IPTools is a free educational project for network administrators, students, and people learning computer networking. Dominik Mirek owns and runs it as a private individual. IPTools is the project name. Materials are credited to the project; its operator handles contact and correction reports.
Core principles
- Calculations run locally in the browser.
- The site has no advertising or tracking analytics.
- Guides identify the standards and official sources behind their content.
- The interface works on desktop and mobile and supports keyboard use.
How materials are prepared and checked
Text, examples, and code are prepared with assistance from AI tools. Checks include comparing technical claims with primary sources—RFCs, IANA registries, and vendor documentation—and verifying calculations programmatically. This process helps identify errors but does not guarantee their absence.
Calculator tests cover subnet boundaries, /31 and /32 exceptions, VLSM, DHCP exclusions, and transfer units, among other cases. Guide examples receive additional numerical checks. For example, IPv6 /56-to-/64 subnetting was checked by comparing 128-bit address values and independently with Python’s ipaddress library, including all 256 blocks. Cisco lab results are stated as expectations; they are not presented as a transcript from real hardware.
The source-check date records when cited documents and registries were checked. An article’s update date describes a change to the material. Neither date represents certification or an independent expert review, and we do not assign such credentials or roles to the project owner.
Corrections and contact
Report an error to kontakt@iptools.pl. Include the page URL, relevant passage or inputs, actual result, and the reason for your proposed correction, ideally with a primary-source link. Reproduction steps help us add a regression check. One correction made on 12 September 2026 concerns /56-to-/64 subnetting: the subnet number changes the fourth IPv6 group while the first 56 bits stay fixed.
Who is it for?
It serves people learning IP addressing and practitioners checking a subnet, VLSM plan, DHCP pool, or conversion. Start with the IPv4 guide or open the subnet calculator.
Using the results
The tools and guides are educational aids. Before changing a production environment, verify the result against the documentation for the systems and devices you use.