17 ...
No response after 60 seconds. Bailing out.

No response from router. Possible causes/fixes:

• Unsupported router
• Wrong Ethernet port - try others if there's more than one
• Hold reset button for a few seconds while powering on router
• Try blind mode (-B option)
  C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>nmrpflash -i eth17 -f R6900v2-V1.2.1.92_1.0.1.img
  Waiting for Ethernet connection (Ctrl-C to skip).
  Advertising NMRP server on eth17 ... |
  Received configuration request from b0:39:56:1a:62:61.
  Sending configuration: 10.164.183.253/24.
  Received upload request.
  Uploading R6900v2-V1.2.1.92_1.0.1.img ... OK (29010747 b)
  Waiting for remote to respond.
  Received keep-alive request (92).
  Remote finished. Closing connection.
  Reboot your device now.

C:\Users\kevin\Downloads\R6900v2-V1.2.1.92>ping 192.168.1.1

Pinging 192.168.1.1 with 32 bytes of data:
Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time<1ms TTL=64
Reply from 192.168.1.1: bytes=32 time<1ms TTL=64

Ping statistics for 192.168.1.1:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

[watchman7777]

The reason for the first failure was that I placed the router into rescue mode. It wouldn't flash. Then I restarted it and just turned it on. nmrpflash immediately began the process.