Forum Discussion
Network connectivity test TCP Connection results unreliable
My team has spent the last 2 business days trying to get the https://connectivity.office.com/ TCP connection test to complete successfully to appease the Microsoft Unified Support Team. They don't w...
Consider this:
- Whitelist Microsoft 365 Endpoints
Ensure your firewall, proxy, or endpoint security software allows traffic to all Microsoft 365 URLs and IPs.
- Disable SSL/TLS Inspection
If you’re using any kind of SSL inspection (even at home via antivirus), disable it for Microsoft endpoints. These include:
- *.microsoft.com
- *.office365.com
- *.digicert.com
- *.symcb.com
- Use a Clean Test Environment
Try running the test from a clean Windows install with no antivirus, VPN, or proxy settings. Use a wired connection if possible.
- Check DNS Resolution
Use a reliable DNS provider like Google (8.8.8.8) or Cloudflare (1.1.1.1) to ensure proper resolution of OCSP endpoints.
- Run the Test Authenticated
Sign in to the test site with your Microsoft 365 account. This can improve accuracy and provide tenant-specific diagnostics.