Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in Singapore
15 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 151.146.0.0/16 | 65.5k | ARIN |  SG | 26th Feb 1991 |
| 199.103.68.0/24 | 256 | ARIN | SG | 25th Jun 1994 |
| 23.156.44.0/24 | 256 | ARIN | SG | 9th Apr 2026 |
| 23.158.132.0/24 | 256 | ARIN | SG | 18th May 2026 |
| 2602:f3bc::/40 | 16.8M × /64 | ARIN | SG | 15th May 2026 |
| 2602:f402::/40 | 16.8M × /64 | ARIN | SG | 7th Apr 2026 |
| 2602:f548::/40 | 16.8M × /64 | ARIN | SG | 26th Sept 2025 |
| 2602:f741::/36 | 268M × /64 | ARIN | SG | 9th Jan 2025 |
| 2602:f74f::/36 | 268M × /64 | ARIN | SG | 30th Dec 2024 |
| 2602:f832::/40 | 16.8M × /64 | ARIN | SG | 21st Aug 2024 |
| 2602:f834::/40 | 16.8M × /64 | ARIN | SG | 21st Aug 2024 |
| 2602:f8fe::/40 | 16.8M × /64 | ARIN | SG | 3rd May 2024 |
| 2602:f902::/40 | 16.8M × /64 | ARIN | SG | 2nd May 2024 |
| 2602:fbfc::/36 | 268M × /64 | ARIN | SG | 6th Dec 2021 |
| 2602:fc51::/36 | 268M × /64 | ARIN | SG | 26th Jul 2021 |