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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.133.89.0/24 | 256 | ARIN |  US | 25th Nov 1991 |
| 192.133.9.0/24 | 256 | ARIN | US | 30th Oct 1991 |
| 192.133.91.0/24 | 256 | ARIN | US | 25th Nov 1991 |
| 192.133.93.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.133.94.0/24 | 256 | ARIN | US | 25th Nov 1991 |
| 192.133.96.0/24 | 256 | ARIN | US | 25th Nov 1991 |
| 192.134.143.0/24 | 256 | RIPE NCC |  FR | 21st Apr 1993 |
| 192.135.101.0/24 | 256 | APNIC |  JP | 7th May 1993 |
| 192.135.102.0/24 | 256 | APNIC |  IN | 29th Jul 2025 |
| 192.135.103.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.104.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.105.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.106.0/23 | 512 | APNIC | JP | 5th May 1992 |
| 192.135.108.0/24 | 256 | APNIC | JP | 5th May 1992 |
| 192.135.124.0/22 | 1k | ARIN | US | 5th May 1992 |
| 192.135.128.0/24 | 256 | ARIN | US | 3rd Mar 1992 |
| 192.135.130.0/24 | 256 | ARIN | US | 11th Dec 1991 |
| 192.135.132.0/24 | 256 | ARIN | US | 11th Dec 1991 |
| 192.135.133.0/24 | 256 | RIPE NCC |  AT | 11th Dec 1991 |
| 192.135.134.0/24 | 256 | ARIN | US | 11th Dec 1991 |
| 192.135.135.0/24 | 256 | ARIN | US | 11th Dec 1991 |
| 192.135.138.0/24 | 256 | ARIN | US | 11th Dec 1991 |
| 192.135.139.0/24 | 256 | ARIN | US | 12th Dec 1991 |
| 192.135.140.0/24 | 256 | ARIN | US | 12th Dec 1991 |
| 192.135.143.0/24 | 256 | RIPE NCC |  NO | 12th Dec 1991 |
| 192.135.144.0/24 | 256 | ARIN | US | 13th May 2025 |
| 192.135.145.0/24 | 256 | RIPE NCC |  CH | 1st Sept 1993 |
| 192.135.146.0/23 | 512 | RIPE NCC | CH | 1st Sept 1993 |
| 192.135.160.0/22 | 1k | RIPE NCC | CH | 1st Sept 1993 |
| 192.135.164.0/24 | 256 | RIPE NCC | CH | 1st Sept 1993 |
| 192.135.169.0/24 | 256 | ARIN | US | 13th Dec 1991 |
| 192.135.170.0/24 | 256 | ARIN | US | 13th Dec 1991 |
| 192.135.171.0/24 | 256 | ARIN | US | 13th Dec 1991 |
| 192.135.172.0/24 | 256 | ARIN | US | 13th Dec 1991 |
| 192.135.173.0/24 | 256 | ARIN | US | 13th Dec 1991 |
| 192.135.175.0/24 | 256 | RIPE NCC | FR | 16th Dec 1991 |
| 192.135.182.0/24 | 256 | ARIN | US | 17th Dec 1991 |
| 192.135.184.0/24 | 256 | ARIN | US | 20th Mar 1996 |
| 192.135.190.0/24 | 256 | ARIN | US | 17th Dec 1991 |
| 192.135.193.0/24 | 256 | ARIN | US | 17th Dec 1991 |
| 192.135.197.0/24 | 256 | ARIN | US | 18th Dec 1991 |
| 192.135.2.0/24 | 256 | ARIN | US | 20th Nov 1991 |
| 192.135.205.0/24 | 256 | ARIN | US | 18th Dec 1991 |
| 192.135.214.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.135.215.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.135.220.0/24 | 256 | ARIN | US | 30th Dec 1991 |
| 192.135.221.0/24 | 256 | ARIN | US | 30th Dec 1991 |
| 192.135.225.0/24 | 256 | RIPE NCC |  IE | 30th Dec 1991 |
| 192.135.228.0/24 | 256 | ARIN | US | 30th Dec 1991 |
| 192.135.234.0/24 | 256 | RIPE NCC |  GB | 30th Dec 1991 |