Analyzing Microsoft Forefront UAG (Unified Access Gateway) logs effectively with the UAG Trace Analyser is the premier way to parse heavy, binary-format ETL (Event Trace Log) files into human-readable data. Because native UAG tracing outputs raw, high-volume debugging telemetry, a structured parsing approach using the Trace Analyser tool is mandatory for isolating complex authentication, DirectAccess, or reverse proxy application publication errors. Core Components of UAG Tracing
Before analyzing logs, you must understand how UAG telemetry is structured:
Binary ETL Files: UAG generates Event Trace Log (.etl) files. These are highly efficient for the operating system to record but cannot be read directly with text editors.
Trace Format (TMF) Files: These are the translation dictionaries. Microsoft distributes specific Forefront UAG Tracing Symbols containing the .tmf files required to convert binary blobs into plaintext metadata. Step-by-Step Workflow for Effective Analysis 1. Enable and Capture the Trace
Do not leave UAG tracing running indefinitely, as it quickly consumes disk space and degrades performance.
Open the built-in UAG Trace Configuration Utility (UagTraceCfg.exe) on the UAG server.
Select the specific components you need to troubleshoot (e.g., SSTP, DirectAccess, WebProxy, or Auth).
Click Start Tracing, reproduce the user error immediately, and click Stop Tracing to bound your log sizes. 2. Convert and Load with UAG Trace Analyser
The UAG Trace Analyser acts as a graphical wrapper around the underlying command-line tool tracefmt.exe. Launch UAG Trace Analyser.
Point the tool’s template path to your downloaded folder of UAG TMF files.
Import the newly captured .etl log file. The utility automatically decompresses and decodes the GUID strings into readable functions and descriptions. 3. Apply Strategic Filters
A single 10-second trace can yield hundreds of thousands of lines. Use the tool’s built-in filtering syntax to isolate the noise:
Filter by Thread ID (TID): UAG processes each user request inside a unique thread. Find the line where your user’s specific username or IP address first appears, grab that TID, and filter exclusively for it. This presents the entire session chronologically.
Filter by Component: If you suspect an external authentication issue, isolate the log strictly to the ActiveDirectory or RADIUS functional providers.
Filter by Severity: Toggle off Verbose and Information tags to bubble up Error and Warning entries instantly. Key Areas to Watch During Analysis Troubleshooting Scenario Primary Components to Filter What to Look For User Sign-In Failures Auth, ActiveDirectory, RADIUS
Look for Kerberos errors, bad password rejections, or timed-out domain controllers. Application Access Denied WebProxy, WhlFilter
Watch for URL filtering blocks, missing authorization groups, or strict policy restrictions. DirectAccess Connectivity DA, IPsec, SSTP
Isolate infrastructure tunnel connection drops and digital certificate validation failures. Pro-Tips for Advanced Analysis
Synchronize Client and Server Traces: For tricky reverse-proxy or endpoint compliance bugs, run a client-side trace simultaneously. Load both files into separate tabs in the Trace Analyser and match the timestamps to see exactly where the client’s handshake request deviates from the server’s response.
Cross-Reference with the System Event Log: UAG is intentionally designed to forward major alert failures (like repeated failed application logins) directly to the Windows System Event Log. If your trace cuts off abruptly, look at the Event Viewer around that exact millisecond mark to see if an underlying Windows service or driver crashed. Forefront Unified Access Gateway (UAG) Tracing Symbols
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