Which ports are used by TeamViewer? In general, TeamViewer will always
work if surfing on the Internet is possible. Hence, no firewall
configuration is required. As an alternative to port 80 HTTP, port 443
HTTPs is also being checked. In addition, it is also possible to open
only port 5938 TCP on the outgoing side. Data traffic should then be
able to pass through on this port without any problems.