# Overview

LLMS index: [llms.txt](/v1.1.0.0/llms.txt)

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DNSServer.DebugLogParser is a PowerShell module that transforms Windows DNS Server debug log files into structured, analyzable CSV data for security analysis, performance monitoring, troubleshooting, and compliance reporting.

## What is a DNS debug log?

DNS debug logging is a feature of Windows DNS Server that records detailed information about DNS operations. When enabled, the DNS Server writes log entries to a text file (typically `dns.log`) in the DNS Server’s directory.

Each log entry contains up to 16 fields including:

- Date and time of the query
- Protocol used (UDP or TCP)
- Direction (Send or Receive)
- Client IP address
- Query type (A, AAAA, MX, PTR, etc.)
- Domain name queried
- Response code (NOERROR, NXDOMAIN, etc.)
- Query flags and options
- IP address in response (for successful queries)
- Port numbers and additional technical details

## Why parse DNS debug logs?

DNS logs are critical for:

### Troubleshooting

- Diagnose name resolution failures
- Identify misconfigured clients or applications
- Track down the source of problematic queries
- Verify proper DNS configuration and zone transfers

### Performance monitoring

- Identify high-volume query sources
- Analyze query types and patterns to optimize DNS infrastructure
- Detect configuration issues causing excessive queries
- Track response times and success rates
- Monitor DNS server load and capacity

### Security analysis

- Detect DNS tunneling and data exfiltration attempts
- Identify domains associated with malware and command-and-control servers
- Track suspicious query patterns that may indicate compromised systems
- Monitor for DNS amplification attacks
- Investigate security incidents and trace attacker activity

### Compliance and auditing

- Meet regulatory requirements for logging and retention
- Document network activity for audit trails
- Generate reports for management and compliance officers
- Demonstrate due diligence in security monitoring

## How the module works (high level)

The module is optimized for large files and processes DNS debug logs into structured CSV output. It supports multi-line records (for example PACKET detail blocks and indented continuation lines) so that event/diagnostic messages and packet details stay attached to the correct record.

Key capabilities:

- Parses the native DNS debug log fields and produces a consistent CSV layout
- Handles multiple DNS Server versions (2012 R2 through 2025)
- Supports both PowerShell Desktop (5.1+) and Core (7.x)
- Processes files of any size (tested with 100MB+ files)
- Validates log file headers to ensure data integrity
- Generates optional statistical summaries
- Supports batch processing via PowerShell pipeline
- Optionally compresses output files to save disk space
- Can automatically remove source files after successful processing
- Culture-aware date parsing for international DNS server logs
- Culture-aware date formatting for international output requirements

## Licensing and support

The module is released under the MIT License. Community support is available through GitHub Issues.

- GitHub repository: https://github.com/AndiBellstedt/DNSServer.DebugLogParser
- PowerShell Gallery: https://www.powershellgallery.com/packages/DNSServer.DebugLogParser