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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 157.96.38.0/24 | 256 | RIPE NCC |  GB | 7th Apr 2004 |
| 157.96.39.0/24 | 256 | RIPE NCC |  SE | 7th Apr 2004 |
| 157.96.41.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.43.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.44.0/23 | 512 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.46.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.56.0/22 | 1k | ARIN |  US | 30th Mar 2020 |
| 157.96.60.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.62.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.65.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.66.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.68.0/22 | 1k | ARIN | US | 30th Mar 2020 |
| 157.96.79.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.8.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.81.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.88.0/24 | 256 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.90.0/23 | 512 | RIPE NCC | GB | 7th Apr 2004 |
| 157.96.92.0/23 | 512 | RIPE NCC | SE | 7th Apr 2004 |
| 157.96.94.0/23 | 512 | RIPE NCC | GB | 7th Apr 2004 |
| 157.96.96.0/20 | 4.1k | RIPE NCC | SE | 7th Apr 2004 |
| 157.97.148.0/22 | 1k | RIPE NCC |  CH | 13th Jul 1995 |
| 157.97.164.0/22 | 1k | RIPE NCC |  DE | 13th Jul 1995 |
| 157.97.72.0/22 | 1k | RIPE NCC | DE | 13th Jul 1995 |
| 158.106.240.0/21 | 2k | ARIN |  CA | 20th May 2015 |
| 158.113.0.0/16 | 65.5k | ARIN | US | 26th Feb 1992 |
| 158.115.0.0/17 | 32.8k | ARIN | US | 26th Feb 1992 |
| 158.118.0.0/16 | 65.5k | ARIN | US | 27th Feb 1992 |
| 158.119.0.0/16 | 65.5k | RIPE NCC | GB | 28th Feb 1992 |
| 158.120.224.0/20 | 4.1k | APNIC |  AU | 28th Feb 1992 |
| 158.120.78.0/24 | 256 | ARIN | US | 14th Feb 2023 |
| 158.120.79.0/24 | 256 | RIPE NCC | US | 28th Feb 1992 |
| 158.124.0.0/16 | 65.5k | RIPE NCC | GB | 2nd Mar 1992 |
| 158.128.0.0/16 | 65.5k | ARIN | CA | 30th Mar 1992 |
| 158.131.0.0/16 | 65.5k | RIPE NCC |  FI | 6th Mar 1992 |
| 158.133.0.0/16 | 65.5k | RIPE NCC | CH | 6th Mar 1992 |
| 158.134.0.0/16 | 65.5k | ARIN | US | 9th Mar 1992 |
| 158.137.0.0/16 | 65.5k | ARIN | US | 6th Mar 1992 |
| 158.139.0.0/16 | 65.5k | ARIN | US | 10th Mar 1992 |
| 158.140.8.0/21 | 2k | ARIN | US | 1st Jun 2016 |
| 158.146.160.0/19 | 8.2k | ARIN | US | 12th Mar 1992 |
| 158.146.192.0/18 | 16.4k | ARIN | US | 12th Mar 1992 |
| 158.152.0.0/16 | 65.5k | RIPE NCC | GB | 13th Mar 1992 |
| 158.159.0.0/16 | 65.5k | ARIN | US | 17th Mar 1992 |
| 158.163.0.0/16 | 65.5k | ARIN | CA | 18th Mar 1992 |
| 158.164.0.0/16 | 65.5k | ARIN | US | 18th Mar 1992 |
| 158.171.0.0/16 | 65.5k | ARIN | US | 23rd Mar 1992 |
| 158.178.0.0/17 | 32.8k | RIPE NCC | US | 24th Mar 1992 |
| 158.178.254.0/23 | 512 | RIPE NCC | GB | 24th Mar 1992 |
| 158.179.0.0/24 | 256 | RIPE NCC | GB | 24th Mar 1992 |
| 158.179.1.0/24 | 256 | RIPE NCC | SE | 24th Mar 1992 |