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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,248 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.148.241.0/24 | 256 | ARIN |  US | 5th Aug 1993 |
| 198.148.242.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.243.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.244.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.245.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.246.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.247.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.248.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.249.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.250.0/24 | 256 | ARIN | US | 5th Aug 1993 |
| 198.148.251.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.148.252.0/23 | 512 | ARIN | US | 25th Jun 1993 |
| 198.148.254.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.148.255.0/24 | 256 | ARIN | US | 4th Nov 2013 |
| 198.148.26.0/23 | 512 | ARIN | US | 9th May 2013 |
| 198.148.32.0/19 | 8.2k | ARIN | US | 29th Apr 1993 |
| 198.148.4.0/23 | 512 | ARIN | US | 27th Apr 1993 |
| 198.148.8.0/22 | 1k | ARIN | US | 27th Apr 1993 |
| 198.149.0.0/16 | 65.5k | ARIN | US | 28th Apr 1993 |
| 198.15.18.0/24 | 256 | APNIC |  PH | 29th Jan 2026 |
| 198.15.19.0/24 | 256 | APNIC |  ID | 29th Jan 2026 |
| 198.15.20.0/24 | 256 | APNIC |  IN | 29th Jan 2026 |
| 198.15.26.0/24 | 256 | APNIC |  MY | 3rd Feb 2026 |
| 198.15.29.0/24 | 256 | APNIC | IN | 5th Feb 2026 |
| 198.15.31.0/24 | 256 | APNIC |  HK | 10th Feb 2026 |
| 198.15.8.0/21 | 2k | ARIN | US | 1st Dec 1992 |
| 198.151.0.0/21 | 2k | ARIN | US | 3rd May 1993 |
| 198.151.129.0/24 | 256 | ARIN | US | 17th Jun 1993 |
| 198.151.131.0/24 | 256 | ARIN | US | 17th Jun 1993 |
| 198.151.132.0/24 | 256 | LACNIC |  MX | 17th Jun 1993 |
| 198.151.133.0/24 | 256 | ARIN | US | 17th Jun 1993 |
| 198.151.134.0/24 | 256 | ARIN | US | 17th Jun 1993 |
| 198.151.135.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.136.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.139.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.140.0/23 | 512 | ARIN | US | 18th Jun 1993 |
| 198.151.142.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.144.0/24 | 256 | ARIN | US | 6th Nov 2013 |
| 198.151.145.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.146.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.147.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.148.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.149.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.150.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.151.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.151.152.0/22 | 1k | ARIN | US | 21st Jun 1993 |
| 198.151.156.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.151.158.0/24 | 256 | ARIN | US | 6th Nov 2013 |
| 198.151.159.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.151.16.0/20 | 4.1k | ARIN | US | 10th May 1993 |