How to capture network traces on Azure App Services (Windows & Linux)

How to capture network traces on Azure App Services (Windows & Linux)

Azure App Service Windows:

• On App Service Page on Azure Portal, select “Diagnose and Solve Problems”: 

• In the search box, type "Collect Network Trace" and select "Collect Network Trace"

   

• Choose the duration and click on Collect Network Trace button: 

• The timer started and the portal will show you the countdown before the trace will automatically stop:

   

How to open the trace file:

• On your Browser, go to Kudo console (https://webappname.scm.azurewebsites.net) -->  Debug console --> CMD , as below:

   

   

A new Zip file will be created, you can download the trace file (cap file) on your machine as below screenshots:

Azure App Service Linux:

Use the tcpdump tool to collect the network trace.

• In most Linux systems, tcpdump tool is pre-installed. If the tool is not installed, install it with the following command:
  • yum install tcpdump
• Determine the name of the active network adapter using any of the commands below.
  • tcpdump -D
  • ip -a
  • ifconfig
  • Collect the network packets and save them in a pcap file

• tcpdump -w /tmp/0001.pcap -i en0
  Where:

  • /tmp is the location where we want to save the capture
  • 0001.pcap is the name of the capture file
  • en0 is the name of the active adapter derived in Step 2
• Reproduce the issue.
• Use Ctrl+C to stop the capture.
• Collect the /tmp/0001.pcap and send it for analysis.