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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 192.153.43.0/24 | 256 | ARIN |  US | 10th Aug 1992 |
| 192.153.44.0/24 | 256 | ARIN | US | 12th Apr 1993 |
| 192.153.45.0/24 | 256 | ARIN | US | 10th Aug 1992 |
| 192.153.47.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.153.48.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.49.0/24 | 256 | ARIN | US | 10th Aug 1992 |
| 192.153.50.0/24 | 256 | ARIN | US | 10th Aug 1992 |
| 192.153.54.0/24 | 256 | ARIN | US | 24th Jul 1992 |
| 192.153.55.0/24 | 256 | ARIN | US | 24th Jul 1992 |
| 192.153.56.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.7.0/24 | 256 | ARIN | US | 30th Mar 1992 |
| 192.153.77.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.78.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.79.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.8.0/24 | 256 | ARIN | US | 30th Mar 1992 |
| 192.153.80.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.81.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.82.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.83.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.84.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.85.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.86.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.87.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.89.0/24 | 256 | RIPE NCC |  CH | 31st Mar 1992 |
| 192.153.90.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.91.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.153.94.0/24 | 256 | ARIN | US | 31st Mar 1992 |
| 192.154.10.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.154.11.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.154.12.0/24 | 256 | ARIN | US | 9th Apr 1992 |
| 192.154.127.0/24 | 256 | ARIN | US | 26th May 1992 |
| 192.154.215.0/24 | 256 | ARIN | US | 11th Jan 2013 |
| 192.154.216.0/21 | 2k | ARIN | US | 11th Jan 2013 |
| 192.154.240.0/24 | 256 | ARIN | US | 11th Jan 2013 |
| 192.154.242.0/23 | 512 | ARIN | US | 11th Jan 2013 |
| 192.154.26.0/23 | 512 | ARIN | US | 20th Feb 2015 |
| 192.154.32.0/24 | 256 | ARIN | US | 15th May 1992 |
| 192.154.34.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.154.36.0/24 | 256 | ARIN | US | 30th Jul 1992 |
| 192.154.37.0/24 | 256 | ARIN | US | 13th Apr 1992 |
| 192.154.38.0/24 | 256 | ARIN | US | 28th Sept 1992 |
| 192.154.39.0/24 | 256 | ARIN | US | 28th Sept 1992 |
| 192.154.40.0/24 | 256 | ARIN | US | 28th Sept 1992 |
| 192.154.42.0/24 | 256 | ARIN | US | 23rd Dec 1992 |
| 192.154.44.0/24 | 256 | ARIN | US | 8th Apr 2019 |
| 192.154.45.0/24 | 256 | ARIN | US | 13th Apr 1992 |
| 192.154.49.0/24 | 256 | ARIN | US | 23rd Dec 1992 |
| 192.154.50.0/24 | 256 | ARIN | US | 13th Apr 1992 |
| 192.154.51.0/24 | 256 | ARIN | US | 23rd Dec 1992 |
| 192.154.52.0/24 | 256 | ARIN | US | 23rd Dec 1992 |