sendto(udp): Invalid argument

[o-alquimista]

Server side (192.168.1.106), OpenBSD 7.4, arm64:

# udptunnel -s -v 0.0.0.0:4096 127.0.0.1:51820

Client side (192.168.1.151), Linux, glibc, amd64:

# udptunnel -v 0.0.0.0:51820 192.168.1.106:4096

The server keeps dropping the client. See server logs below.

Received a TCP connection from 192.168.1.151:58656
sendto(udp): Invalid argument
Received a TCP connection from 192.168.1.151:60566
sendto(udp): Invalid argument
Received a TCP connection from 192.168.1.151:46066
sendto(udp): Invalid argument