I have a load balance configuration with 4 OpenVPN servers with UDP protocol, but it does not connect to the servers, follows log messages


2020/03/12 16:11:15 [error] 6272#0: *97 upstream timed out (110: Connection timed out) while proxying connection, udp client: 3.xxx.xxx.139, server: 0.0.0.0:1194, upstream: "192.168.111.21:1194", bytes from/to client:197/0, bytes from/to upstream:0/197
2020/03/12 16:11:19 [error] 6273#0: *99 upstream timed out (110: Connection timed out) while proxying connection, udp client: 3.xxx.xxx.139, server: 0.0.0.0:1194, upstream: "192.168.111.18:1194", bytes from/to client:197/0, bytes from/to upstream:0/197
2020/03/12 16:11:27 [error] 6273#0: *101 upstream timed out (110: Connection timed out) while proxying connection, udp client: 3.xxx.xxx.139, server: 0.0.0.0:1194, upstream: "192.168.111.19:1194", bytes from/to client:197/0, bytes from/to upstream:0/197
2020/03/12 16:11:43 [error] 6273#0: *103 upstream timed out (110: Connection timed out) while proxying connection, udp client: 3.xxx.xxx.139, server: 0.0.0.0:1194, upstream: "192.168.111.20:1194", bytes from/to client:197/0, bytes from/to upstream:0/197

Config

stream {

include /etc/nginx/stream.d/*.conf;

upstream lb_vpn {

least_conn;
server spo-vpn1.mydomain.local:1194;
server spo-vpn2.mydomain.local:1194;
server spo-vpn3.mydomain.local:1194;
server spo-vpn4.mydomain.local:1194;
}

server {
listen 1194 udp ;
proxy_pass lb_vpn ;
proxy_responses 1 ;
proxy_timeout 2s ;
error_log /var/log/nginx/error-lb_vpn.log ;

}
}