nmrpflash doesn't work on RBS750 (and seems others) that are in the boot loop mode

[a1ch3mist]

Orbi can get into boot loop mode, where about every minute it does a full cycle. This seems too short for all the Orbi services to start up, like DHCP.

nmrpflash will get to adding the IP to the interface, and you can see the PC trying to connect. However, I never get a configuration request from the router/satellite.

On reddit, I found someone who discovered a new mode of TFTP receiving firmware. Hold sync + reset before powering on the device and it goes into a yellow light status. However, that didn't help with pinging or using tftpd or nmrp, but it is interesting and prevents the boot loop.

If there's any way to get nmrpflash to work in this failure mode of boot loop, please advise! I see many people have had this issue but I haven't found anyone actually resolve it.

[jclehner]

Have you tried these instructions?

[a1ch3mist]

Have you tried these instructions?

Yes I have tried that multiple times. No luck.

[jclehner]

On reddit, I found someone who discovered a new mode of TFTP receiving firmware.

Is it this post? What's interesting is that in their case, NMRP is running on the router (indicated by the Client starts...[Listening] for ADVERTISE... message), so in theory nmrpflash should have worked.

EDIT: Just noticed that further down that they mentioned "I can't ping to 192.168.1.1 which should be the RBS750, so the program is not able to load the firmware (tftp - nmrpflash - tftpd64)".

Yes I have tried that multiple times. No luck.

Have you tried all Ethernet ports?

[jclehner]

Quick followup. In the screenshots posted on reddit, what looks wrong are the following messages:

eth0 PHY0 Down Speed :10 Half duplex
eth0 PHY1 Down Speed :10 Half duplex
eth0 PHY2 Down Speed :10 Half duplex
eth0 PHY3 Down Speed :10 Half duplex
eth0 PHY4 Down Speed :10 Half duplex

This would indicate that despite an Ethernet cable being plugged in (according to the photos), it isn't even being detected.
That would explain why not even ping would work. Could indicate a hardware issue.

Unfortunately, they didn't post a screenshot of the console output when the reboot happens.

[jclehner]

Also, have you tried -B (blind mode)? For this to work however, the router would still need to be able to receive packets (but not send them).

[ghuge]

I had the same problem on my RBR750 , Here is the log

nmrpflash.exe -v -i net13 -f RBR750-V3.chk -m 38:94:ed:4c:a0:f6 -B
Waiting for Ethernet connection (Ctrl-C to skip).
Adding 10.164.183.252 to interface net13.
Advertising NMRP server on net13 ... |
Received configuration request from 38:94:ed:4c:a0:f6.
Sending configuration: 10.164.183.253/24.
Received upload request: filename 'firmware'.
Using remote filename 'firmware'.
Uploading RBR750-V3.chk ... Warning: TFTP block rollover. Upload might fail!
OK (37622386 b)
Waiting for remote to respond.
Received upload request: filename 'firmware'.
Using remote filename 'firmware'.
Uploading RBR750-V3.chk ... Timeout while waiting for ACK(0)/OACK.

Firmware file rejected by router. Possible causes:

• Wrong firmware file (model number correct?)
• Wrong file format (e.g. .chk vs .trx file)
• Downgrading to a lower version number

[ghuge]

BTW, anyone know how to TTL in RBR750. I opened the case , find a port, use a USB-TTL TRANSFER, but nothing in my putty.

[jclehner]

@ghuge Your problem seems to be different.

Please try the .exe file listed in this post