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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,960 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 31.99.152.0/24 | 256 | ARIN |  US | 18th May 2026 |
| 31.99.153.0/24 | 256 | RIPE NCC |  GB | 25th Nov 2010 |
| 31.99.154.0/23 | 512 | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.156.0/22 | 1k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.160.0/19 | 8.2k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.192.0/21 | 2k | RIPE NCC |  DE | 25th Nov 2010 |
| 31.99.208.0/20 | 4.1k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.224.0/19 | 8.2k | RIPE NCC | GB | 25th Nov 2010 |
| 31.99.64.0/18 | 16.4k | RIPE NCC | GB | 25th Nov 2010 |
| 32.144.0.0/12 | 1M | ARIN | US | 25th Sept 2023 |
| 32.240.0.0/15 | 131k | ARIN | US | 23rd Jun 2023 |
| 34.3.2.0/24 | 256 | ARIN | US | 9th May 2022 |
| 35.128.216.0/21 | 2k | ARIN | US | 1st Apr 1994 |
| 35.128.224.0/19 | 8.2k | ARIN | US | 1st Apr 1994 |
| 35.18.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.26.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.28.0.0/14 | 262k | ARIN | US | 8th Feb 2024 |
| 35.34.64.0/20 | 4.1k | ARIN | US | 1st Apr 1994 |
| 35.48.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.52.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.56.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 35.60.0.0/15 | 131k | ARIN | US | 8th Feb 2024 |
| 36.0.0.0/22 | 1k | APNIC |  CN | 14th Apr 2011 |
| 36.0.128.0/17 | 32.8k | APNIC | CN | 9th Mar 2011 |
| 36.0.16.0/20 | 4.1k | APNIC | CN | 12th Apr 2011 |
| 36.0.32.0/19 | 8.2k | APNIC | CN | 12th Apr 2011 |
| 36.0.4.0/22 | 1k | APNIC |  NP | 16th Mar 2011 |
| 36.0.64.0/18 | 16.4k | APNIC | CN | 11th Mar 2011 |
| 36.0.8.0/21 | 2k | APNIC | CN | 28th Jan 2011 |
| 36.2.112.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.128.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.224.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.2.32.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.254.0.0/16 | 65.5k | APNIC | CN | 31st Jan 2011 |
| 36.255.120.0/22 | 1k | APNIC |  JP | 18th Feb 2016 |
| 36.255.124.0/22 | 1k | APNIC |  SG | 18th Feb 2016 |
| 36.255.148.0/22 | 1k | RIPE NCC | GB | 19th Feb 2016 |
| 36.255.160.0/22 | 1k | APNIC | JP | 22nd Feb 2016 |
| 36.255.172.0/22 | 1k | APNIC | CN | 22nd Feb 2016 |
| 36.255.176.0/22 | 1k | APNIC | CN | 22nd Feb 2016 |
| 36.255.196.0/22 | 1k | APNIC |  IN | 23rd Feb 2016 |
| 36.255.36.0/22 | 1k | APNIC | JP | 11th Feb 2016 |
| 36.255.92.0/22 | 1k | RIPE NCC |  HR | 16th Feb 2016 |
| 36.3.160.0/19 | 8.2k | APNIC | SG | 1st Feb 2011 |
| 36.3.80.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 36.37.0.0/19 | 8.2k | APNIC | CN | 12th Apr 2011 |
| 36.37.36.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 36.37.38.0/24 | 256 | APNIC |  AU | 11th Aug 2011 |
| 36.37.39.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 36.37.40.0/21 | 2k | APNIC | CN | 12th Apr 2011 |