Multi WAN dpinger not working.

[jdrake4]

I have been using Opnsense for a number for a few years, but am no expert.
I have two WAN connections setup, (DSL and a 5g Wireless) and this was working fine for well over a year. in about the last month or so i noticed the 5g wireless was offline. The Monitor IP was 8.8.8.8 but i swapped it to 1.1.1.1 to make sure was not something weird with the other DNS monitor IP. The DSL monitor IP is now 1.0.0.1, the RTT delay is about 20ms on average. If I use a monitor IP the 5g connection the RTT shows like 17,000ms and the port goes offline.
If i disable gateway monitoring on the 5g gateway the port starts to work no real issues. I can even disable the DSL gateway and ping the monitor IP on a command line on a connected PC and my delay is about 30 to 50ms.

To do additional troubleshooting I moved to a different Ethernet port on the 5g gateway and configured another port on the opnsense box to make sure there is not some issue with the Ethernet port. i have also tried to configure the port as 1g full duplex and that has not helped. This all worked fine maybe a month ago, (possibly longer as it could have failed over to DSL and i would not have noticed it for a while). I also tried reinstalling Opnsense from USB and importing the backup and still no luck.

Any thoughts or ideas would be greatly appreciated.

[demyers]

I've had problems with a 5G provider dropping pings with smaller than usual payload sizes, like those sent by dpinger by default. One thing to try is setting your ping payload size to 56 bytes so it looks like a normal ping.

To change this setting in OPNsense go to System: Gateways: Configuration, edit your gateway, switch on "advanced mode", and change Data Length to 56.

[jdrake4]

Awesome!
Thank you so much, that was it!
Just for anyone else reading this i did a little experimenting and found anything < 4 bytes was dropped by my 5g provider. So it just did the default windows ping length of 32