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Contact

Email yardfill.helpful594@aleeas.com for a question or reproducible calculator issue. This is an existing shared public forwarding alias used by this free-tool portfolio. It is not a new dedicated mailbox, and the private delivery address is not published here. You can use Cidrspan without contacting anyone.

Describe the numerical discrepancy

Include the address and prefix you entered, which result field differed and what you expected. Prefer an invented address from a documentation range such as 198.51.100.0/24. Include the browser name and whether the issue concerns input validation, a numerical field, the bit diagram, copy or download.

For example, an issue report might say that 198.51.100.206/27 should have canonical lower address 198.51.100.192 and offset 14. This gives enough information to reproduce the arithmetic without exposing a real customer or workplace network. A screenshot can help with a display problem, but inspect it for confidential information before sending.

Understand the model first

The full block count includes all numerical addresses. It is not a usable-host capacity, a reachability result or a recommendation about routing. A /31 or /32 result should therefore be compared with the declared arithmetic model rather than a universal endpoints-subtracted rule. Read the guide and worked examples for the exact scope.

Leading zeroes, dotted input masks, URLs, IPv6, shortened addresses and interior whitespace are deliberately unsupported. These are explicit grammar choices. If a syntax rejection is unexpected, send a safe reproduction showing the exact characters rather than a password, device configuration export or infrastructure map.

Email is a separate action

Sending a message leaves the browser-local calculation boundary and uses email and forwarding providers. There is no promised response time or support contract. A message does not guarantee a change or authorize public posting. The calculator remains free without email, and the privacy page explains clipboard, download and hosting boundaries.