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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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.
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Countries with unannounced space registered through ARIN, largest first.
Unannounced blocks in United States
26,315 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.233.163.0/24 | 256 | ARIN |  US | 24th Mar 1995 |
| 199.233.164.0/24 | 256 | ARIN | US | 24th Mar 1995 |
| 199.233.165.0/24 | 256 | ARIN | US | 24th Mar 1995 |
| 199.233.166.0/24 | 256 | ARIN | US | 24th Mar 1995 |
| 199.233.167.0/24 | 256 | ARIN | US | 24th Mar 1995 |
| 199.233.168.0/24 | 256 | ARIN | US | 30th Mar 1995 |
| 199.233.169.0/24 | 256 | ARIN | US | 10th Apr 1995 |
| 199.233.170.0/24 | 256 | ARIN | US | 24th Apr 1995 |
| 199.233.172.0/24 | 256 | ARIN | US | 24th Apr 1995 |
| 199.233.173.0/24 | 256 | ARIN | US | 24th Apr 1995 |
| 199.233.174.0/24 | 256 | ARIN | US | 25th Apr 1995 |
| 199.233.175.0/24 | 256 | ARIN | US | 4th May 1995 |
| 199.233.176.0/24 | 256 | ARIN | US | 5th May 1995 |
| 199.233.177.0/24 | 256 | ARIN | US | 5th May 1995 |
| 199.233.180.0/24 | 256 | ARIN | US | 5th May 1995 |
| 199.233.185.0/24 | 256 | ARIN | US | 5th May 1995 |
| 199.233.186.0/24 | 256 | ARIN | US | 5th May 1995 |
| 199.233.187.0/24 | 256 | ARIN | US | 15th May 1995 |
| 199.233.188.0/24 | 256 | ARIN | US | 15th May 1995 |
| 199.233.189.0/24 | 256 | ARIN | US | 24th May 1995 |
| 199.233.192.0/24 | 256 | ARIN | US | 11th Apr 2012 |
| 199.233.193.0/24 | 256 | ARIN | US | 2nd Jun 1995 |
| 199.233.194.0/24 | 256 | ARIN | US | 7th Jun 1995 |
| 199.233.195.0/24 | 256 | ARIN | US | 8th Jun 1995 |
| 199.233.196.0/23 | 512 | ARIN | US | 9th Jun 1995 |
| 199.233.198.0/23 | 512 | ARIN | US | 15th Jun 1995 |
| 199.233.200.0/24 | 256 | ARIN | US | 30th Jun 1995 |
| 199.233.201.0/24 | 256 | ARIN | US | 3rd Jul 1995 |
| 199.233.204.0/24 | 256 | ARIN | US | 11th Apr 2012 |
| 199.233.211.0/24 | 256 | ARIN | US | 14th Jul 1995 |
| 199.233.212.0/24 | 256 | ARIN | US | 20th Jul 1995 |
| 199.233.213.0/24 | 256 | ARIN | US | 27th Jul 1995 |
| 199.233.214.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 199.233.215.0/24 | 256 | ARIN | US | 31st Oct 1995 |
| 199.233.216.0/24 | 256 | ARIN | US | 21st Nov 1995 |
| 199.233.24.0/23 | 512 | ARIN | US | 13th Apr 1994 |
| 199.233.48.0/21 | 2k | ARIN | US | 11th Aug 2011 |
| 199.233.56.0/24 | 256 | ARIN | US | 11th Aug 2011 |
| 199.233.57.0/24 | 256 | ARIN | US | 13th Jul 2012 |
| 199.233.64.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.65.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.66.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.67.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.69.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.70.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.71.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.72.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.73.0/24 | 256 | ARIN | US | 31st Jan 1995 |
| 199.233.75.0/24 | 256 | ARIN | US | 9th Feb 1995 |
| 199.233.76.0/24 | 256 | ARIN | US | 9th Feb 1995 |