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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,285 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.168.40.0/24 | 256 | ARIN |  US | 15th Feb 1994 |
| 199.175.1.0/24 | 256 | ARIN |  CA | 16th Feb 1994 |
| 199.175.10.0/23 | 512 | ARIN | CA | 10th Mar 1994 |
| 199.175.100.0/24 | 256 | ARIN | CA | 14th Feb 1994 |
| 199.175.104.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.105.0/24 | 256 | ARIN | CA | 30th Aug 1994 |
| 199.175.108.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.109.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.110.0/23 | 512 | ARIN | US | 16th Feb 1994 |
| 199.175.12.0/22 | 1k | ARIN | CA | 10th Mar 1994 |
| 199.175.120.0/22 | 1k | ARIN | US | 16th Feb 1994 |
| 199.175.136.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.137.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.140.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.141.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.142.0/23 | 512 | ARIN | CA | 16th Feb 1994 |
| 199.175.144.0/21 | 2k | ARIN | CA | 16th Feb 1994 |
| 199.175.152.0/22 | 1k | ARIN | CA | 16th Feb 1994 |
| 199.175.156.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.158.0/23 | 512 | ARIN | CA | 16th Feb 1994 |
| 199.175.170.0/23 | 512 | ARIN | CA | 16th Feb 1994 |
| 199.175.172.0/22 | 1k | ARIN | CA | 16th Feb 1994 |
| 199.175.176.0/22 | 1k | ARIN | CA | 16th Feb 1994 |
| 199.175.189.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.190.0/23 | 512 | ARIN | CA | 16th Feb 1994 |
| 199.175.192.0/21 | 2k | ARIN | CA | 16th Feb 1994 |
| 199.175.2.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.225.0/24 | 256 | ARIN | CA | 20th Feb 1997 |
| 199.175.226.0/23 | 512 | ARIN | CA | 22nd Jun 1994 |
| 199.175.228.0/24 | 256 | ARIN | CA | 22nd Jun 1994 |
| 199.175.229.0/24 | 256 | ARIN | CA | 23rd Jun 1994 |
| 199.175.230.0/24 | 256 | ARIN | CA | 19th Mar 1997 |
| 199.175.233.0/24 | 256 | ARIN | CA | 6th Jun 1994 |
| 199.175.234.0/23 | 512 | ARIN | CA | 1st Jun 1994 |
| 199.175.236.0/23 | 512 | ARIN | CA | 23rd May 1994 |
| 199.175.238.0/24 | 256 | ARIN | CA | 23rd May 1994 |
| 199.175.239.0/24 | 256 | ARIN | CA | 17th May 1994 |
| 199.175.240.0/24 | 256 | ARIN | US | 7th Dec 2021 |
| 199.175.245.0/24 | 256 | ARIN | CA | 15th Mar 1994 |
| 199.175.246.0/23 | 512 | ARIN | CA | 15th Mar 1994 |
| 199.175.248.0/22 | 1k | ARIN | CA | 15th Mar 1994 |
| 199.175.252.0/23 | 512 | ARIN | CA | 15th Mar 1994 |
| 199.175.254.0/24 | 256 | ARIN | CA | 15th Mar 1994 |
| 199.175.3.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.4.0/24 | 256 | ARIN | CA | 16th Feb 1994 |
| 199.175.40.0/24 | 256 | ARIN | CA | 16th May 1994 |
| 199.175.64.0/19 | 8.2k | ARIN | CA | 8th Apr 1994 |
| 199.175.8.0/23 | 512 | ARIN | CA | 25th Mar 1994 |
| 199.180.12.0/23 | 512 | ARIN | US | 18th Feb 1994 |
| 199.180.14.0/24 | 256 | ARIN | US | 18th Feb 1994 |