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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 150.159.0.0/16 | 65.5k | ARIN |  US | 20th May 1991 |
| 150.16.0.0/15 | 131k | APNIC |  JP | 31st Mar 1997 |
| 150.166.0.0/16 | 65.5k | ARIN | US | 20th May 1991 |
| 150.170.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 150.172.0.0/16 | 65.5k | ARIN | US | 22nd May 1991 |
| 150.190.0.0/16 | 65.5k | ARIN | US | 30th May 1991 |
| 150.195.240.0/20 | 4.1k | ARIN | US | 25th Jan 2021 |
| 150.2.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.20.0.0/16 | 65.5k | APNIC | JP | 4th Mar 1993 |
| 150.205.0.0/16 | 65.5k | RIPE NCC |  CH | 7th Jun 1991 |
| 150.21.0.0/16 | 65.5k | APNIC | JP | 11th Jul 1994 |
| 150.213.0.0/16 | 65.5k | RIPE NCC | CH | 11th Jun 1991 |
| 150.215.0.0/16 | 65.5k | ARIN | US | 11th Jun 1991 |
| 150.22.128.0/17 | 32.8k | APNIC | JP | 3rd Nov 1992 |
| 150.22.16.0/20 | 4.1k | APNIC | JP | 3rd Nov 1992 |
| 150.22.32.0/19 | 8.2k | APNIC | JP | 3rd Nov 1992 |
| 150.22.4.0/22 | 1k | APNIC | JP | 3rd Nov 1992 |
| 150.22.64.0/20 | 4.1k | APNIC | JP | 3rd Nov 1992 |
| 150.22.8.0/21 | 2k | APNIC | JP | 3rd Nov 1992 |
| 150.22.80.0/22 | 1k | APNIC | JP | 3rd Nov 1992 |
| 150.22.84.0/22 | 1k | APNIC | JP | 3rd Nov 1992 |
| 150.22.88.0/21 | 2k | APNIC | JP | 3rd Nov 1992 |
| 150.22.96.0/19 | 8.2k | APNIC | JP | 3rd Nov 1992 |
| 150.222.0.0/16 | 65.5k | ARIN | US | 27th Dec 2017 |
| 150.225.0.0/16 | 65.5k | ARIN | US | 5th Aug 1991 |
| 150.233.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.234.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.235.0.0/16 | 65.5k | ARIN | US | 9th Aug 1991 |
| 150.237.112.0/21 | 2k | RIPE NCC |  NL | 12th Aug 1991 |
| 150.237.120.0/22 | 1k | RIPE NCC | NL | 12th Aug 1991 |
| 150.237.124.0/23 | 512 | RIPE NCC | NL | 12th Aug 1991 |
| 150.237.126.0/23 | 512 | RIPE NCC |  PT | 12th Aug 1991 |
| 150.237.128.0/17 | 32.8k | RIPE NCC |  GB | 12th Aug 1991 |
| 150.237.16.0/20 | 4.1k | RIPE NCC | GB | 12th Aug 1991 |
| 150.237.64.0/19 | 8.2k | RIPE NCC | NL | 12th Aug 1991 |
| 150.237.96.0/20 | 4.1k | RIPE NCC | NL | 12th Aug 1991 |
| 150.24.0.0/16 | 65.5k | APNIC | JP | 7th Jun 1996 |
| 150.242.0.0/22 | 1k | APNIC |  CN | 1st Jul 2014 |
| 150.242.112.0/22 | 1k | APNIC | CN | 3rd Jul 2014 |
| 150.242.116.0/22 | 1k | APNIC | CN | 3rd Jul 2014 |
| 150.242.120.0/22 | 1k | APNIC | CN | 3rd Jul 2014 |
| 150.242.124.0/22 | 1k | APNIC |  HK | 3rd Jul 2014 |
| 150.242.152.0/22 | 1k | APNIC | CN | 4th Jul 2014 |
| 150.242.160.0/22 | 1k | APNIC | CN | 4th Jul 2014 |
| 150.242.164.0/22 | 1k | APNIC | CN | 4th Jul 2014 |
| 150.242.178.0/23 | 512 | APNIC |  ID | 28th Dec 2023 |
| 150.242.188.0/22 | 1k | APNIC | CN | 7th Jul 2014 |
| 150.242.192.0/22 | 1k | APNIC | CN | 7th Jul 2014 |
| 150.242.224.0/22 | 1k | APNIC | CN | 8th Jul 2014 |
| 150.242.240.0/22 | 1k | APNIC | CN | 8th Jul 2014 |