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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
26,955 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.48.40.0/21 | 2k | ARIN | 25th Jan 1989 | |
| 192.48.48.0/20 | 4.1k | ARIN | 25th Jan 1989 | |
| 192.48.64.0/21 | 2k | ARIN | 25th Jan 1989 | |
| 192.48.72.0/22 | 1k | ARIN | 25th Jan 1989 | |
| 192.48.76.0/24 | 256 | ARIN | 25th Jan 1989 | |
| 192.48.77.0/24 | 256 | ARIN | 6th Feb 2026 | |
| 192.48.81.0/24 | 256 | ARIN | 26th Jan 1989 | |
| 192.48.84.0/22 | 1k | ARIN | 30th Nov 2012 | |
| 192.48.88.0/22 | 1k | ARIN | 3rd Dec 2012 | |
| 192.48.93.0/24 | 256 | ARIN | 30th Jan 1989 | |
| 192.48.94.0/24 | 256 | ARIN | 31st Jan 1989 | |
| 192.48.99.0/24 | 256 | ARIN | 2nd Feb 1989 | |
| 192.5.10.0/24 | 256 | ARIN | 19th Jan 1983 | |
| 192.5.100.0/24 | 256 | ARIN | 1st Nov 1985 | |
| 192.5.103.0/24 | 256 | ARIN | 1st Nov 1989 | |
| 192.5.105.0/24 | 256 | ARIN | 10th Aug 1984 | |
| 192.5.107.0/24 | 256 | ARIN | 8th Oct 1984 | |
| 192.5.108.0/24 | 256 | ARIN | 8th Oct 1984 | |
| 192.5.111.0/24 | 256 | ARIN | 7th Jul 1988 | |
| 192.5.112.0/24 | 256 | ARIN | 7th Jul 1988 | |
| 192.5.13.0/24 | 256 | ARIN | 4th Apr 1983 | |
| 192.5.133.0/24 | 256 | ARIN | 11th Nov 1985 | |
| 192.5.135.0/24 | 256 | ARIN | 23rd Dec 1985 | |
| 192.5.147.0/24 | 256 | ARIN | 2nd Jun 1997 | |
| 192.5.149.0/24 | 256 | ARIN | 27th Mar 1986 | |
| 192.5.150.0/24 | 256 | ARIN | 28th Mar 1986 | |
| 192.5.151.0/24 | 256 | ARIN | 18th Feb 2014 | |
| 192.5.152.0/23 | 512 | ARIN | 6th Mar 1991 | |
| 192.5.156.0/24 | 256 | ARIN | 6th Mar 1991 | |
| 192.5.164.0/24 | 256 | ARIN | 10th Apr 1986 | |
| 192.5.165.0/24 | 256 | ARIN | 17th Apr 1986 | |
| 192.5.167.0/24 | 256 | ARIN | 21st Apr 1986 | |
| 192.5.168.0/24 | 256 | ARIN | 21st Apr 1986 | |
| 192.5.169.0/24 | 256 | ARIN | 21st Apr 1986 | |
| 192.5.20.0/24 | 256 | ARIN | 6th Jul 1983 | |
| 192.5.202.0/24 | 256 | ARIN | 24th Apr 1986 | |
| 192.5.214.0/24 | 256 | ARIN | 9th Jun 1986 | |
| 192.5.217.0/24 | 256 | ARIN | 2nd May 1990 | |
| 192.5.220.0/24 | 256 | ARIN | 30th Jun 1986 | |
| 192.5.223.0/24 | 256 | ARIN | 30th Jun 1986 | |
| 192.5.224.0/24 | 256 | ARIN | 8th Jul 1986 | |
| 192.5.225.0/24 | 256 | ARIN | 9th Jul 1986 | |
| 192.5.226.0/23 | 512 | ARIN | 9th Jul 1986 | |
| 192.5.228.0/22 | 1k | ARIN | 9th Jul 1986 | |
| 192.5.232.0/22 | 1k | ARIN | 9th Jul 1986 | |
| 192.5.236.0/24 | 256 | ARIN | 9th Jul 1986 | |
| 192.5.237.0/24 | 256 | ARIN | 11th Aug 1988 | |
| 192.5.238.0/24 | 256 | ARIN | 31st Mar 1989 | |
| 192.5.244.0/22 | 1k | ARIN | 29th Jul 1986 | |
| 192.5.26.0/24 | 256 | ARIN | 19th Apr 1990 |