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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,356 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 205.210.144.0/24 | 256 | ARIN |  CA | 8th Apr 1995 |
| 205.210.145.0/24 | 256 | ARIN |  US | 5th Jan 2012 |
| 205.210.147.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.149.0/24 | 256 | ARIN | US | 22nd Dec 2011 |
| 205.210.151.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.152.0/23 | 512 | ARIN | CA | 8th Apr 1995 |
| 205.210.154.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.155.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.16.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.168.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.169.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.170.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.171.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.172.0/22 | 1k | ARIN | CA | 8th Apr 1995 |
| 205.210.18.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.184.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.185.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.186.0/23 | 512 | ARIN | US | 16th Mar 2012 |
| 205.210.192.0/20 | 4.1k | ARIN | CA | 8th Apr 1995 |
| 205.210.2.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.232.0/23 | 512 | ARIN | US | 8th Apr 1995 |
| 205.210.235.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.24.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.242.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.243.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.244.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.245.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 205.210.247.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.248.0/24 | 256 | ARIN | US | 10th Jan 2012 |
| 205.210.249.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.25.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.250.0/23 | 512 | ARIN | CA | 2nd Apr 1997 |
| 205.210.255.0/24 | 256 | ARIN | US | 23rd Jan 2012 |
| 205.210.26.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.28.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.29.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.3.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.36.0/24 | 256 | ARIN | US | 8th Apr 1995 |
| 205.210.37.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.4.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.40.0/24 | 256 | RIPE NCC |  GB | 8th Apr 1995 |
| 205.210.41.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.44.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.45.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.46.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.47.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.48.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.49.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.5.0/24 | 256 | ARIN | CA | 8th Apr 1995 |
| 205.210.50.0/24 | 256 | ARIN | CA | 8th Apr 1995 |