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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,041 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 163.227.80.0/23 | 512 | APNIC |  CN | 16th Apr 2025 |
| 163.227.82.0/23 | 512 | APNIC |  HK | 16th Apr 2025 |
| 163.227.94.0/24 | 256 | APNIC |  ID | 17th Apr 2025 |
| 163.231.0.0/16 | 65.5k | ARIN |  US | 25th Aug 1992 |
| 163.241.0.0/16 | 65.5k | ARIN | US | 17th Sept 1992 |
| 163.242.0.0/16 | 65.5k | RIPE NCC |  DE | 1st Sept 1993 |
| 163.243.0.0/16 | 65.5k | ARIN | US | 25th Sept 1992 |
| 163.245.32.0/19 | 8.2k | ARIN | US | 28th Sept 1992 |
| 163.245.64.0/18 | 16.4k | ARIN | US | 28th Sept 1992 |
| 163.250.0.0/16 | 65.5k | LACNIC |  CL | 8th Oct 1992 |
| 163.254.0.0/16 | 65.5k | ARIN | US | 23rd Oct 1992 |
| 163.33.0.0/16 | 65.5k | ARIN | US | 6th Jul 1992 |
| 163.35.0.0/16 | 65.5k | ARIN | US | 6th Jul 1992 |
| 163.36.0.0/14 | 262k | ARIN | US | 6th Jul 1992 |
| 163.47.124.0/22 | 1k | APNIC |  AU | 29th May 2014 |
| 163.47.152.0/22 | 1k | APNIC |  IN | 30th May 2014 |
| 163.47.18.0/24 | 256 | APNIC | AU | 2nd Jun 2014 |
| 163.47.183.0/24 | 256 | ARIN | US | 17th Mar 2020 |
| 163.47.19.0/24 | 256 | APNIC |  JP | 24th Jul 1992 |
| 163.47.196.0/22 | 1k | APNIC | AU | 30th May 2014 |
| 163.47.216.0/22 | 1k | APNIC | AU | 30th May 2014 |
| 163.47.22.0/24 | 256 | APNIC | ID | 22nd Jan 2025 |
| 163.47.23.0/24 | 256 | APNIC | JP | 24th Jul 1992 |
| 163.47.24.0/24 | 256 | APNIC | JP | 24th Jul 1992 |
| 163.47.29.0/24 | 256 | APNIC | JP | 24th Jul 1992 |
| 163.47.47.0/24 | 256 | APNIC | AU | 13th Jun 2014 |
| 163.47.60.0/22 | 1k | APNIC | AU | 28th May 2014 |
| 163.50.0.0/16 | 65.5k | APNIC | JP | 24th Jul 1992 |
| 163.52.0.0/23 | 512 | APNIC |  MM | 13th Aug 2026 |
| 163.52.10.0/23 | 512 | APNIC |  BD | 18th Aug 2026 |
| 163.52.12.0/24 | 256 | APNIC | ID | 18th Aug 2026 |
| 163.52.13.0/24 | 256 | APNIC |  PH | 18th Aug 2026 |
| 163.52.14.0/23 | 512 | APNIC |  VN | 18th Aug 2026 |
| 163.52.16.0/23 | 512 | APNIC |  PK | 18th Aug 2026 |
| 163.52.18.0/24 | 256 | APNIC | PH | 18th Aug 2026 |
| 163.52.19.0/24 | 256 | APNIC | AU | 19th Aug 2026 |
| 163.52.2.0/23 | 512 | APNIC | ID | 14th Aug 2026 |
| 163.52.20.0/23 | 512 | APNIC | AU | 18th Aug 2026 |
| 163.52.22.0/23 | 512 | APNIC | BD | 18th Aug 2026 |
| 163.52.24.0/23 | 512 | APNIC | BD | 18th Aug 2026 |
| 163.52.26.0/23 | 512 | APNIC | PK | 19th Aug 2026 |
| 163.52.28.0/23 | 512 | APNIC | CN | 19th Aug 2026 |
| 163.52.30.0/23 | 512 | APNIC | BD | 19th Aug 2026 |
| 163.52.32.0/23 | 512 | APNIC |  BT | 19th Aug 2026 |
| 163.52.34.0/24 | 256 | APNIC | AU | 20th Aug 2026 |
| 163.52.35.0/24 | 256 | APNIC | ID | 20th Aug 2026 |
| 163.52.36.0/23 | 512 | APNIC | IN | 20th Aug 2026 |
| 163.52.38.0/24 | 256 | APNIC | IN | 21st Aug 2026 |
| 163.52.39.0/24 | 256 | APNIC | PH | 21st Aug 2026 |
| 163.52.4.0/23 | 512 | APNIC |  NP | 14th Aug 2026 |