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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.229.192.0/20 | 4.1k | ARIN |  US | 6th Apr 1994 |
| 199.230.0.0/21 | 2k | ARIN | US | 11th Apr 1994 |
| 199.230.30.0/23 | 512 | ARIN | US | 15th Jul 2015 |
| 199.230.32.0/20 | 4.1k | ARIN | US | 15th Feb 1994 |
| 199.230.48.0/22 | 1k | ARIN | US | 15th Feb 1994 |
| 199.230.64.0/19 | 8.2k | ARIN | US | 19th May 1994 |
| 199.230.8.0/23 | 512 | ARIN | US | 11th Apr 1994 |
| 199.231.100.0/22 | 1k | ARIN | US | 5th Jul 2012 |
| 199.231.148.0/23 | 512 | ARIN | US | 12th Mar 1996 |
| 199.231.150.0/24 | 256 | ARIN | US | 12th Mar 1996 |
| 199.231.151.0/24 | 256 | ARIN | US | 1st May 2012 |
| 199.231.234.0/24 | 256 | ARIN | US | 15th Oct 2025 |
| 199.231.6.0/23 | 512 | ARIN | US | 30th Apr 2012 |
| 199.231.8.0/21 | 2k | ARIN | US | 13th Apr 1994 |
| 199.233.0.0/21 | 2k | ARIN | US | 20th Apr 1994 |
| 199.233.100.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.103.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.106.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.107.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.109.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.115.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.117.0/24 | 256 | ARIN | US | 28th Feb 1995 |
| 199.233.12.0/23 | 512 | ARIN | US | 18th Apr 1994 |
| 199.233.120.0/24 | 256 | ARIN | US | 1st Mar 1995 |
| 199.233.121.0/24 | 256 | ARIN | US | 1st Mar 1995 |
| 199.233.122.0/24 | 256 | ARIN | US | 1st Mar 1995 |
| 199.233.123.0/24 | 256 | ARIN | US | 1st Mar 1995 |
| 199.233.124.0/24 | 256 | ARIN | US | 1st Mar 1995 |
| 199.233.126.0/24 | 256 | ARIN | US | 2nd Mar 1995 |
| 199.233.127.0/24 | 256 | ARIN | US | 2nd Mar 1995 |
| 199.233.128.0/24 | 256 | ARIN | US | 2nd Mar 1995 |
| 199.233.130.0/24 | 256 | ARIN | US | 3rd Mar 1995 |
| 199.233.131.0/24 | 256 | ARIN | US | 3rd Mar 1995 |
| 199.233.133.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.134.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.135.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.136.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.137.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.138.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.139.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.140.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.141.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.143.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.145.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.146.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.147.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.148.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.149.0/24 | 256 | ARIN | US | 8th Mar 1995 |
| 199.233.15.0/24 | 256 | ARIN |  CA | 1st Aug 2017 |
| 199.233.150.0/24 | 256 | ARIN | US | 8th Mar 1995 |