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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,310 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 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 |
| 199.74.136.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.137.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.138.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.139.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.14.0/24 | 256 | ARIN | US | 6th Dec 1993 |
| 199.74.140.0/24 | 256 | ARIN | US | 22nd Jan 1994 |
| 199.74.142.0/24 | 256 | ARIN | US | 22nd Jan 1994 |