qt - TCP-Program gets no connection from remote pc -

i have written 2 programs talk each other via (qt-)tcp. if both of them running on pc (e.g. using 127.0.0.1 address), going fine. deploy 1 of both programs on pc, no connection back, e.g. connecting program (on port 40000 , 40002) running tcp-servers on other pc works, not other pc on ports 40001 , 40003. because ports closed? tried open them, nmap can not tell me more them. how can find solution?

update: according netstat servers on neccessary ports on local , remote pc listening (for example:

tcp        0      0 0.0.0.0:40002           0.0.0.0:*               listen      off (0.00/0/0) 

), can connect computer remote one, not other way round.

another possibility of error: running dev system in vm nat-connection outside. problem not incoming signal?

it's bind issue, and/or firewall issue.

if listener bound on 127.0.0.1 connections between 2 machines won't work traffic isn't heard on interface. need set bind address 0.0.0.0 (which means any) achieve this.

also, check firewall isn't blocking traffic on these ports if bound interface.

edit example netstat looking 7001 (weblogic admin port) showing listening on various interfaces

$ netstat -nl | grep 7001 tcp6       0      0 192.168.1.149:7001      :::*                    listen      tcp6       0      0 127.0.0.1:7001          :::*                    listen      tcp6       0      0 ::1:7001                :::*                    listen 

edit 2 see you're on nat. traffic originating target not routed own vm. try changing bridged network that's on same range target, if you're using dhcp ip addresses, that'll easiest way vm register ip work.