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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 205.235.64.0/20 | 4.1k | ARIN |  US | 8th Jun 1995 |
| 205.236.100.0/24 | 256 | ARIN |  CA | 25th Apr 1995 |
| 205.236.102.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.108.0/24 | 256 | ARIN | CA | 7th Sept 1995 |
| 205.236.109.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.115.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.116.0/24 | 256 | ARIN | CA | 28th Aug 1995 |
| 205.236.118.0/24 | 256 | ARIN | CA | 25th Aug 1995 |
| 205.236.119.0/24 | 256 | ARIN | CA | 24th Aug 1995 |
| 205.236.124.0/24 | 256 | ARIN | CA | 24th Aug 1995 |
| 205.236.125.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.128.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.129.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.13.0/24 | 256 | ARIN | CA | 24th Apr 1996 |
| 205.236.130.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.131.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.132.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.140.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.141.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.142.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.145.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.146.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.149.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.152.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.157.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.158.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.16.0/24 | 256 | ARIN | CA | 7th Feb 1996 |
| 205.236.160.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.162.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.164.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.165.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.166.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.169.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.170.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.171.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.173.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.175.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.176.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.178.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.18.0/24 | 256 | ARIN | CA | 5th Feb 1996 |
| 205.236.180.0/24 | 256 | ARIN | CA | 26th Feb 1996 |
| 205.236.181.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.182.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.185.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.186.0/23 | 512 | ARIN | CA | 25th Apr 1995 |
| 205.236.188.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.189.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.19.0/24 | 256 | ARIN | CA | 9th Feb 1996 |
| 205.236.191.0/24 | 256 | ARIN | CA | 25th Apr 1995 |
| 205.236.225.0/24 | 256 | ARIN | CA | 20th Oct 1995 |