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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,584 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 5.104.226.0/24 | 256 | RIPE NCC |  NL | 2nd Jul 2012 |
| 5.104.227.0/24 | 256 | RIPE NCC | NL | 2nd Jul 2012 |
| 5.104.228.0/24 | 256 | RIPE NCC | NL | 2nd Jul 2012 |
| 5.104.229.0/24 | 256 | RIPE NCC | NL | 2nd Jul 2012 |
| 5.104.230.0/23 | 512 | RIPE NCC | NL | 2nd Jul 2012 |
| 5.104.64.0/21 | 2k | RIPE NCC |  US | 28th Jun 2012 |
| 5.104.76.0/22 | 1k | RIPE NCC |  DE | 11th Jun 2018 |
| 5.133.116.0/22 | 1k | RIPE NCC | DE | 9th Nov 2018 |
| 5.133.80.0/22 | 1k | RIPE NCC |  GB | 9th Nov 2018 |
| 5.144.152.0/24 | 256 | RIPE NCC | GB | 12th Jul 2012 |
| 5.144.154.0/23 | 512 | RIPE NCC | GB | 12th Jul 2012 |
| 5.149.96.0/20 | 4.1k | RIPE NCC |  IQ | 16th Jul 2012 |
| 5.150.152.0/22 | 1k | RIPE NCC |  GI | 18th Jul 2012 |
| 5.152.132.0/22 | 1k | RIPE NCC |  CZ | 18th Jul 2012 |
| 5.152.150.0/23 | 512 | RIPE NCC |  SE | 18th Jul 2012 |
| 5.152.168.0/21 | 2k | RIPE NCC |  ES | 19th Jul 2012 |
| 5.152.176.0/21 | 2k | RIPE NCC | DE | 19th Jul 2012 |
| 5.153.0.0/18 | 16.4k | RIPE NCC | NL | 19th Jul 2012 |
| 5.154.186.0/24 | 256 | RIPE NCC |  CH | 19th Jul 2012 |
| 5.154.188.0/23 | 512 | RIPE NCC |  IM | 19th Jul 2012 |
| 5.154.225.0/24 | 256 | RIPE NCC |  RS | 19th Jul 2012 |
| 5.154.232.0/24 | 256 | RIPE NCC | GB | 19th Jul 2012 |
| 5.154.234.0/23 | 512 | RIPE NCC | ES | 19th Jul 2012 |
| 5.154.239.0/24 | 256 | RIPE NCC |  RO | 19th Jul 2012 |
| 5.159.193.0/24 | 256 | RIPE NCC | CH | 26th Jan 2026 |
| 5.159.194.0/24 | 256 | RIPE NCC | CH | 26th Jan 2026 |
| 5.159.240.0/21 | 2k | RIPE NCC | ES | 30th Jul 2012 |
| 5.159.80.0/20 | 4.1k | RIPE NCC | DE | 27th Jul 2012 |
| 5.172.100.0/22 | 1k | RIPE NCC |  IT | 30th Jul 2012 |
| 5.172.104.0/21 | 2k | RIPE NCC | IT | 30th Jul 2012 |
| 5.172.112.0/20 | 4.1k | RIPE NCC | IT | 30th Jul 2012 |
| 5.178.126.0/23 | 512 | RIPE NCC | IT | 7th Aug 2012 |
| 5.179.96.0/20 | 4.1k | ARIN | US | 4th Dec 2024 |
| 5.180.156.0/22 | 1k | RIPE NCC | DE | 29th Mar 2019 |
| 5.180.160.0/22 | 1k | RIPE NCC | NL | 29th Mar 2019 |
| 5.180.176.0/24 | 256 | RIPE NCC |  UA | 19th May 2021 |
| 5.180.88.0/22 | 1k | RIPE NCC | DE | 29th Mar 2019 |
| 5.181.13.0/24 | 256 | RIPE NCC | CH | 1st Apr 2019 |
| 5.181.148.0/22 | 1k | RIPE NCC |  AT | 2nd Apr 2019 |
| 5.181.17.0/24 | 256 | RIPE NCC |  TR | 1st Apr 2019 |
| 5.181.220.0/22 | 1k | RIPE NCC | ES | 3rd Apr 2019 |
| 5.181.32.0/22 | 1k | RIPE NCC | DE | 1st Apr 2019 |
| 5.182.104.0/23 | 512 | RIPE NCC |  DK | 5th Apr 2019 |
| 5.182.246.0/24 | 256 | RIPE NCC | TR | 9th Apr 2019 |
| 5.182.61.0/24 | 256 | RIPE NCC | CH | 21st Jan 2026 |
| 5.182.63.0/24 | 256 | RIPE NCC | DE | 21st Jan 2026 |
| 5.182.76.0/22 | 1k | RIPE NCC | GB | 5th Apr 2019 |
| 5.183.112.0/22 | 1k | RIPE NCC | GB | 10th Apr 2019 |
| 5.183.150.0/24 | 256 | RIPE NCC | ES | 11th Apr 2019 |
| 5.183.160.0/24 | 256 | RIPE NCC | TR | 14th Jan 2025 |