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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.135.97.0/24 | 256 | APNIC |  ID | 29th Jul 2025 |
| 192.135.99.0/24 | 256 | APNIC |  HK | 4th Mar 2019 |
| 192.136.1.0/24 | 256 | ARIN |  US | 19th Dec 1991 |
| 192.136.10.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.100.0/23 | 512 | RIPE NCC |  FI | 16th Sept 2004 |
| 192.136.102.0/24 | 256 | RIPE NCC | FI | 16th Sept 2004 |
| 192.136.106.0/24 | 256 | ARIN | US | 8th Jan 1992 |
| 192.136.107.0/24 | 256 | ARIN | US | 8th Jan 1992 |
| 192.136.11.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.112.0/24 | 256 | ARIN | US | 14th Feb 1992 |
| 192.136.114.0/23 | 512 | ARIN |  CA | 13th Jan 1992 |
| 192.136.12.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.135.0/24 | 256 | ARIN | US | 28th Apr 2015 |
| 192.136.14.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.150.0/24 | 256 | ARIN | US | 7th Feb 1992 |
| 192.136.151.0/24 | 256 | ARIN | US | 7th Feb 1992 |
| 192.136.152.0/24 | 256 | ARIN | US | 7th Feb 1992 |
| 192.136.154.0/24 | 256 | RIPE NCC |  GB | 8th Feb 1992 |
| 192.136.155.0/24 | 256 | RIPE NCC | GB | 8th Feb 1992 |
| 192.136.156.0/24 | 256 | RIPE NCC |  CH | 22nd Oct 1992 |
| 192.136.17.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.18.0/24 | 256 | RIPE NCC | GB | 19th Dec 1991 |
| 192.136.19.0/24 | 256 | RIPE NCC |  BE | 19th Dec 1991 |
| 192.136.2.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.20.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.21.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.23.0/24 | 256 | RIPE NCC |  NL | 19th Dec 1991 |
| 192.136.25.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.26.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.28.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.29.0/24 | 256 | RIPE NCC | GB | 23rd Dec 1991 |
| 192.136.3.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.31.0/24 | 256 | RIPE NCC |  PT | 23rd Dec 1991 |
| 192.136.32.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.33.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.34.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.35.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.37.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.38.0/24 | 256 | ARIN | US | 23rd Dec 1991 |
| 192.136.4.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.40.0/24 | 256 | RIPE NCC | GB | 24th Dec 1991 |
| 192.136.41.0/24 | 256 | RIPE NCC | CH | 26th Dec 1991 |
| 192.136.44.0/22 | 1k | LACNIC |  NI | 1st Jan 1987 |
| 192.136.5.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.50.0/24 | 256 | ARIN | US | 30th Dec 1991 |
| 192.136.51.0/24 | 256 | RIPE NCC | NL | 30th Dec 1991 |
| 192.136.56.0/24 | 256 | AFRINIC |  BF | 3rd Jan 1992 |
| 192.136.57.0/24 | 256 | AFRINIC | BF | 3rd Jan 1992 |
| 192.136.6.0/24 | 256 | ARIN | US | 19th Dec 1991 |
| 192.136.61.0/24 | 256 | RIPE NCC |  RU | 6th Jan 1992 |