Microsoft 365 network connectivity test tool (preview)

The Microsoft 365 network connectivity test tool is located at https://connectivity.office.com. It is an adjunct tool to the network assessment and network insights information available in the Microsoft 365 admin center under the Health | Connectivity menu.

Connectivity test tool

Note

The network connectivity test tool supports tenants in WW Commercial and Germany but not GCC Moderate, GCC High, DoD or China.

The network insights in the Microsoft 365 Admin Center are based on regular in-product measurements for your Microsoft 365 tenant which are aggregated each day. In comparison, the network insights from the Microsoft 365 network connectivity test are run locally and one time in the tool. Testing that can be done in-product is limited and by running tests local to the user more data can be gathered resulting in deeper insights. Consider then that the network insights in the Microsoft 365 Admin Center will show that there is a networking problem for use of Microsoft 365 at a specific office location. The Microsoft 365 connectivity test can help to identify the root cause of that problem leading to a recommended network performance improvement action.

We recommend that these be used together where networking quality status can be assessed for each office location in the Microsoft 365 Admin Center and more specifics can be found after deployment of testing based on the Microsoft 365 connectivity test.

Important

Network insights, performance recommendations and assessments in the Microsoft 365 Admin Center is currently in preview status, and is only available for Microsoft 365 tenants that have been enrolled in the feature preview program.

What happens at each test step

Office location identification

When you click the run test button we show the running test page and identify the office location. You can type in your location by city, state, and country or you can have it detected from the web browser. If you detect it then we request the latitude and longitude from the web browser and limit the accuracy to 300m by 300m before use. We do this because it is not necessary to identify the location more accurately than the building for network performance.

JavaScript tests

After office location identification we run a TCP latency test in JavaScript and we request data from the service about in-use and recommended Office 365 service front door servers. When these are completed we show them on the map and in the details tab where they can be viewed prior to the next step.

Download the advanced tests client application

Next we start the download of the advanced tests client application. We rely on the user to launch the client application and they must also have .NET Core installed.

There are two parts to the Microsoft 365 network connectivity test; the web site https://connectivity.office.com and a downloadable Windows client application that runs advanced network connectivity tests. Most of the tests require the application to be run. It will populate results back into the web page as it runs.

You will be prompted to download the advanced client test application from the web site after the web browser tests have completed. Open and run the file when prompted.

Advanced tests client application

Start the advanced tests client application

Once the client application starts the web page will update to show this and test data will start to be received to the web page. It updates each time new data is received and you can review the data as it arrives.

Advanced tests completed and test report upload

Once the tests are completed the web page and the advanced tests client will both indicate this and if the user is signed in the test report will be uploaded to the customers tenant.

Sharing your test report

The test report requires sign-in to your Office 365 account. Your administrator selects how you can share your test report.

Sharing your report with your administrator

All test reports while you are signed in are shared with your administrator.

Sharing with your Microsoft account team, support or other personnel

Test reports excluding any personal identification are shared with Microsoft employees. This is enabled by default and can be disabled by your administrator in the Health | Network Connectivity page in the Microsoft 365 Admin Center.

Sharing with other users who sign in to the same Office 365 tenant

You can choose users to share your report with and this is enabled by default. It can also be disabled by your administrator.

Sharing a link to your test results with a user

You can share your test report with anyone by providing access to a ReportID link. This generates a URL that you can send to someone so that they can bring up the test report without signing in. This is disabled by default and must be enabled by your administrator.

Sharing a link to your test results

Network Connectivity Test Results

The results are shown in the Summary and Details tabs. The summary tab shows a map of the detected network perimeter and a comparison of the network assessment to other Office 365 customers nearby. It also allows for sharing of the test report. Here's what the summary results view looks like.

Network connectivity test tool summary results

Here is an example of the details tab output that the tool shows. On the details tab we show a green circle check mark if the result was compared favorably to a threshold. We show a red triangle exclamation point if the result exceeded a threshold indicating a network insight. The following sections describe each of the details tab results rows and explains the thresholds used for network insights.

Network connectivity test tool example test results

Your location information

This section shows test results related to your location.

Your location

The user location is detected from the users web browser, or it can be typed in at the users choice. It is used to identify network distances to specific parts of the enterprise network perimeter. Only the city from this location detection and the distance to other network points are saved in the report.

The user office location is shown on the map view.

Network egress location (the location where your network connects to your ISP)

We identify the network egress IP address on the server side. Location databases are used to look up the approximate location for the network egress. These databases typically have an accuracy of about 90% of IP addresses. If the location looked up from the network egress IP address is not accurate then this would lead to a false result from this test. To validate if this error is occurring for a specific IP address you can use publicly accessible network IP address location web sites to compare to your actual location.

Your distance from the network egress location

We determine the distance from that location to the office location. This is shown as a network insight if the distance is greater than 500 miles (800 kilometers) since that is likely to increase the TCP latency by more than 25ms and may affect user experience.

The network egress location is shown on the map view and connected to the user office location indicating the network backhaul inside of the enterprise WAN.

Implementing local and direct network egress from user office locations to the Internet is recommended for Microsoft 365 network connectivity. Improvements to local and direct egress are the best way to address this network insight.

Proxy server information

We identify proxy server(s) configured on the local machine. We identify if any of these are configured in the network path for optimize category Microsoft 365 network traffic. We identify the distance from the user office location to the proxy servers. The distance is tested first by ICMP ping and if that fails we test with TCP ping and finally if that fails we look up the proxy server IP Address in an IP Address location database. We show a network insight if the proxy server is further than 500 miles (800 kilometers) away from the user office location.

Virtual private network (VPN) you use to connect to your organization

This detects if you are using a VPN to connect to Office 365. A passing result will show if you have no VPN, or if you have a VPN with recommended split tunnel configuration for Office 365.

VPN Split Tunnel

Each optimize category route for Exchange Online, SharePoint Online, and Microsoft Teams is tested to see if it is tunneled on the VPN or not. A split out workload avoids the VPN entirely. A tunneled workload is all sent over the VPN. A selective tunneled workload has some routes sent over the VPN and some split out. A passing result will show if all workloads are split out or selective tunneled.

Customers in your metropolitan area with better performance

The network TCP latency of the user office location to the Exchange Online service front door is compared to other Microsoft 365 customers in the same metro area. A network insight is shown if 10% or more of customers in the same metro area have better performance. This means their users will have better performance in the Microsoft 365 user interface.

This network insight is generated on the basis that all users in a city have access to the same telecommunications infrastructure and the same proximity to Internet circuits and Microsoft's network.

Time to make a DNS request on your network

This shows the DNS server configured on the client machine that ran the tests. It might be a DNS Recursive Resolver server however this is uncommon. It is more likely to be a DNS forwarder server which caches DNS results and forwards any uncached DNS requests to another DNS server.

This is provided for information only and does not contribute to any network insight.

Your distance from and/or time to connect to a DNS recursive resolver

The in-use DNS Recursive Resolver is identified by making a specific DNS request and then asking the DNS Name Server for the IP Address that it received the same request from. This IP Address is the DNS Recursive Resolver and it will be looked up in IP Address location databases to find the location. The distance from the user office location to the DNS Recursive Resolver server location is then calculated. This is shown as a network insight if the distance is greater than 500 miles (800 kilometers).

The location looked up from the network egress IP Address may not be accurate and this would lead to a false result from this test. To validate if this error is occurring for a specific IP Address you can use publicly accessible network IP Address location web sites.

This network insight will specifically impact the selection of the Exchange Online service front door. To address this insight local and direct network egress should be a pre-requisite and then DNS Recursive Resolver should be located close to that network egress.

Exchange Online

This section shows test results related to Exchange Online.

Exchange service front door location

The in-use Exchange service front door is identified in the same way that Outlook does this and we measure the network TCP latency from the user location to it. The TCP latency is shown and the in-use Exchange service front door is compared to the list of best service front doors for the current location. This is shown as a network insight if one of the best Exchange service front door(s) is not in use.

Not using one of the best Exchange service front door(s) could be caused by network backhaul before the corporate network egress in which case we recommend local and direct network egress. It could also be caused by use of a remote DNS recursive resolver server in which case we recommend aligning the DNS recursive resolver server with the network egress.

We calculate a potential improvement in TCP latency (ms) to the Exchange service front door. This is done by looking at the tested user office location network latency and subtracting the network latency from the current location to the closets Exchange service front door. The difference represents the potential opportunity for improvement.

Best Exchange service front door(s) for your location

This lists the best Exchange service front door locations by city for your location.

Service front door recorded in the client DNS

This shows the DNS name and IP Address of the Exchange service front door server that you were directed to. It is provided for information only and there is no associated network insight.

SharePoint Online

This section shows test results related to SharePoint Online and OneDrive.

The service front door location

The in-use SharePoint service front door is identified in the same way that the OneDrive client does and we measure the network TCP latency from the user office location to it.

Download speed

We measure the download speed for a 15Mb file from the SharePoint service front door. The result is shown in megabytes per second to indicate what size file in megabytes can be downloaded from SharePoint or OneDrive in one second. The number should be similar to one tenth of the minimum circuit bandwidth in megabits per second. For example if you have a 100mbps internet connection, you may expect 10 megabytes per second (10MBps).

Buffer bloat

During the 15Mb download we measure the TCP latency to the SharePoint service front door. This is the latency under load and it is compared to the latency when not under load. The increase in latency when under load is often attributable to consumer network device buffers being loaded (or bloated). A network insight is shown for any bloat of 1,000 or more.

Service front door recorded in the client DNS

This shows the DNS name and IP Address of the SharePoint service front door server that you were directed to. It is provided for information only and there is no associated network insight.

Microsoft Teams

This section shows test results related to Microsoft Teams.

Media connectivity (audio, video, and application sharing)

This tests for UDP connectivity to the Microsoft Teams service front door. If this is blocked then Microsoft Teams may still work using TCP, but audio and video will be impaired. Read more about these UDP network measurements which also apply to Microsoft Teams at Media Quality and Network Connectivity Performance in Skype for Business Online

Packet loss

Shows the UDP packet loss measured in a 10 second test audio call from the client to the Microsoft Teams service front door. This should be lower than 1.00% for a pass.

Latency

Shows the measured UDP latency, which should be lower than 100ms.

Jitter

Shows the measured UDP jitter, which should be lower than 30ms.

Connectivity

We test for HTTP connectivity from the user office location to all of the required Microsoft 365 network endpoints. These are published at https://aka.ms/o365ip. A network insight is shown for any required network endpoints which cannot be connected to.

Connectivity may be blocked by a proxy server, a firewall, or another network security device on the enterprise network perimeter. Connectivity to TCP port 80 is tested with an HTTP request and connectivity to TCP port 443 is tested with an HTTPS request. If there is no response the FQDN is marked as a failure. If there is an HTTP response code 407 the FQDN is marked as a failure. If there is an HTTP response code 403 then we check the Server attribute of the response and if it appears to be a proxy server we mark this as a failure. You can simulate the tests we perform with the Windows command line tool curl.exe.

We test the SSL certificate at each required Microsoft 365 network endpoint that is in the optimize or allow category as defined at https://aka.ms/o365ip. If any tests do not find a Microsoft SSL certificate, then the encrypted network connected must have been intercepted by an intermediary network device. A network insight is shown on any intercepted encrypted network endpoints.

Where an SSL certificate is found that isn't provided by Microsoft, we show the FQDN for the test and the in-use SSL certificate owner. This SSL certificate owner may be a proxy server vendor, or it may be an enterprise self-signed certificate.

Network path

This section shows the results of an ICMP traceroute to the Exchange Online service front door, the SharePoint Online service front door, and the Microsoft Teams service front door. It is provided for information only and there is no associated network insight. There are three traceroutes provided. A traceroute to outlook.office365.com, a traceroute to the customers SharePoint front end or to microsoft.sharepoint.com if one was not provided, and a traceroute to world.tr.teams.microsoft.com.

Connectivity reports

When you are signed in you can review previous reports that you have run. You can also share them or delete them from the list.

Reports

Network health status

This shows any significant health issues with Microsoft's global network which might impact Microsoft 365 customers.

Network health status

FAQ

Here are answers to some of our frequently asked questions.

Is this tool released and supported by Microsoft?

It is currently a preview and we plan to provide updates regularly until we reach general availability release status with support from Microsoft. Please provide feedback to help us improve. We are planning to publish a more detailed Office 365 Network Onboarding guide as part of this tool which is customized for the organization by its test results.

What is required to run the advanced test client?

The advanced test client requires .NET Core 3.1 Desktop Runtime. If you run the advanced test client without that installed you will be directed to the .NET Core 3.1 installer page. Be sure to install the Desktop Runtime and not the SDK, or the ASP.NET Core Runtime which are higher up on the page. Administrator permissions on the machine is required to install .NET Core.

What is Microsoft 365 service front door?

The Microsoft 365 service front door is an entry point on Microsoft's global network where Office clients and services terminate their network connection. For an optimal network connection to Microsoft 365, it is recommended that your network connection is terminated into the closest Microsoft 365 front door in your city or metro.

Note: Microsoft 365 service front door has no direct relationship to the Azure Front Door Service product available in the Azure marketplace.

What is the best Microsoft 365 service front door?

A best Microsoft 365 service front door (formerly known as an optimal service front door) is one that is closest to your network egress, generally in your city or metro area. Use the Microsoft 365 network performance tool to determine location of your in-use Microsoft 365 service front door and the best service front door(s). If the tool determines your in-use front door is one of the best ones, then you should expect great connectivity into Microsoft's global network.

What is an internet egress location?

The internet egress Location is the location where your network traffic exits your enterprise network and connects to the Internet. This is also identified as the location where you have a Network Address Translation (NAT) device and usually where you connect with an Internet Service Provider (ISP). If you see a long distance between your location and your internet egress location, then this may identify a significant WAN backhaul.

Network connectivity in the Microsoft 365 Admin Center (preview)

Microsoft 365 network performance insights (preview)

Microsoft 365 network assessment (preview)

Microsoft 365 Network Connectivity Location Services (preview)