#upstream stream_backend {
#    server backend1.example.com:12345 weight=5;
#    server backend2.example.com:12345 max_fails=2 fail_timeout=30s;
#    server backend3.example.com:12345 max_conns=3;
#}
#
#upstream dns_servers {
#    least_conn;
#    server 192.168.136.130:53;
#    server 192.168.136.131:53;
#    server 192.168.136.132:53;
#}
#
#server {
#    listen        12345;
#    proxy_pass    stream_backend;
#    proxy_timeout 3s;
#    proxy_connect_timeout 1s;
#}
#
#server {
#    listen     53 udp;
#    proxy_pass dns_servers;
#}