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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
84,968 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 144.36.179.0/24 | 256 | ARIN |  US | 9th Nov 1990 |
| 144.36.180.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.186.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.190.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.204.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.208.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.212.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.218.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.236.0/24 | 256 | APNIC |  IN | 9th Nov 1990 |
| 144.36.240.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.246.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.64.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.68.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.72.0/23 | 512 | APNIC | IN | 9th Nov 1990 |
| 144.36.74.0/23 | 512 | ARIN | US | 9th Nov 1990 |
| 144.36.76.0/22 | 1k | ARIN | US | 9th Nov 1990 |
| 144.36.80.0/20 | 4.1k | ARIN | US | 9th Nov 1990 |
| 144.36.96.0/21 | 2k | ARIN | US | 9th Nov 1990 |
| 144.48.100.0/22 | 1k | APNIC |  KR | 11th Apr 2016 |
| 144.48.140.0/22 | 1k | APNIC |  IE | 14th Apr 2016 |
| 144.48.156.0/22 | 1k | APNIC |  CN | 14th Apr 2016 |
| 144.48.172.0/22 | 1k | APNIC |  AU | 27th Jun 2019 |
| 144.48.180.0/22 | 1k | APNIC | CN | 18th Apr 2016 |
| 144.48.184.0/22 | 1k | APNIC | CN | 18th Apr 2016 |
| 144.48.200.0/22 | 1k | APNIC |  PH | 19th Apr 2016 |
| 144.48.204.0/22 | 1k | APNIC | CN | 19th Apr 2016 |
| 144.48.208.0/22 | 1k | APNIC | CN | 19th Apr 2016 |
| 144.48.244.0/22 | 1k | APNIC | AU | 21st Apr 2016 |
| 144.48.40.0/22 | 1k | APNIC | KR | 7th Apr 2016 |
| 144.48.44.0/22 | 1k | APNIC | KR | 7th Apr 2016 |
| 144.48.88.0/22 | 1k | APNIC | CN | 11th Apr 2016 |
| 144.5.0.0/16 | 65.5k | ARIN | US | 30th Oct 1990 |
| 144.54.0.0/16 | 65.5k | RIPE NCC |  NL | 13th Nov 1990 |
| 144.61.0.0/16 | 65.5k | ARIN | US | 13th Nov 1990 |
| 144.67.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.68.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.70.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.72.0.0/16 | 65.5k | ARIN | US | 16th Nov 1990 |
| 144.79.10.0/23 | 512 | APNIC | CN | 21st Nov 2025 |
| 144.79.112.0/23 | 512 | APNIC |  SG | 11th Dec 2025 |
| 144.79.126.0/23 | 512 | APNIC | IN | 15th Dec 2025 |
| 144.79.14.0/23 | 512 | APNIC |  VN | 24th Nov 2025 |
| 144.79.148.0/23 | 512 | APNIC | CN | 17th Dec 2025 |
| 144.79.150.0/23 | 512 | APNIC |  PK | 17th Dec 2025 |
| 144.79.2.0/23 | 512 | APNIC |  BD | 21st Nov 2025 |
| 144.79.206.0/23 | 512 | APNIC | IN | 24th Dec 2025 |
| 144.79.208.0/23 | 512 | APNIC | IN | 24th Dec 2025 |
| 144.79.222.0/23 | 512 | APNIC | SG | 29th Dec 2025 |
| 144.79.242.0/23 | 512 | APNIC |  ID | 30th Dec 2025 |
| 144.79.251.0/24 | 256 | APNIC | ID | 31st Dec 2025 |