I have installed Trader WorkStation by Interactive Brokers. However, the program does not run, with assistance from support I found that the firewall is the problem.
The servers (several primary and backup servers) listen on port 4000 and 4001 (in case of SSL connection). The site recommends the following command for testing:
telnet zdc1.ibllc.com 4000
If I try to run that, I get
Trying 126.96.36.199... telnet: connect to address 188.8.131.52: Connection timed out
I already tried to activate the port:
$ firewall-cmd --list-ports 1025-65535/udp 1025-65535/tcp $ firewall-cmd --zone=public --add-port=4000/tcp --permanent success $ firewall-cmd --reload success
The testing is still negative.
Connection timed out.
How can I open the port? It would be ideal to restrict the access only to a few servers that are mentioned on the site. I have Fedora 27. Thank you.
EDIT (Solved): Thanks to @mark-plotnick. The problem was in the settings of the router - when I connect elsewhere, the connection works. As I will move in a few days, it's not necessary to open the ports in the router.