DNS queries for Teams/365 domains get dropped / hang

[jamilbk]

• We know that Teams/365 can sometimes use TCP queries
• We will drop these silently

We can log when this happens when we see TCP queries.

[conectado]

We have yet failed to reproduce this issue in our local environment.

Microsoft do lay out what domains, ips and ports should be reachable.

Furthermore, this link explains that Microsoft 365 services make use of DNS to determine your location and optimize latency. However this wouldn't explain the kind of latency the customer is facing.

This link Microsoft recommends split tunneling for teams but-- that's what the customer is doing, only the DNS queries are going through Firezone.

[conectado]

This tool can be super useful.

The "automatically detect location" test fails, this could already be a problem?

[jamilbk]

Latest signs kind of point to it being a TCP DNS issue. Logs:

https://firezonehq.slack.com/archives/C077VKJGQ3W/p1727443520121739

[thomaseizinger]

Should we optimistically close this now that #6944 is merged?