| Protocol | Port(s) | Destination | Purpose | | :--- | :--- | :--- | :--- | | TCP | 443 | *.teamviewer.com | Web login & authentication | | TCP | 5938 | *.teamviewer.com | Primary data channel | | TCP | 80 & 443 | master.teamviewer.com | Fallback & master routing |
In 90% of cases, the culprit is a strict firewall.
Few things are more frustrating in IT support than the dreaded "Connection failed. Partner did not connect to the router." error message.