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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 the most unannounced blocks, largest first.
Unannounced blocks in United States
26,963 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 169.141.0.0/16 | 65.5k | ARIN |  US | 8th Nov 1994 |
| 169.148.184.0/22 | 1k | ARIN | US | 11th Jan 2019 |
| 169.150.112.0/20 | 4.1k | ARIN | US | 28th Dec 2021 |
| 169.155.0.0/19 | 8.2k | ARIN | US | 3rd Jan 1995 |
| 169.155.172.0/23 | 512 | ARIN | US | 2nd Oct 2026 |
| 169.155.174.0/24 | 256 | ARIN | US | 18th Sept 2026 |
| 169.155.175.0/24 | 256 | ARIN | US | 28th Aug 2026 |
| 169.155.176.0/20 | 4.1k | ARIN | US | 3rd Jan 1995 |
| 169.155.32.0/21 | 2k | ARIN | US | 3rd Jan 1995 |
| 169.155.43.0/24 | 256 | ARIN | US | 22nd Sept 2026 |
| 169.155.64.0/20 | 4.1k | ARIN | US | 3rd Jan 1995 |
| 169.155.80.0/21 | 2k | ARIN | US | 3rd Jan 1995 |
| 169.155.96.0/20 | 4.1k | ARIN | US | 3rd Jan 1995 |
| 169.16.0.0/12 | 1M | ARIN | US | 25th Aug 1993 |
| 169.176.0.0/13 | 524k | ARIN | US | 23rd Feb 1995 |
| 169.184.0.0/16 | 65.5k | ARIN | US | 23rd Feb 1995 |
| 169.185.0.0/16 | 65.5k | ARIN | US | 23rd Feb 1995 |
| 169.186.0.0/15 | 131k | ARIN | US | 23rd Feb 1995 |
| 169.188.0.0/14 | 262k | ARIN | US | 23rd Feb 1995 |
| 169.192.0.0/14 | 262k | ARIN | US | 23rd Feb 1995 |
| 169.197.135.0/24 | 256 | ARIN | US | 3rd Apr 2023 |
| 169.197.150.0/24 | 256 | ARIN | US | 13th Jan 2021 |
| 169.197.151.0/24 | 256 | ARIN | US | 15th Jan 2021 |
| 169.197.160.0/22 | 1k | ARIN | US | 4th Jan 2021 |
| 169.197.168.0/22 | 1k | ARIN | US | 1st Apr 2024 |
| 169.197.181.0/24 | 256 | ARIN | US | 1st Mar 2021 |
| 169.206.0.0/16 | 65.5k | ARIN | US | 30th Apr 1995 |
| 169.225.0.0/16 | 65.5k | ARIN | US | 14th Jun 1995 |
| 169.242.0.0/16 | 65.5k | ARIN | US | 5th Oct 1995 |
| 169.243.0.0/16 | 65.5k | ARIN | US | 5th Oct 1995 |
| 169.245.0.0/16 | 65.5k | ARIN | US | 9th Jul 1996 |
| 169.246.0.0/15 | 131k | ARIN | US | 9th Jul 1996 |
| 169.248.0.0/14 | 262k | ARIN | US | 9th Jul 1996 |
| 169.64.0.0/10 | 4.2M | ARIN | US | 25th Aug 1993 |
| 170.0.4.0/22 | 1k | ARIN | US | 11th Jan 2022 |
| 170.1.0.0/16 | 65.5k | ARIN | US | 30th Nov 1993 |
| 170.10.76.0/22 | 1k | ARIN | US | 27th Jan 2022 |
| 170.10.80.0/22 | 1k | ARIN | US | 27th Jan 2022 |
| 170.100.0.0/17 | 32.8k | ARIN | US | 21st Dec 2022 |
| 170.100.132.0/22 | 1k | ARIN | US | 24th Mar 1994 |
| 170.100.136.0/21 | 2k | ARIN | US | 24th Mar 1994 |
| 170.100.144.0/23 | 512 | ARIN | US | 24th Mar 1994 |
| 170.100.146.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 170.100.147.0/24 | 256 | RIPE NCC | US | 24th Mar 1994 |
| 170.100.205.0/24 | 256 | ARIN | US | 24th Mar 1994 |
| 170.100.216.0/21 | 2k | ARIN | US | 24th Mar 1994 |
| 170.102.0.0/18 | 16.4k | ARIN | US | 29th Mar 1994 |
| 170.102.64.0/19 | 8.2k | ARIN | US | 29th Mar 1994 |
| 170.102.96.0/20 | 4.1k | ARIN | US | 29th Mar 1994 |
| 170.107.0.0/16 | 65.5k | ARIN | US | 7th Apr 1994 |