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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
27,007 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.195.97.0/24 | 256 | ARIN |  US | 21st Jul 1992 |
| 192.195.99.0/24 | 256 | ARIN | US | 21st Jul 1992 |
| 192.196.216.0/23 | 512 | ARIN | US | 21st Jun 2017 |
| 192.196.219.0/24 | 256 | ARIN | US | 18th May 2023 |
| 192.197.144.0/24 | 256 | ARIN | US | 2nd Nov 2018 |
| 192.197.158.0/24 | 256 | ARIN | US | 14th Jan 1993 |
| 192.197.159.0/24 | 256 | ARIN | US | 14th Jan 1993 |
| 192.197.160.0/24 | 256 | ARIN | US | 14th Jan 1993 |
| 192.197.199.0/24 | 256 | ARIN | US | 30th Mar 1993 |
| 192.197.200.0/24 | 256 | ARIN | US | 30th Mar 1993 |
| 192.197.224.0/24 | 256 | ARIN | US | 26th Feb 1993 |
| 192.198.16.0/21 | 2k | ARIN | US | 7th Apr 1997 |
| 192.198.187.0/24 | 256 | ARIN | US | 7th Mar 2013 |
| 192.198.224.0/20 | 4.1k | ARIN | US | 31st Jul 2013 |
| 192.198.28.0/24 | 256 | ARIN | US | 22nd Dec 2015 |
| 192.198.72.0/22 | 1k | ARIN | US | 11th Aug 1992 |
| 192.198.76.0/23 | 512 | ARIN | US | 11th Aug 1992 |
| 192.198.78.0/24 | 256 | ARIN | US | 11th Aug 1992 |
| 192.199.1.0/24 | 256 | ARIN | US | 6th Aug 1992 |
| 192.199.128.0/19 | 8.2k | ARIN | US | 7th Aug 1992 |
| 192.199.160.0/20 | 4.1k | ARIN | US | 7th Aug 1992 |
| 192.199.176.0/23 | 512 | ARIN | US | 7th Aug 1992 |
| 192.199.2.0/23 | 512 | ARIN | US | 6th Aug 1992 |
| 192.199.4.0/22 | 1k | ARIN | US | 6th Aug 1992 |
| 192.199.8.0/23 | 512 | ARIN | US | 6th Aug 1992 |
| 192.20.192.0/19 | 8.2k | ARIN | US | 27th Nov 1985 |
| 192.20.224.0/24 | 256 | ARIN | US | 27th Nov 1985 |
| 192.20.226.0/23 | 512 | ARIN | US | 27th Nov 1985 |
| 192.20.228.0/22 | 1k | ARIN | US | 27th Nov 1985 |
| 192.20.232.0/22 | 1k | ARIN | US | 27th Nov 1985 |
| 192.20.236.0/23 | 512 | ARIN | US | 27th Nov 1985 |
| 192.20.238.0/24 | 256 | ARIN | US | 27th Nov 1985 |
| 192.20.239.0/24 | 256 | ARIN | US | 27th Nov 1985 |
| 192.200.16.0/20 | 4.1k | ARIN | US | 25th Sept 2012 |
| 192.200.32.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.33.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.34.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.35.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.36.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.37.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.38.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.39.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.40.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.41.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.42.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.43.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.44.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.45.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.46.0/24 | 256 | ARIN | US | 22nd Jul 1992 |
| 192.200.47.0/24 | 256 | ARIN | US | 22nd Jul 1992 |