MTU for WAN on AX3000 and verizon 5g home

[lepa71]

I'm wondering if I should change MTU on my AX3000 for WAN from 1500 to 1400
Here is my setup I have Verizon 5 cube and I put it into passthrough more and it works after I had to change "DHCP query frequency" to Continuous mode based on Verizon tech support.
Here is the reason. It seems that I get a disconnect once a day when verizon is trying to change IP. I ran some ping with 1400 and I get replies but when I ping with 1500 I get "Packet needs to be fragmented but DF set."
So my question is.
Should I change WAN MTU setting to 1400?

Also. Do I need to change other settings like "Extend the TTL value" and "Spoof LAN TTL value" to yes or not?

Thanks

 

[drinkingbird]

I'm wondering if I should change MTU on my AX3000 for WAN from 1500 to 1400
Here is my setup I have Verizon 5 cube and I put it into passthrough more and it works after I had to change "DHCP query frequency" to Continuous mode based on Verizon tech support.
Here is the reason. It seems that I get a disconnect once a day when verizon is trying to change IP. I ran some ping with 1400 and I get replies but when I ping with 1500 I get "Packet needs to be fragmented but DF set."
So my question is.
Should I change WAN MTU setting to 1400?

Also. Do I need to change other settings like "Extend the TTL value" and "Spoof LAN TTL value" to yes or not?

Thanks

According to another poster in here Verizon 5G should be 1428 for WAN MTU. You can test this by doing your ping with 1427, 1428, and 1429. The largest one that succeeds is what you want to use.

You shouldn't need to mess with TTL and not sure why you'd need continuous mode for DHCP, sounds like DHCP isn't working correctly so that setting may not be right.

 

[lepa71]

Does o

According to another poster in here Verizon 5G should be 1428 for WAN MTU. You can test this by doing your ping with 1427, 1428, and 1429. The largest one that succeeds is what you want to use.

You shouldn't need to mess with TTL and not sure why you'd need continuous mode for DHCP, sounds like DHCP isn't working correctly so that setting may not be right.

Does it matter what IP I'm pining? I was doing my external IP

 

[drinkingbird]

Does o

Does it matter what IP I'm pining? I was doing my external IP

Use something out on the internet like google DNS 8.8.8.8. Leave your WAN MTU at 1500 for the test then adjust it down to whatever you find (I suspect it will be 1428). After it finishes saving, reboot the router.