Bridge (IP Passthrough) stopped working (NR5103E)

[haxxy]

Hi

I lost 5G broadband connectivity through my NR5103E late in the evening of July 13th — I was away when it happened, and I have 2 separate broadband connections with different providers anyway, so I didn't know until I got back; trawling through logs pinpointed the rough time when it occurred.  I had made no changes to my configuration, so whatever happened was a system-related issue.

I have been able to restore the 5G connection by following the instructions I found in the thread "IPv6 Prevented VPN Connection".  However: IP passthrough no longer works.  Based on the IPv6 thread, I'm wondering if the root cause of the original issue was the b14 firmware update; and, if so, perhaps this firmware update is also causing the IP passthrough problem.  But that's really just a guess.  In case it's relevant, though, full firmware version is v1.00(ACBJ.0)b14.

Does anyone have any ideas about how to try troubleshooting/resolving?

Thanks!

[haxxy]

Well... hard for me to see how this might be related, but I noticed that the time server settings in the hub had been reset to pool addresses (perhaps by the firmware update?).  Although the time seemed to be correct, I put them back to my preferred ntp server addresses.  And suddenly everything works.  Posting here just in case it's helpful for anyone, but I suspect it's a coincidence rather than the actual solution to the problem.

[TrotterX]

What time settings did you set it to as I have the same issue ip passthrough suddenly stopped working and I cant get it back, I have restored to default and turned off firewall, set all the NATs to off, set ETHWAN to bridge and turned of wifi and DHCP I have a connection with these settings but as soon as I turn on ip passthrough it looses connection and will not restore until i turn it back off

[bogie67]

I just had the exact same issue. Three 5G modem stopped and I had to return it to factory settings. Then it refused to give my router a public IP address - it just gave the LAN address despite being in IP Pass through mode. After many hours of changing different settings I found the issue. 
Go to Network Setting / Broadband / Cellular APN. Modify Entry 1. Click on APN Manual Mode to reveal the settings. Change PDP Type from IP4/IP6 to IP4. 
Make sure you are in IP Passthrough mode and it should work. 
Note that on the "Broadband" tab I did change ETHWAN from Routing to Bridge. But this stops all traffic so I changed it back to Routing. I believe that is because it is just bridging the LAN/WAN port 2 with the Cellular port. Whereas the router will be plugged into port 1. So shouldn't have any effect anyway other than to kill traffic.