tinc and UDP
I have tinc running between my SG-3100 (2.4.5-RELEASE-p1 with tinc 1.0.35_2) and a Fresh Tomato router (2020.5 with tinc 1.1pre17-de7d5a0) over the Internet. The problem: I can't get them to use UDP to transfer data, which is needed to improve throughput.
With Wireshark, I can see the Tomato router periodically send a UDP packet to port 655 of the SG-3100. With tcpdump on the SG-3100, I can see those packets come in, but I don't see any UDP traffic come from tincd on the SG-3100. The tinc logs don't show anything interesting (to my untrained eyes) on either end even at debug level 5. I don't see any blocking of port 655 in the SG-3100 firewall logs. Neither end is using TCPOnly in their configs.