can not run on centos 7

Dear You,
your program run on widow environment is OK . Client A and B connection successfully
But when I run with Censtos environment , there is a false on Client :
_Error: listen EADDRINUSE : address already in use xx.xx.xx.xx :56830
 at Server.setupListenhandle [as _isten2] (net.js:1280:14)_
please tell me way to debug

Thansk you