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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,310 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 199.4.161.0/24 | 256 | ARIN |  US | 18th Aug 2015 |
| 199.4.168.0/21 | 2k | ARIN | US | 7th Dec 1993 |
| 199.4.176.0/22 | 1k | ARIN | US | 7th Dec 1993 |
| 199.4.180.0/22 | 1k | ARIN | US | 8th Dec 1993 |
| 199.4.184.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.185.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.186.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.187.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.188.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.193.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.194.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.196.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.197.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.198.0/24 | 256 | ARIN | US | 8th Dec 1993 |
| 199.4.199.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.200.0/22 | 1k | ARIN | US | 9th Dec 1993 |
| 199.4.204.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.206.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.207.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.208.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.209.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.210.0/24 | 256 | ARIN | US | 9th Dec 1993 |
| 199.4.214.0/24 | 256 | ARIN | US | 10th Dec 1993 |
| 199.4.215.0/24 | 256 | ARIN | US | 10th Dec 1993 |
| 199.4.219.0/24 | 256 | ARIN | US | 10th Dec 1993 |
| 199.4.221.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.222.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.224.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.226.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.228.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.230.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.232.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.234.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.24.0/22 | 1k | ARIN | US | 24th Sept 1993 |
| 199.4.241.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.242.0/23 | 512 | ARIN | US | 13th Dec 1993 |
| 199.4.244.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.245.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.248.0/24 | 256 | ARIN | US | 13th Dec 1993 |
| 199.4.252.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.253.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.254.0/24 | 256 | ARIN | US | 14th Dec 1993 |
| 199.4.8.0/21 | 2k | ARIN | US | 14th Sept 1993 |
| 199.43.1.0/24 | 256 | ARIN |  CA | 5th Jan 1994 |
| 199.43.104.0/22 | 1k | ARIN | US | 2nd Feb 1994 |
| 199.43.110.0/24 | 256 | ARIN | CA | 4th Feb 1994 |
| 199.43.111.0/24 | 256 | ARIN | CA | 9th Feb 1994 |
| 199.43.112.0/24 | 256 | ARIN | CA | 22nd Feb 1994 |
| 199.43.113.0/24 | 256 | ARIN | CA | 6th Jun 1994 |
| 199.43.116.0/24 | 256 | ARIN | CA | 8th Mar 1994 |