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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
Browse by registry
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Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,356 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.220.225.0/24 | 256 | RIPE NCC |  GB | 30th Oct 2018 |
| 205.220.226.0/24 | 256 | RIPE NCC | GB | 30th Oct 2018 |
| 205.223.128.0/20 | 4.1k | ARIN |  US | 31st May 1995 |
| 205.223.32.0/20 | 4.1k | ARIN | US | 22nd Jun 2026 |
| 205.223.48.0/20 | 4.1k | ARIN | US | 28th Apr 1995 |
| 205.223.64.0/20 | 4.1k | ARIN | US | 2nd May 1995 |
| 205.223.80.0/20 | 4.1k | ARIN | US | 5th May 1995 |
| 205.233.1.0/24 | 256 | ARIN |  CA | 3rd Oct 1995 |
| 205.233.106.0/24 | 256 | ARIN | CA | 2nd Oct 1995 |
| 205.233.107.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.112.0/24 | 256 | ARIN | CA | 8th Sept 1995 |
| 205.233.113.0/24 | 256 | ARIN | CA | 8th Sept 1995 |
| 205.233.114.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.115.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.116.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.117.0/24 | 256 | ARIN | CA | 8th Sept 1995 |
| 205.233.120.0/24 | 256 | ARIN | CA | 15th Sept 1995 |
| 205.233.122.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.123.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.126.0/23 | 512 | ARIN | US | 26th Apr 2024 |
| 205.233.136.0/23 | 512 | ARIN |  NL | 25th Apr 1995 |
| 205.233.138.0/24 | 256 | ARIN | CA | 14th Dec 1993 |
| 205.233.144.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.146.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.147.0/24 | 256 | ARIN | US | 26th Sept 1996 |
| 205.233.148.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.149.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.154.0/24 | 256 | ARIN | CA | 3rd Aug 1995 |
| 205.233.156.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.158.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.16.0/24 | 256 | ARIN | CA | 18th Oct 1995 |
| 205.233.176.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.177.0/24 | 256 | ARIN | CA | 25th Aug 1995 |
| 205.233.178.0/24 | 256 | ARIN | CA | 25th Aug 1995 |
| 205.233.179.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.180.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.182.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.233.184.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.185.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.188.0/22 | 1k | ARIN | CA | 25th Apr 1995 |
| 205.233.192.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.193.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.194.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.195.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.196.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.197.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.198.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.20.0/23 | 512 | ARIN | CA | 6th Dec 1995 |
| 205.233.200.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.233.202.0/24 | 256 | ARIN | CA | 25th Apr 1995 |