It sounds to me you have a fundamental problem if this is affecting multiple o/s

Perhaps have a think about:

1) power supplies ok?
2) sd cards ok?
3) device ping responses ok?
4) firewall rules / port path to devices ok?

Surely there must be a simple answer to this question..

Facing the same issue here. TCP traffic does not go through IPSec VPN (Strongswan 5.3.5+) with Ubuntu or Debian (kernel 4.x) on NanoPi NEO/NEO2 while UDP and ICMP is fine. Tried both VTI tunnel and "normal" connection types, same configuration works perfectly fine on Ubuntu 16.04/Intel. D...

I'm failing to get this fully working on a NEO2 with a tunnel brought up to an AWS hosted Algo VPN server. It does partially work in so far as I've verified that ICMP ping traffic from the NEO2 is 100% successful. In addition my remote AWS hosted VPN is verified as 100% working fine with other stron...

There doesn't seem to be much info regarding which image to go for. http://wiki.friendlyarm.com/wiki/index.php/NanoPi_NEO2#Make_an_Installation_TF_Card suggests flashing the ubuntu image by default but there's also a debian image which at the time of writing is slightly more recent than ubuntu. So q...