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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,244 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.136.197.0/24 | 256 | ARIN |  US | 7th Jun 1993 |
| 198.136.198.0/24 | 256 | ARIN | US | 7th Jun 1993 |
| 198.136.199.0/24 | 256 | ARIN | US | 7th Jun 1993 |
| 198.136.200.0/24 | 256 | ARIN | US | 7th Jun 1993 |
| 198.136.202.0/24 | 256 | ARIN | US | 8th Jun 1993 |
| 198.136.203.0/24 | 256 | ARIN | US | 8th Jun 1993 |
| 198.136.204.0/24 | 256 | ARIN | US | 8th Jun 1993 |
| 198.136.205.0/24 | 256 | ARIN | US | 8th Jun 1993 |
| 198.136.206.0/24 | 256 | ARIN | US | 8th Jun 1993 |
| 198.136.207.0/24 | 256 | ARIN | US | 9th Jun 1993 |
| 198.136.208.0/24 | 256 | ARIN | US | 9th Jun 1993 |
| 198.136.209.0/24 | 256 | ARIN | US | 9th Jun 1993 |
| 198.136.210.0/24 | 256 | ARIN | US | 9th Jun 1993 |
| 198.136.212.0/24 | 256 | ARIN | US | 9th Jun 1993 |
| 198.136.213.0/24 | 256 | ARIN | US | 10th Jun 1993 |
| 198.136.214.0/24 | 256 | ARIN | US | 10th Jun 1993 |
| 198.136.218.0/24 | 256 | ARIN | US | 10th Jun 1993 |
| 198.136.219.0/24 | 256 | ARIN | US | 10th Jun 1993 |
| 198.136.221.0/24 | 256 | ARIN | US | 11th Jun 1993 |
| 198.136.222.0/24 | 256 | ARIN | US | 11th Jun 1993 |
| 198.136.224.0/24 | 256 | ARIN | US | 11th Jun 1993 |
| 198.136.225.0/24 | 256 | ARIN | US | 11th Jun 1993 |
| 198.136.227.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.136.228.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.136.230.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.136.231.0/24 | 256 | ARIN | US | 15th Jun 1993 |
| 198.136.235.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.136.236.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.136.237.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.136.238.0/24 | 256 | ARIN | US | 7th Jun 2013 |
| 198.136.239.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.136.240.0/24 | 256 | ARIN | US | 18th Jun 1993 |
| 198.136.241.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.136.242.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.136.243.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.136.244.0/24 | 256 | ARIN | US | 21st Jun 1993 |
| 198.136.245.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.246.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.247.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.248.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.249.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.251.0/24 | 256 | ARIN | US | 22nd Jun 1993 |
| 198.136.252.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 198.136.253.0/24 | 256 | ARIN | US | 23rd Jun 1993 |
| 198.136.254.0/24 | 256 | ARIN | US | 25th Jun 1993 |
| 198.137.0.0/21 | 2k | ARIN | US | 15th Apr 1993 |
| 198.137.128.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.129.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.130.0/24 | 256 | ARIN | US | 6th May 1993 |
| 198.137.131.0/24 | 256 | ARIN | US | 6th May 1993 |