To configure your Linux firewall you will need to find what firewall you use. Common firewalls include Ufw or iptables.
Here is a list of common firewalls usually built into distro's:
- How-To Geek's Ubuntu/Mint Ufw Guide
- CyberCiti's CentOS/RedHat/Debian IPtables Guide
- Techotopia's Fedora Firewall Guide
- openSUSE's SuSEFirewall2 Guide
In all cases you will need to make sure the port the server is running on, usually 7250, has both UDP and TCP allowed.