Diagnose HoloLens 2 network issues with Fiddler and Wireshark

[Guest Yannis_Lempidakis]

If network issues are an obstacle to successfully deploying and using HoloLens 2 in your organization, learn how two well-known network diagnostic tools, Fiddler and Wireshark can help you scan, diagnose, and identify problems.

 

Fiddler is a web debugging proxy and is used to troubleshoot HTTP(S) issues. It captures every HTTP request the computer makes and records everything associated with it. Uncovering end-user authentication issues for the HTTPS apps used in your organization drives better productivity and efficiency for your HoloLens 2 use cases.

 

Wireshark is a network protocol analyzer primarily used to inspect TCP/UDP traffic from and to your HoloLens 2 devices. This makes it easy to identify what traffic is crossing your network to your HoloLens 2, how much of it, how frequently, how much latency there is between certain hops, and so forth.

 

In this blog, we’ll go over some examples of when to use these tools, along with installing and configuring them with your HoloLens 2.

 

Fiddler

 

 

For example, let's say you have an authentication issue with a custom line of business (LOB) application. After being installed on your HoloLens 2, the app can't authenticate to the back-end server through HTTPS. To troubleshoot this, you can use Fiddler to capture and decode the HTTPS sessions, enabling discovery of network level-issues.

 

Configure Fiddler to capture HTTP traffic from HoloLens 2

 

 

Prerequisites:

 

• HoloLens 2 devices and your PC must be on the same network
  
• Note the IP address of your PC
  

 

Steps:

 

On your PC, install and start Fiddler. Configure Fiddler to allow remote computers to connect then:

 

1. Go to Fiddler Settings and select Connections.
   
2. Note the listening port for Fiddler (the default is 8866).
   
3. Select Allow remote computers to connect.
   
4. Select Save.
    
   Selecting "Allow remote computers to connect" in Fiddler's connections settings
   

 

On your HoloLens 2, configure Fiddler as the proxy server*:

 

1. Open the Start menu and select Settings.
   
2. Select Network & Internet and then Proxy on the left menu.
   
3. Scroll down to Manual proxy setup and toggle Use a proxy server to On.
   
4. Enter the IP address of the PC where Fiddler is installed.
   
5. Enter the port number noted above (default is 8866).
   
6. Select Save.
   

 

*If your HoloLens 2 devices is running Windows Holographic builds 20279.1006 and later (Insiders and the upcoming release), use the following steps to configure proxy:

 

1. Open the Start menu and go to your Wi-Fi network’s Properties page.
   
2. Scroll down to Proxy.
   
3. Change to Manual Setup.
   
4. Enter the IP address of the PC where Fiddler is installed.
   
5. Enter the port number noted above. (default is 8866).
   
6. Select Apply.
   

Decrypt HTTPS traffic from HoloLens 2

 

 

On your PC, export the Fiddler certificate.

 

1. Go to Fiddler Settings > HTTPS and expand Advanced Settings.
   
2. Click Export Fiddler certificate. The certificate will save to your desktop.
    
   Exporting the root certificate in Fiddler
   
3. Move the certificate to the Downloads folder on your HoloLens 2.
   

 

On your HoloLens 2, import the Fiddler certificate.

 

1. Go to Settings > Update and Security > Certificates.
   
2. Click Install Certificate, browse to the Downloads folder and select the Fiddler certificate.
   
3. Change Store Location to Local Machine.
   
4. Change Certificate Store to root.
   
5. Select Install.
   
6. Confirm the certificate is showing in the list of certificates. If not, repeat the above steps.
   

Inspect HTTP(S) sessions

 

 

On your PC, Fiddler will show the HoloLens 2’s live HTTP(S) sessions. The Inspectors panel in Fiddler can show HTTP(S) request/response in different views - for example, the “Raw” view shows the raw request or response in plain text.

 

The Inspectors panel in Fiddler showing the HoloLens 2 HTTP session

 

Wireshark

 

 

Applications like Dynamics 365 Remote Assist and VPN plug-ins use non-HTTPS traffic. If your HoloLens 2 has any issues with those types of apps, Wireshark can be used to capture and inspect the IP traffic to troubleshoot your internal OS level networking stack.

 

Configure Wireshark to capture network traffic from HoloLens 2

 

 

Prerequisites:

 

• PC must have internet access and support Internet sharing over Wi-Fi.
  

 

Steps:

 

On your PC:

 

1. Install Wireshark.
   
2. In Mobile hotspot settings, turn Share my Internet connection with other devices to On.
    
   Mobile hotspot settings on the Windows 10 PC
   
3. Start Wireshark and capture traffic from the Mobile hotspot interface.
    
   The Capture screen in Wireshark
   

 

On your HoloLens 2, change the Wi-Fi network to the PC’s mobile hotspot. HoloLens 2 IP traffic will now show up in Wireshark.

 

Analyze Wireshark logs

 

 

Wireshark filters can help filtering out the packets of interests. For example, “tcp.stream eq 1” shows the second TCP stream in the log (stream index starts with 0), “ip.addr == 192.168.137.1 && tcp.port == 80” filters out the TCP packets on port 80 with source/destination IP equals 192.168.137.1.

 

An example of the logs produced by Wireshark

 

Conclusion

 

 

After deploying HoloLens 2 to your organization, you may need to capture network traffic for troubleshooting purposes. Both Fiddler and Wireshark will work with the HoloLens 2 to identify and diagnose problems in the HTTP(S) and TCP/UDP levels.

 

Feedback Hub and troubleshooting tips

 

 

HoloLens 2 provides a few methods for users to provide diagnostic logs to Microsoft for investigation. You can use Feedback Hub to submit logs for generic network connectivity issues by submitting your feedback through the “Network & Internet” category. In addition the built-in Settings Troubleshooter can collect detailed network traces for more complex issues. Please refer to Collect and use diagnostic information from HoloLens devices for instructions.

 

Additional resources

 

 

For additional information, please see:

 

• Fiddler
  
• Wireshark
  
• HoloLens documentation
  

 

Continue reading...