Open Control Panel -> System and Security -> Windows Firewall -> Advanced Settings
Open "Inbound rules" on the left pane, click "New rule" on the right pane
In a new rule you can specify the required port, protocol, profile rule applied to and assign the rule name. Please see this document for ports and protocols used by Sync IT.
You'll need root privileges to add changes to your iptables. Please use the following command to add rules to iptables:
iptables -I INPUT -p tcp -dport <destinantion_port> -j ACCEPT
This command will add a new rule to the top of your INPUT chain to allow incoming TCP packets to the specified port. You can check here which ports are used by Sync IT.
If you want to make your iptables permanent so as not to get them reset every reboot, use the
iptables-save > <your_filename>
command to save the current iptables status to a file, then load iptables on boot using the
command. You can place the command for loading rules to the /etc/rc.local file or any other script which executes upon boot.