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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States
27,001 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.108.226.0/24 | 256 | ARIN |  US | 1st Aug 1991 |
| 192.108.228.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.108.229.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.108.233.0/24 | 256 | ARIN | US | 2nd Aug 1991 |
| 192.108.236.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.237.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.239.0/24 | 256 | ARIN | US | 18th Sept 2015 |
| 192.108.240.0/23 | 512 | ARIN | US | 5th Aug 1991 |
| 192.108.243.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.244.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.245.0/24 | 256 | ARIN | US | 7th Mar 1996 |
| 192.108.246.0/23 | 512 | ARIN | US | 5th Aug 1991 |
| 192.108.248.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.249.0/24 | 256 | ARIN | US | 3rd Feb 1993 |
| 192.108.250.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.251.0/24 | 256 | ARIN | US | 5th Aug 1991 |
| 192.108.252.0/23 | 512 | ARIN | US | 5th Aug 1991 |
| 192.108.3.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.4.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.5.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.6.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.7.0/24 | 256 | ARIN | US | 26th Apr 1991 |
| 192.108.93.0/24 | 256 | ARIN | US | 2nd May 1991 |
| 192.108.94.0/24 | 256 | ARIN | US | 2nd May 1991 |
| 192.108.96.0/24 | 256 | ARIN | US | 6th May 1991 |
| 192.109.110.0/24 | 256 | ARIN | US | 2nd Feb 2022 |
| 192.109.119.0/24 | 256 | ARIN | US | 2nd Feb 2022 |
| 192.109.149.0/24 | 256 | ARIN | US | 18th Jan 2022 |
| 192.109.25.0/24 | 256 | RIPE NCC | US | 12th Nov 2019 |
| 192.110.0.0/24 | 256 | ARIN | US | 14th Apr 2015 |
| 192.110.1.0/24 | 256 | ARIN | US | 22nd May 1991 |
| 192.110.128.0/20 | 4.1k | ARIN | US | 22nd May 1991 |
| 192.110.148.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.110.149.0/24 | 256 | ARIN | US | 14th Jun 1995 |
| 192.110.150.0/23 | 512 | ARIN | US | 21st Jan 2015 |
| 192.110.152.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.110.154.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.110.155.0/24 | 256 | ARIN | US | 17th Mar 2015 |
| 192.110.168.0/24 | 256 | ARIN | US | 13th Aug 1992 |
| 192.110.169.0/24 | 256 | ARIN | US | 23rd Mar 2015 |
| 192.110.2.0/23 | 512 | ARIN | US | 22nd May 1991 |
| 192.110.222.0/24 | 256 | ARIN | US | 17th Mar 2015 |
| 192.110.223.0/24 | 256 | ARIN | US | 22nd May 1991 |
| 192.110.224.0/20 | 4.1k | ARIN | US | 22nd May 1991 |
| 192.110.240.0/21 | 2k | ARIN | US | 22nd May 1991 |
| 192.110.248.0/23 | 512 | ARIN | US | 22nd May 1991 |
| 192.110.250.0/24 | 256 | ARIN | US | 22nd May 1991 |
| 192.110.252.0/24 | 256 | ARIN | US | 30th May 1991 |
| 192.110.253.0/24 | 256 | ARIN | US | 30th May 1991 |
| 192.110.254.0/24 | 256 | ARIN | US | 30th May 1991 |