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v1.0.6

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@MadAreYou MadAreYou released this 08 Mar 18:35
· 3 commits to dev since this release
v1.0.6
612f209

ntchk v1.0.6 - Subnet & CIDR Calculator

Release Date: March 7, 2026

📥 Download & Install

📦 Release Assets (2 files required)

File Description
ntchk-v1.0.6-Portable.zip Main application package
ntchk-v1.0.6-Portable.zip.sha256 SHA256 checksum for verification

⬇️ Download both files from the Assets section below

🔒 Security First

⚠️ Always verify the checksum before running! See the File Verification section below.

🚀 Quick Installation

  1. Download both files from GitHub releases
  2. Verify the download using the .sha256 file
  3. Extract ZIP to any folder (USB drive, network share, local drive - all supported)
  4. Run ntchk.exe (recommended) or ntchk.bat
  5. Done! No installation, no registry changes, fully portable

🎯 What's New

🔢 Subnet & CIDR Calculator — New Tab

A full subnet and CIDR calculation tool has been added as a new "Subnet Calc" tab, located between Diagnostics and Settings.

Subnet Calculator

Live classful subnet math. Select Network Class (A / B / C), enter an IP address, pick a subnet mask — all fields update instantly:

Field Description
First Octet Range Valid first-octet range for the selected class
Hex IP Address Dotted hexadecimal representation of the IP
Wildcard Mask Inverse mask for ACL use
Subnet Bits Number of bits borrowed from the host portion
Mask Bits Total prefix length
Maximum Subnets Number of subnets available for the class
Hosts per Subnet Usable host addresses per subnet
Host Address Range First to last usable host address
Subnet ID Network address
Broadcast Address Directed broadcast address
Subnet Bitmap Bit-level visual breakdown (class-id · network · host bits)

CIDR Calculator

Live classless CIDR math. Enter an IP address and select a mask length (1–32) — all fields update instantly:

Field Description
CIDR Netmask Subnet mask in dotted-quad notation
Wildcard Mask Inverse mask for ACL use
Maximum Subnets Total number of addresses in the block (2^host-bits)
Maximum Addresses Usable host addresses (Maximum Subnets − 2)
CIDR Network Network address of the block
Net: CIDR Notation Network address with prefix (e.g. 192.168.1.0/24)
CIDR Address Range First to last usable host address

All fields recalculate on every keystroke or dropdown change — no button required.

🛠️ Technical Notes

  • New src/SubnetCalc.ps1 module — self-contained, no external dependencies, pure PowerShell arithmetic
  • Integer arithmetic uses [Math]::Floor throughout to prevent PowerShell banker's rounding from corrupting octet values (e.g. 255.996… rounding up to 256)
  • Class selection tracked via $Script:SubnetClass to prevent WPF nullable bool timing issues in deeply nested event handlers
  • Light and Dark mode fully supported — uses existing dynamic resource brushes

🔄 Compatibility

  • All existing features unchanged (Speed Test, Network Info, Diagnostics, Settings)
  • Settings and configuration backward compatible
  • No new dependencies

🔒 File Verification

After downloading, verify the ZIP integrity before running:

# Run in PowerShell in the folder where you downloaded the files
$hash = Get-FileHash "ntchk-v1.0.6-Portable.zip" -Algorithm SHA256
$expected = Get-Content "ntchk-v1.0.6-Portable.zip.sha256"
if ($hash.Hash -eq $expected.Trim()) { "✅ MATCH - Safe to extract" } else { "❌ MISMATCH - Do not run!" }
Assets 4
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