Route Aggregation Calculator Form
Enter IPv4 CIDR routes using new lines, commas, or semicolons. The page uses a white single-column layout, while the calculator fields use 3, 2, and 1 column responsiveness.
Formula Used
Route aggregation relies on bitwise comparison rather than one algebraic formula. These are the main rules used by the calculator.
- Network address:
Network = IP AND Subnet Mask - Block size:
Addresses = 2^(32 - Prefix) - Exact merge rule: two adjacent routes merge only when they share the same prefix and the same parent block.
- Covering supernet: find the lowest covered address and highest covered address, then count their common leading bits.
- Extra address space:
Wasted Addresses = Supernet Size - Exact Unique Coverage
How to Use This Calculator
- Enter IPv4 routes in CIDR notation, one per line or separated by commas.
- Choose whether you want exact collapsed routes, a covering supernet, or both outputs.
- Select your preferred display order and decide whether binary comparison should appear.
- Click Calculate Aggregation to show results above the form.
- Review the route tables, savings metrics, and graph, then export the report as CSV or PDF.
Example Data Table
| Scenario | Submitted Routes | Exact Collapsed Result | Covering Supernet | Notes |
|---|---|---|---|---|
| Simple pair | 192.168.10.0/24, 192.168.11.0/24 | 192.168.10.0/23 | 192.168.10.0/23 | No extra space is added. |
| Four aligned blocks | 10.10.0.0/24 to 10.10.3.0/24 | 10.10.0.0/22 | 10.10.0.0/22 | All four networks merge exactly. |
| Gapped networks | 172.16.0.0/24, 172.16.2.0/24 | 172.16.0.0/24 and 172.16.2.0/24 | 172.16.0.0/22 | Supernet adds unused addresses between blocks. |
Frequently Asked Questions
1. What does route aggregation mean?
Route aggregation combines multiple smaller routes into fewer larger summaries. It reduces routing table size, simplifies advertisements, and can improve operational clarity when the participating networks are aligned correctly.
2. What is the difference between exact collapse and covering supernet?
Exact collapse preserves only the submitted address space. A covering supernet uses one wider route that covers all submitted networks, but it may also include unused addresses between them.
3. Why does the calculator show wasted addresses?
Wasted addresses appear when the smallest single supernet must include gaps. This helps you see the tradeoff between fewer routing entries and broader advertised coverage.
4. Why was my submitted route changed to a different network value?
If host bits were present, the calculator normalized the route to its true network boundary. For example, 192.168.1.5/24 becomes 192.168.1.0/24 because that is the actual network address.
5. Can I enter overlapping or duplicate routes?
Yes. The calculator removes routes that are fully contained inside broader entries and ignores duplicates during exact collapsing. This keeps the unique coverage calculation practical and clean.
6. Does this version support IPv6 aggregation?
No. This file is focused on IPv4 route aggregation. The same summarization ideas apply to IPv6, but address parsing and presentation would need separate handling.
7. When should I avoid summarizing into one supernet?
Avoid a broad supernet when unused gaps could attract unwanted traffic or violate policy boundaries. In those cases, exact collapsed routes are safer than one oversized summary.
8. What does route savings tell me?
Route savings is the difference between submitted routes and collapsed routes. It shows how many entries you eliminated by normalization, containment removal, and valid aggregation.