Added Flow Trace section header

Author: sujamiya

articles/firewall/monitor-firewall-reference.md

@@ -119,6 +119,8 @@ There are a few ways to verify the update was successful, but you can navigate t
 
 To create a diagnostic setting and enable Resource Specific Table, see [Create diagnostic settings in Azure Monitor](/azure/azure-monitor/essentials/create-diagnostic-settings).
 
+## Flow Trace
+
 The firewall logs show traffic through the firewall in the first attempt of a TCP connection, known as the *SYN* packet. However, such an entry doesn't show the full journey of the packet in the TCP handshake. As a result, it's difficult to troubleshoot if a packet is dropped, or asymmetric routing occurred. The Azure Firewall Flow Trace Log addresses this concern.
 
 > [!TIP]