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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 150.242.28.0/22 | 1k | APNIC |  CN | 2nd Jul 2014 |
| 150.242.4.0/22 | 1k | APNIC | CN | 1st Jul 2014 |
| 150.242.44.0/22 | 1k | APNIC | CN | 2nd Jul 2014 |
| 150.242.48.0/22 | 1k | APNIC | CN | 2nd Jul 2014 |
| 150.242.52.0/22 | 1k | APNIC | CN | 2nd Jul 2014 |
| 150.242.8.0/22 | 1k | APNIC | CN | 1st Jul 2014 |
| 150.242.92.0/22 | 1k | APNIC | CN | 3rd Jul 2014 |
| 150.247.128.0/17 | 32.8k | ARIN |  US | 5th Aug 1991 |
| 150.247.48.0/20 | 4.1k | ARIN | US | 5th Aug 1991 |
| 150.247.96.0/19 | 8.2k | ARIN | US | 5th Aug 1991 |
| 150.248.0.0/16 | 65.5k | APNIC | CN | 5th Aug 1991 |
| 150.25.0.0/16 | 65.5k | APNIC |  JP | 31st Mar 1997 |
| 150.251.16.0/20 | 4.1k | RIPE NCC | US | 19th Aug 1991 |
| 150.251.192.0/20 | 4.1k | RIPE NCC | US | 19th Aug 1991 |
| 150.251.208.0/20 | 4.1k | RIPE NCC |  GB | 19th Aug 1991 |
| 150.251.248.0/22 | 1k | RIPE NCC |  FR | 19th Aug 1991 |
| 150.251.48.0/21 | 2k | RIPE NCC |  NL | 19th Aug 1991 |
| 150.251.56.0/23 | 512 | RIPE NCC |  CH | 19th Aug 1991 |
| 150.251.60.0/23 | 512 | RIPE NCC | NL | 19th Aug 1991 |
| 150.251.62.0/23 | 512 | RIPE NCC | NL | 19th Aug 1991 |
| 150.252.112.0/20 | 4.1k | ARIN | US | 19th Aug 1991 |
| 150.27.0.0/16 | 65.5k | APNIC | JP | 29th Dec 1992 |
| 150.28.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.33.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.34.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.36.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.4.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.40.0.0/18 | 16.4k | APNIC | JP | 6th Apr 1995 |
| 150.40.64.0/21 | 2k | APNIC | JP | 6th Apr 1995 |
| 150.40.72.0/21 | 2k | ARIN | US | 26th Jun 2024 |
| 150.40.80.0/20 | 4.1k | ARIN | US | 26th Jun 2024 |
| 150.44.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.45.0.0/16 | 65.5k | APNIC | JP | 23rd Jun 1992 |
| 150.48.192.0/18 | 16.4k | APNIC | JP | 4th Mar 1993 |
| 150.50.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.51.0.0/16 | 65.5k | APNIC | JP | 4th Mar 1993 |
| 150.53.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.58.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.6.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.62.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.64.0.0/16 | 65.5k | APNIC | JP | 2nd Sept 1992 |
| 150.68.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.72.0.0/14 | 262k | APNIC | JP | 3rd Nov 1992 |
| 150.76.0.0/14 | 262k | APNIC | JP | 23rd Mar 1993 |
| 150.8.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.80.0.0/16 | 65.5k | APNIC | JP | 1st Apr 1992 |
| 150.81.0.0/16 | 65.5k | APNIC | JP | 31st Mar 1997 |
| 150.85.0.0/16 | 65.5k | APNIC | JP | 26th Apr 1994 |
| 150.88.0.0/16 | 65.5k | APNIC | JP | 10th Feb 1992 |
| 150.92.0.0/16 | 65.5k | APNIC | JP | 22nd May 1996 |