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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.159.78.0/24 | 256 | ARIN |  US | 29th Apr 1992 |
| 192.159.79.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.80.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.81.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.82.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.84.0/24 | 256 | RIPE NCC |  ES | 29th Apr 1992 |
| 192.159.85.0/24 | 256 | RIPE NCC | ES | 29th Apr 1992 |
| 192.159.86.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.87.0/24 | 256 | ARIN | US | 29th Apr 1992 |
| 192.159.89.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.159.9.0/24 | 256 | ARIN | US | 20th Apr 1992 |
| 192.159.90.0/24 | 256 | RIPE NCC |  BE | 5th May 1992 |
| 192.159.92.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.159.93.0/24 | 256 | ARIN | US | 10th Jul 2015 |
| 192.159.95.0/24 | 256 | RIPE NCC |  DE | 28th Apr 1992 |
| 192.159.96.0/24 | 256 | ARIN | US | 28th Apr 1992 |
| 192.159.97.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.159.98.0/24 | 256 | ARIN | US | 6th May 1992 |
| 192.16.0.0/18 | 16.4k | ARIN | US | 29th Nov 2012 |
| 192.16.123.0/24 | 256 | RIPE NCC |  SE | 22nd Jul 1986 |
| 192.16.128.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.129.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.130.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.138.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.139.0/24 | 256 | RIPE NCC | SE | 23rd Oct 1992 |
| 192.16.141.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.142.0/24 | 256 | RIPE NCC | SE | 22nd Jul 1986 |
| 192.16.147.0/24 | 256 | RIPE NCC | SE | 12th Sept 1996 |
| 192.16.154.0/24 | 256 | RIPE NCC | SE | 26th Oct 1992 |
| 192.16.170.0/24 | 256 | ARIN | US | 17th Jul 1990 |
| 192.16.171.0/24 | 256 | ARIN | US | 26th Aug 1986 |
| 192.16.172.0/24 | 256 | ARIN | US | 22nd Oct 1986 |
| 192.16.179.0/24 | 256 | APNIC |  JP | 4th Nov 1986 |
| 192.16.181.0/24 | 256 | ARIN | US | 7th Nov 1986 |
| 192.16.182.0/24 | 256 | ARIN | US | 7th Nov 1986 |
| 192.16.183.0/24 | 256 | RIPE NCC |  NL | 7th Nov 1986 |
| 192.16.187.0/24 | 256 | RIPE NCC | NL | 7th Nov 1986 |
| 192.16.193.0/24 | 256 | RIPE NCC | NL | 7th Nov 1986 |
| 192.16.198.0/24 | 256 | RIPE NCC | NL | 7th Nov 1986 |
| 192.16.203.0/24 | 256 | ARIN | US | 21st Nov 1986 |
| 192.16.205.0/24 | 256 | ARIN |  CA | 29th Mar 1989 |
| 192.16.206.0/24 | 256 | ARIN | CA | 29th Mar 1989 |
| 192.16.207.0/24 | 256 | ARIN | CA | 19th Jul 1989 |
| 192.16.208.0/24 | 256 | ARIN | CA | 19th Jul 1989 |
| 192.16.209.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.210.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.211.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.212.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.213.0/24 | 256 | ARIN | CA | 21st Nov 1988 |
| 192.16.214.0/24 | 256 | ARIN | CA | 21st Nov 1988 |