What ports does TeamViewer use?

TeamViewer does not need additional firewall configuration to connect to other computers. And in the vast majority of cases, the program will work properly if web browsing is allowed.

But in some situations, such as in a corporate environment with strict security policies, the firewall may be configured to block all unknown outgoing connections. In this case, you will have to configure the firewall to allow TeamViewer to connect through it.

Port usage sequence in TeamViewer

TCP / UDP - port 5938. This is the main port for the operation of the program. The firewall on your PC or local network must allow packets to pass through this port.

TCP is port 443. If TeamViewer cannot connect via port 5938, it will try to connect via TCP 443. Furthermore, TCP 443 is used by some TeamViewer user modules as well as a number of other processes, for example to check for updates to the Program.

TCP is port 80. If TeamViewer cannot connect through port 5938 or 443, it will try to work through TCP 80. The connection speed through this port is slower and less reliable because it is used by other programs such as browsers, and also since this port does not connect automatically in case of connection failure. For these reasons, TCP 80 is only used as a last resort.

To enforce a strict security policy, simply block all incoming connections and allow outgoing connections through port 5938, regardless of the destination IP address.

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