run Keyhotee,console print,
433718ms th_a       application.cpp:106           connect_loop         ] unspecified
Broken pipe
    {"message":"Broken pipe"}
    asio  asio.cpp:28 read_write_handler
error connecting to 162.243.67.4:9876
    {"ep":"162.243.67.4:9876"}
    th_a  connection.cpp:194 connect
unable to connect to 162.243.67.4:9876
    {"ep":"162.243.67.4:9876"}
    th_a  server.cpp:257 connect_to

ping is ok
$ping 162.243.67.4
PING 162.243.67.4 (162.243.67.4) 56(84) bytes of data.
64 bytes from 162.243.67.4: icmp_req=1 ttl=47 time=251 ms
64 bytes from 162.243.67.4: icmp_req=2 ttl=47 time=253 ms
64 bytes from 162.243.67.4: icmp_req=3 ttl=47 time=257 ms
64 bytes from 162.243.67.4: icmp_req=4 ttl=47 time=247 ms
telnet test is refused
$ telnet 162.243.67.4 9876
Trying 162.243.67.4...
telnet: Unable to connect to remote host: Connection refused