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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,201 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.48.108.0/24 | 256 | ARIN |  US | 7th Feb 1989 |
| 192.48.114.0/24 | 256 | ARIN | US | 10th Feb 1989 |
| 192.48.115.0/24 | 256 | ARIN | US | 10th Feb 1989 |
| 192.48.116.0/24 | 256 | ARIN | US | 10th Feb 1989 |
| 192.48.123.0/24 | 256 | ARIN | US | 13th Feb 1989 |
| 192.48.124.0/24 | 256 | ARIN | US | 14th Feb 1989 |
| 192.48.126.0/24 | 256 | ARIN | US | 15th Feb 1989 |
| 192.48.127.0/24 | 256 | ARIN | US | 15th Feb 1989 |
| 192.48.128.0/23 | 512 | ARIN | US | 15th Feb 1989 |
| 192.48.130.0/23 | 512 | ARIN | US | 16th Feb 1989 |
| 192.48.132.0/24 | 256 | ARIN | US | 16th Feb 1989 |
| 192.48.133.0/24 | 256 | ARIN | US | 21st Feb 1989 |
| 192.48.134.0/24 | 256 | ARIN | US | 21st Feb 1989 |
| 192.48.135.0/24 | 256 | ARIN | US | 21st Feb 1989 |
| 192.48.136.0/24 | 256 | ARIN | US | 22nd Aug 2014 |
| 192.48.137.0/24 | 256 | ARIN | US | 21st Feb 1989 |
| 192.48.139.0/24 | 256 | ARIN | US | 21st Feb 1989 |
| 192.48.140.0/24 | 256 | ARIN | US | 20th Aug 2014 |
| 192.48.141.0/24 | 256 | ARIN |  CA | 22nd Feb 1989 |
| 192.48.143.0/24 | 256 | ARIN | US | 23rd Feb 1989 |
| 192.48.144.0/24 | 256 | ARIN | US | 24th Feb 1989 |
| 192.48.145.0/24 | 256 | RIPE NCC |  DE | 27th Feb 1989 |
| 192.48.156.0/22 | 1k | ARIN | US | 27th Feb 1989 |
| 192.48.192.0/20 | 4.1k | ARIN | US | 27th Feb 1989 |
| 192.48.217.0/24 | 256 | ARIN | US | 1st Mar 1989 |
| 192.48.221.0/24 | 256 | ARIN | US | 6th Mar 1989 |
| 192.48.222.0/24 | 256 | ARIN | US | 6th Mar 1989 |
| 192.48.224.0/24 | 256 | RIPE NCC | DE | 6th Mar 1989 |
| 192.48.226.0/24 | 256 | ARIN | US | 10th Mar 1989 |
| 192.48.231.0/24 | 256 | RIPE NCC | DE | 12th Mar 1989 |
| 192.48.232.0/24 | 256 | ARIN | US | 12th Mar 1989 |
| 192.48.234.0/24 | 256 | ARIN | CA | 8th Dec 1997 |
| 192.48.235.0/24 | 256 | ARIN | US | 14th Mar 1989 |
| 192.48.244.0/24 | 256 | ARIN | US | 23rd Mar 1989 |
| 192.48.245.0/24 | 256 | ARIN | US | 23rd Mar 1989 |
| 192.48.246.0/24 | 256 | ARIN | US | 23rd Mar 1989 |
| 192.48.247.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.48.248.0/24 | 256 | APNIC |  AU | 11th Feb 2011 |
| 192.48.249.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.48.250.0/24 | 256 | ARIN | US | 27th Mar 1989 |
| 192.48.251.0/24 | 256 | ARIN | US | 28th Mar 1989 |
| 192.48.252.0/24 | 256 | ARIN | US | 28th Mar 1989 |
| 192.48.253.0/24 | 256 | AFRINIC |  ZA | 28th Mar 1989 |
| 192.48.254.0/24 | 256 | ARIN | US | 30th Mar 1989 |
| 192.48.30.0/24 | 256 | ARIN | US | 16th Jan 1989 |
| 192.48.33.0/24 | 256 | ARIN | US | 1st Jul 2026 |
| 192.48.34.0/24 | 256 | ARIN | US | 18th Jan 1989 |
| 192.48.36.0/24 | 256 | ARIN | US | 29th Aug 2025 |
| 192.48.38.0/23 | 512 | ARIN | US | 29th Aug 2025 |
| 192.48.40.0/21 | 2k | ARIN | US | 25th Jan 1989 |