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Jack_Chen1780's avatar
Jack_Chen1780
Brass Contributor
Feb 15, 2023

Microsoft Teams Network Assessment Tool always fail

Hi , I am trying to use this Microsoft tool to verify Teams Network connectivity from my office : 

https://www.microsoft.com/en-us/download/details.aspx?id=103017

 

But it always showed error:

 

"

Starting Service Connectivity Check:
Please ensure your firewall allows connections to the following domains: *.cc.skype.com
Please check if IP 52.114.201.11 is reachable using HTTP

Service verifications failed."

 

It's always the same message, but the IP could change to other 52.114.201.xx IP.

 

The problem is I have no problem to connect to those IP's port 80 and 443. 

 

I captured the traffic to 52.114.201.0/24 (attached the capture ) and the communication looks normal:

There was TLS handshake and then there are some data transferred via TLS1.2.

 

The server certificate is *.flightproxy.teams.microsoft.com signed by Microsoft ( and I traced DNS and found the real DNS is latm-noam.flightproxy.teams.microsoft.com ).

I can access https://latm-noam.flightproxy.teams.microsoft.com/ and confirm the certificate is trusted and signed by "Microsoft RSA TLS CA 02".

 

So I have no idea why the assess tool is complaining 52.114.201.11 is not reachable?

 

Any help is appreciated.

 

 

 

 

 

 

 

 

 

 

 

 

  • Jack_Chen1780's avatar
    Jack_Chen1780
    Brass Contributor
    here is the command line output:

    C:\Program Files (x86)\Microsoft Teams Network Assessment Tool>NetworkAssessmentTool.exe
    Microsoft Teams - Network Assessment Tool

    Starting Relay Connectivity Check:
    UDP, PseudoTLS, FullTLS, HTTPS connectivity will be checked to this relay (VIP) FQDN: worldaz.tr.teams.microsoft.com
    If user wants to check connectivity to a particular relay (VIP) IP, please specify in NetworkAssessment.exe.config.

    Connectivity check source port range: 50000 - 50019

    Relay : 52.115.86.6 is the relay load balancer (VIP)

    Starting Service Connectivity Check:
    Relay : 52.115.86.6 is reachable using Protocol UDP and Port 3478
    Relay : 52.115.86.6 is QOS (Media Priority) enabled
    Relay : 52.115.86.6 is the relay load balancer (VIP)
    Relay : 52.115.86.6 is reachable using Protocol PseudoTLS and Port 443
    Relay : 52.115.86.6 is the relay load balancer (VIP)
    Relay : 52.115.86.6 is reachable using Protocol FullTLS and Port 443
    Relay : 52.115.86.6 is the relay load balancer (VIP)
    Relay : 52.115.86.6 is reachable using Protocol HTTPS and Port 443
    Relay : 52.115.86.228 is the actual relay instance (DIP)
    Relay : 52.115.86.228 is reachable using Protocol UDP and Port 3478
    Relay : 52.115.86.228 is the actual relay instance (DIP)
    Relay : 52.115.86.228 is reachable using Protocol UDP and Port 3479
    Relay : 52.115.86.228 is the actual relay instance (DIP)
    Relay : 52.115.86.228 is reachable using Protocol UDP and Port 3480
    Relay : 52.115.86.228 is the actual relay instance (DIP)
    Relay : 52.115.86.228 is reachable using Protocol UDP and Port 3481

    Relay connectivity and Qos (Media Priority) check is successful for all relays.
    Please ensure your firewall allows connections to the following domains: *.cc.skype.com
    Please check if IP 52.114.201.15 is reachable using HTTP

    Service verifications failed.

    More information on Office 365 URLs and IP address ranges can be found at following page.
    https://support.office.com/en-us/article/Office-365-URLs-and-IP-address-ranges-8548a211-3fe7-47cb-abb1-355ea5aa88a2

    Service connectivity result has been written to: C:\Users\XXX\AppData\Local\Microsoft Teams Network Assessment Tool\202302150916482595_service_connectivity_check_results.txt
    • Jack_Chen1780's avatar
      Jack_Chen1780
      Brass Contributor
      run the same test from a Azure VM with full Internet access, and got same error.

      "Relay connectivity and Qos (Media Priority) check is successful for all relays.
      Please ensure your firewall allows connections to the following domains: *.cc.skype.com
      Please check if IP 52.114.201.11 is reachable using HTTP

      Service verifications failed."

      Maybe the tool is outdated?

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