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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 unannounced space registered through ARIN, largest first.
Unannounced blocks registered through ARIN
30,476 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.71.153.0/24 | 256 | ARIN |  CA | 1st Dec 1993 |
| 199.71.155.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.156.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.157.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.158.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.159.0/24 | 256 | ARIN |  US | 31st Aug 2015 |
| 199.71.16.0/20 | 4.1k | ARIN | CA | 14th Dec 1993 |
| 199.71.161.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.162.0/23 | 512 | ARIN | CA | 11th Mar 1994 |
| 199.71.164.0/22 | 1k | ARIN | CA | 11th Mar 1994 |
| 199.71.187.0/24 | 256 | ARIN | US | 3rd Mar 1994 |
| 199.71.189.0/24 | 256 | ARIN | CA | 25th Feb 1994 |
| 199.71.190.0/24 | 256 | ARIN | CA | 13th May 1994 |
| 199.71.191.0/24 | 256 | ARIN | CA | 10th Feb 1994 |
| 199.71.192.0/20 | 4.1k | ARIN | CA | 1st Feb 1994 |
| 199.71.208.0/24 | 256 | ARIN | CA | 8th Feb 1994 |
| 199.71.232.0/22 | 1k | ARIN | US | 6th Jan 2012 |
| 199.71.248.0/22 | 1k | ARIN | CA | 22nd Mar 1994 |
| 199.71.253.0/24 | 256 | ARIN | CA | 12th May 1994 |
| 199.71.254.0/24 | 256 | ARIN | CA | 12th May 1994 |
| 199.71.3.0/24 | 256 | ARIN | CA | 18th Jan 1994 |
| 199.71.32.0/20 | 4.1k | ARIN | CA | 3rd Jan 1994 |
| 199.71.48.0/22 | 1k | ARIN | CA | 3rd Jan 1994 |
| 199.71.68.0/24 | 256 | ARIN | US | 13th Dec 2021 |
| 199.71.69.0/24 | 256 | ARIN | CA | 1st Apr 1994 |
| 199.71.71.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.71.72.0/21 | 2k | ARIN | CA | 1st Dec 1993 |
| 199.71.8.0/24 | 256 | ARIN | CA | 6th Apr 1994 |
| 199.71.84.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.71.85.0/24 | 256 | ARIN | CA | 31st Mar 1994 |
| 199.71.86.0/24 | 256 | ARIN | CA | 23rd Mar 1994 |
| 199.71.87.0/24 | 256 | ARIN | CA | 24th Mar 1994 |
| 199.71.88.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.71.89.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.71.9.0/24 | 256 | ARIN | CA | 14th Apr 1994 |
| 199.71.90.0/24 | 256 | ARIN | CA | 25th Mar 1994 |
| 199.71.91.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.92.0/24 | 256 | ARIN | CA | 1st Dec 1993 |
| 199.71.94.0/23 | 512 | ARIN | CA | 1st Dec 1993 |
| 199.71.96.0/21 | 2k | ARIN | CA | 15th Mar 1994 |
| 199.73.116.0/22 | 1k | ARIN | US | 10th Jan 2012 |
| 199.73.12.0/22 | 1k | ARIN | US | 11th Aug 2023 |
| 199.73.24.0/24 | 256 | ARIN | US | 2nd Dec 1993 |
| 199.73.40.0/23 | 512 | ARIN | US | 6th Dec 1993 |
| 199.73.64.0/20 | 4.1k | ARIN | US | 20th Dec 1993 |
| 199.73.8.0/23 | 512 | ARIN | US | 2nd Dec 1993 |
| 199.73.80.0/24 | 256 | ARIN | US | 20th Dec 1993 |
| 199.73.88.0/22 | 1k | ARIN | US | 5th Oct 2022 |
| 199.74.12.0/23 | 512 | ARIN | US | 6th Dec 1993 |
| 199.74.133.0/24 | 256 | ARIN | US | 22nd Jan 1994 |