The connection speed over this port is slower and less reliable than ports 5938 or 443, due to the additional overhead it uses, and there is no automatic reconnection if the connection is temporarily lost. Port 443 is also used for a few other things, including TeamViewer update checks.TCP Port 80If TeamViewer can’t connect over port 5938 or 443, then it will try on TCP port 80. through Group Policy, then you need to ensure that port 443 is open on the computers to which you’re deploying. Your firewall should allow this at a minimum.TCP Port 443If TeamViewer can’t connect over port 5938, it will next try to connect over TCP port 443.However, our mobile apps running on iOS and Windows Mobile don't use port 443.📌Note: port 443 is also used by our custom modules which are created in the Management Console. TeamViewer makes outbound connections to the internet, which are usually not blocked by firewalls.However, in some situations, for example in a corporate environment with strict security policies, a firewall might be set up to block all unknown outbound connections, and in this case, you will need to configure the firewall to allow TeamViewer to connect out through it.TeamViewer's PortsThese are the ports that TeamViewer needs to use.TCP/UDP Port 5938TeamViewer prefers to make outbound TCP and UDP connections over port 5938 – this is the primary port it uses, and TeamViewer performs best using this port. In the vast majority of cases, TeamViewer will always work if surfing on the internet is possible. GeneralThis article applies to all users in all licenses.TeamViewer is designed to connect easily to remote computers without any special firewall configurations being necessary. Ports used by TeamViewer - TeamViewer Support

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