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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,493 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.115.124.0/23 | 512 | ARIN |  US | 30th Sept 1994 |
| 204.115.136.0/21 | 2k | ARIN | US | 4th Oct 1994 |
| 204.115.148.0/23 | 512 | ARIN | US | 4th Oct 1994 |
| 204.115.152.0/21 | 2k | ARIN | US | 6th Oct 1994 |
| 204.115.160.0/21 | 2k | ARIN | US | 7th Oct 1994 |
| 204.115.206.0/23 | 512 | ARIN | US | 7th Mar 2011 |
| 204.115.208.0/21 | 2k | ARIN | US | 24th Oct 1994 |
| 204.115.22.0/23 | 512 | ARIN | US | 21st Jun 2019 |
| 204.115.232.0/21 | 2k | ARIN | US | 26th Oct 1994 |
| 204.115.24.0/21 | 2k | ARIN | US | 22nd Sept 1994 |
| 204.115.240.0/21 | 2k | ARIN | US | 26th Oct 1994 |
| 204.115.248.0/22 | 1k | ARIN | US | 26th Oct 1994 |
| 204.115.252.0/23 | 512 | ARIN | US | 19th Aug 2026 |
| 204.115.32.0/20 | 4.1k | ARIN | US | 8th Aug 1994 |
| 204.115.48.0/21 | 2k | ARIN | US | 8th Aug 1994 |
| 204.115.56.0/22 | 1k | ARIN | US | 8th Aug 1994 |
| 204.115.60.0/23 | 512 | ARIN | US | 8th Aug 1994 |
| 204.115.72.0/21 | 2k | ARIN | US | 27th Sept 1994 |
| 204.115.8.0/22 | 1k | ARIN | US | 19th Sept 1994 |
| 204.115.87.0/24 | 256 | ARIN | US | 17th Apr 2012 |
| 204.115.88.0/21 | 2k | ARIN | US | 27th Sept 1994 |
| 204.115.96.0/22 | 1k | ARIN | US | 28th Sept 1994 |
| 204.12.128.0/20 | 4.1k | AFRINIC |  ZA | 13th Dec 1994 |
| 204.122.0.0/21 | 2k | ARIN | US | 22nd Aug 1994 |
| 204.122.17.0/24 | 256 | ARIN | US | 15th Nov 2023 |
| 204.122.32.0/19 | 8.2k | ARIN | US | 25th Aug 1994 |
| 204.124.10.0/24 | 256 | ARIN | US | 4th Oct 1994 |
| 204.124.108.0/22 | 1k | ARIN | US | 19th Oct 1994 |
| 204.124.112.0/23 | 512 | ARIN | US | 19th Oct 1994 |
| 204.124.114.0/24 | 256 | ARIN | US | 19th Oct 1994 |
| 204.124.115.0/24 | 256 | ARIN | US | 8th Jul 2026 |
| 204.124.124.0/22 | 1k | ARIN | US | 24th Oct 1994 |
| 204.124.148.0/22 | 1k | ARIN | US | 8th Nov 1994 |
| 204.124.16.0/23 | 512 | ARIN | US | 5th Oct 1994 |
| 204.124.164.0/23 | 512 | ARIN | US | 14th Nov 1994 |
| 204.124.176.0/22 | 1k | ARIN | US | 21st Nov 1994 |
| 204.124.18.0/24 | 256 | ARIN | US | 5th Oct 1994 |
| 204.124.188.0/23 | 512 | ARIN | US | 28th Nov 1994 |
| 204.124.190.0/24 | 256 | ARIN | US | 28th Nov 1994 |
| 204.124.196.0/22 | 1k | ARIN | US | 12th Dec 1994 |
| 204.124.200.0/23 | 512 | ARIN | US | 15th Dec 1994 |
| 204.124.202.0/24 | 256 | ARIN | US | 15th Dec 1994 |
| 204.124.203.0/24 | 256 | ARIN | US | 1st Jul 2020 |
| 204.124.204.0/22 | 1k | ARIN | US | 27th Dec 1994 |
| 204.124.212.0/22 | 1k | ARIN | US | 27th Dec 1994 |
| 204.124.228.0/22 | 1k | ARIN | US | 29th Dec 1994 |
| 204.124.24.0/22 | 1k | ARIN | US | 6th Oct 1994 |
| 204.124.240.0/22 | 1k | ARIN | US | 10th Jan 1995 |
| 204.124.248.0/23 | 512 | ARIN | US | 14th Jan 1995 |
| 204.124.250.0/24 | 256 | ARIN | US | 14th Jan 1995 |