However, all of our IPĪddresses have PTR records that resolve to *. Unable to provide a list of our server IPs. These servers use a number of different IPĪddress ranges, which are also frequently changing. The TeamViewer software makes connections to our master servers This should actually be the most efficient way, if you trust the TeamViewer GmbH's word (for the opposite purposes): BYOD) would involve:įaking or blocking DNS queries for *. Therefore, blocking the connections on network level from any client (incl. by using a transparent proxy, but is totally unnecessary, because the 443 is used before this. Tampering with the data would involve using fake root CA and decrypting the data, and without that it's really hard to detect whether it's TeamViewer traffic or just normal TLS encrypted HTTPS. This is actually the most problematic part, because blocking the default HTTPS port 443 will block all secure web sites.
This is also currently the only port used by Android, Windows Mobile and BlackBerry clients.
TCP/UDP port 5938 is the primary port TeamViewer prefers to use.Just for completeness, TeamViewer uses three different ports in specific order.