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Network Analysis Tools for SharePoint Online

By Nagendra Jayaram • September 15, 2025 • 12 min read

About Network Analysis for SharePoint

Network traffic analysis is crucial for debugging SharePoint Online issues, understanding API calls, and monitoring authentication flows. Whether you're troubleshooting performance problems, authentication failures, or API errors, capturing and analyzing network traffic provides invaluable insights into the root cause of issues.

Download Fiddler

Official Download: Telerik Fiddler Classic or Fiddler Everywhere

Choose Fiddler Classic for Windows or Fiddler Everywhere for cross-platform support.

Tool Options: Fiddler vs Browser Developer Tools

Method 1: Fiddler (Advanced Analysis)

Best for: Deep HTTP analysis, HTTPS decryption, advanced filtering, and professional debugging scenarios.

Installation and Setup

  1. Download Fiddler: Get Fiddler Classic (Windows) or Fiddler Everywhere (cross-platform)
  2. Install Application: Run installer with administrator privileges
  3. Configure HTTPS Decryption: Tools > Options > HTTPS tab
  4. Enable HTTPS Capture: Check "Capture HTTPS CONNECTs" and "Decrypt HTTPS traffic"
  5. Install Certificate: Click "Install Certificate" and trust the Fiddler root certificate
  6. Restart Browser: Close and reopen browsers to pick up proxy settings

SharePoint-Specific Configuration

# Fiddler Filters for SharePoint Online Host: *.sharepoint.com Host: *.microsoftonline.com Host: *.office.com Host: *.windows.net # Filter by Request Methods Method: POST # API calls, form submissions Method: GET # Page loads, resource requests Method: PUT # Updates and modifications Method: DELETE # Deletion operations # Filter by Response Codes Status: 4** # Client errors (401, 403, 404, etc.) Status: 5** # Server errors (500, 503, etc.) Status: 200 # Successful requests

Advanced Fiddler Features

  • AutoResponder: Mock API responses for testing scenarios
  • Composer: Craft and send custom HTTP requests
  • Timeline View: Visualize request timing and dependencies
  • Request Comparison: Compare similar requests to identify differences
  • Script Debugging: Custom FiddlerScript for automated analysis

Method 2: Browser Developer Tools (Quick Analysis)

Best for: Quick debugging, basic network analysis, and scenarios where Fiddler installation isn't possible.

Step-by-Step Process

  1. Open Developer Tools: Press F12 in Chrome, Edge, or Firefox
  2. Navigate to Network Tab: Click on the "Network" tab in developer tools
  3. Clear Existing Entries: Click the clear button (🚫) to remove old network entries
  4. Enable Recording: Ensure recording is enabled (red circle should be visible)
  5. Reproduce Issue: Perform the action that causes the SharePoint problem
  6. Analyze Results: Look for failed requests (red entries) and examine response details

Browser DevTools Analysis Features

  • Request Headers: Examine authentication tokens, user agents, and custom headers
  • Response Analysis: View response bodies, headers, and status codes
  • Timing Information: Analyze request timing breakdown (DNS, SSL, response time)
  • Initiator Tracking: See which script or action triggered each request
  • Resource Filtering: Filter by domain, file type, or response status
# Useful Browser DevTools Filters # Filter by domain sharepoint.com microsoftonline.com # Filter by status codes status-code:4* # Client errors status-code:5* # Server errors status-code:200 # Successful requests # Filter by request methods method:POST method:GET # Filter by resource type xhr # AJAX requests fetch # Fetch API calls doc # Documents/pages

SharePoint Correlation ID: Critical for Support

Understanding Correlation IDs

Every SharePoint Online request generates a unique Correlation ID that Microsoft support uses to trace issues in their logs. This ID is essential for effective support interactions and should always be captured when reporting problems.

Where to Find Correlation IDs

  • Error Pages: Displayed prominently in SharePoint error messages
  • HTTP Headers: Found in response headers as "SPRequestGuid" or "request-id"
  • Browser Console: Sometimes logged in JavaScript console errors
  • ULS Logs: Recorded in SharePoint's Unified Logging System

Capturing Correlation IDs

# In Fiddler - Look for these headers in responses: SPRequestGuid: 12345678-1234-1234-1234-123456789012 request-id: 87654321-4321-4321-4321-210987654321 X-SharePointHealthScore: 1 # In Browser DevTools - Check Response Headers: 1. Select failed request 2. Click Headers tab 3. Look in Response Headers section 4. Find SPRequestGuid or request-id value

Common SharePoint HTTP Response Codes

Success Codes (2xx)

200 OK - Request successful, content returned 201 Created - Resource created successfully (new item/document) 202 Accepted - Request accepted for processing (async operations) 204 No Content - Successful operation with no content (DELETE, some PUTs)

Client Error Codes (4xx) - SharePoint Specific

400 Bad Request - Invalid request syntax or malformed data 401 Unauthorized - Authentication required or failed 403 Forbidden - User lacks permissions for the resource 404 Not Found - Site, list, item, or resource doesn't exist 409 Conflict - Resource already exists or version conflict 412 Precondition Failed - If-Match header doesn't match current ETag 413 Payload Too Large - File upload exceeds size limits (100GB max) 415 Unsupported Media - File type blocked by admin policy 429 Too Many Requests - Rate limiting or throttling applied

Server Error Codes (5xx) - SharePoint Specific

500 Internal Server Error - General server error, check Correlation ID 503 Service Unavailable - Service temporarily unavailable or throttled 504 Gateway Timeout - Request timeout (large operations, slow networks) 507 Insufficient Storage - Site storage quota exceeded

Practical Analysis Scenarios

Authentication and Login Issues

Authentication Flow Analysis

Monitor these key URLs during authentication problems:

# OAuth Authentication Flow URLs https://login.microsoftonline.com/*/oauth2/authorize https://login.microsoftonline.com/*/oauth2/token https://*.sharepoint.com/_forms/default.aspx https://*.sharepoint.com/_trust/ # Common Authentication Response Codes 302 - Normal redirect during OAuth flow 401 - Authentication failed or expired 403 - User account disabled or conditional access blocked

API Call Debugging

# SharePoint REST API Endpoints to Monitor /_api/web/lists # List operations /_api/web/currentuser # Current user context /_api/search/query # Search operations /_vti_bin/client.svc # Client object model calls /_layouts/15/basepage.aspx # Page rendering # Key Headers to Examine Accept: application/json;odata=verbose Content-Type: application/json;odata=verbose Authorization: Bearer [token] X-RequestDigest: [form digest value] If-Match: [etag for updates]

Performance Analysis

Best Practices for Network Analysis

Data Collection

  • Clear Cache First: Start with clean browser cache to avoid misleading results
  • Reproduce Consistently: Ensure the issue can be reproduced reliably
  • Capture Complete Flows: Start recording before the issue occurs
  • Document Context: Note user actions, timing, and environmental factors
  • Save Sessions: Export Fiddler sessions or save HAR files for later analysis

Analysis Methodology

  • Start with Errors: Focus on failed requests (4xx, 5xx status codes) first
  • Check Authentication: Verify OAuth flows and token validity
  • Examine Timing: Identify performance bottlenecks and slow requests
  • Validate Headers: Ensure required headers are present and correct
  • Compare Working vs Broken: Analyze differences between successful and failed scenarios

Security and Privacy

  • Sensitive Data Handling: Be cautious with authentication tokens and personal data
  • Certificate Trust: Only install Fiddler certificates on development machines
  • Session Sharing: Sanitize captures before sharing with others
  • Compliance Considerations: Follow organizational policies for network monitoring

Troubleshooting Common Network Issues

Fiddler Not Capturing HTTPS Traffic

  1. Verify HTTPS decryption is enabled in Fiddler options
  2. Check that Fiddler certificate is installed and trusted
  3. Restart browser after enabling HTTPS capture
  4. Verify proxy settings aren't being overridden
  5. Try disabling antivirus HTTPS scanning temporarily

Browser DevTools Missing Network Data

  1. Ensure Network tab is open before reproducing the issue
  2. Check that recording is enabled (red circle visible)
  3. Clear network log and try again
  4. Disable browser extensions that might interfere
  5. Try in incognito/private mode to rule out cache issues

SharePoint-Specific Network Issues

Integration with Other SharePoint Tools

PowerShell Correlation

# Use network analysis to validate PowerShell operations # Example: Monitor API calls during PowerShell execution # In Fiddler/DevTools, look for these patterns during PowerShell: POST /_vti_bin/client.svc/ProcessQuery GET /_api/web/lists/getbytitle('ListName') POST /_api/web/lists/getbytitle('ListName')/items # Correlation with PowerShell error messages: # Match Correlation IDs from network traffic with PowerShell exceptions

Search Query Tool Validation

About the Author: Nagendra Jayaram is a Microsoft Sr Technical Advisor with 18+ years of enterprise experience specializing in SharePoint Online troubleshooting and network analysis.