Calculator Form
Example Data Table
| Input Networks | Why They Merge | Summarized Result |
|---|---|---|
| 192.168.0.0/24 and 192.168.1.0/24 | Adjacent /24 blocks align on a /23 boundary. | 192.168.0.0/23 |
| 10.0.0.0/24 and 10.0.1.0/24 | Their ranges combine into one exact /23 block. | 10.0.0.0/23 |
| 172.16.0.0/25 and 172.16.0.128/25 | Two half blocks rebuild one complete /24 route. | 172.16.0.0/24 |
| 192.168.10.12/24 | Host bits normalize to the proper network boundary. | 192.168.10.0/24 |
Formula Used
Network summarization works by comparing address blocks in binary. Each summarized route keeps the shared prefix bits and replaces varying suffix bits with zeros.
Network address: IP address AND subnet mask.
Broadcast address: Network address + block size - 1.
Block size: 232 - prefix.
Summarization rule: Adjacent or overlapping ranges can merge when their combined range fits exact CIDR boundaries without leaving address gaps.
Covering supernet: Find the common leading bits between the lowest and highest included addresses, then build the smallest single route that covers both ends.
How to Use This Calculator
- Enter IPv4 CIDR routes, dotted-mask routes, or single IPv4 addresses.
- Choose whether to reject misaligned entries or normalize them.
- Keep adjacent merging enabled for aggressive route reduction.
- Use duplicate removal to simplify repeated source data.
- Submit the form to generate analysis and summarized routes.
- Review the input table, final output, graph, and optional supernet.
- Export the summarized results as CSV or PDF.
Frequently Asked Questions
1. What does network summarization do?
It combines overlapping or adjacent IPv4 routes into fewer CIDR blocks. That reduces routing table size and makes address planning easier to review.
2. Can I enter dotted subnet masks?
Yes. The calculator accepts formats like 192.168.1.0/255.255.255.0. It converts the dotted mask into the matching prefix before calculating results.
3. What happens to host addresses?
A single IPv4 address is treated as a /32 route. A host inside a larger entered block can also normalize to the correct network boundary if strict rejection is disabled.
4. Why is strict alignment useful?
Strict alignment helps catch bad inputs. It rejects entries where the stated route does not begin at the actual network boundary for its prefix.
5. Does merging adjacent blocks add extra addresses?
No. Adjacent blocks only merge when they fit an exact CIDR boundary. The summarized output still represents the same covered range without unnecessary gaps.
6. What is the difference between summary routes and a covering supernet?
Summary routes describe the exact minimal CIDR answer. A covering supernet is one larger route that covers everything, even if it includes extra address space.
7. Why show total addresses and usable hosts?
These values help compare route sizes quickly. They also make it easier to understand how much address space each summarized block represents.
8. Can I export the final results?
Yes. The page includes CSV export for spreadsheet work and PDF export for sharing summarized outputs, tables, and route analysis with others.