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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,248 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 198.202.8.0/21 | 2k | ARIN |  US | 24th Sept 1993 |
| 198.203.128.0/24 | 256 | ARIN | US | 13th Apr 1994 |
| 198.203.129.0/24 | 256 | ARIN | US | 13th Apr 1994 |
| 198.203.130.0/24 | 256 | ARIN | US | 15th Apr 1994 |
| 198.203.133.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.134.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.135.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.137.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.138.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.139.0/24 | 256 | ARIN | US | 18th Apr 1994 |
| 198.203.142.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.143.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.144.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.149.0/24 | 256 | ARIN | US | 2nd Jul 2026 |
| 198.203.151.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.152.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.153.0/24 | 256 | ARIN | US | 20th Apr 1994 |
| 198.203.155.0/24 | 256 | ARIN | US | 21st Apr 1994 |
| 198.203.156.0/22 | 1k | ARIN | US | 21st Apr 1994 |
| 198.203.160.0/22 | 1k | ARIN | US | 25th Apr 1994 |
| 198.203.164.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 198.203.166.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 198.203.167.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 198.203.168.0/24 | 256 | ARIN | US | 25th Apr 1994 |
| 198.203.170.0/24 | 256 | ARIN | US | 27th Apr 1994 |
| 198.203.171.0/24 | 256 | ARIN | US | 27th Apr 1994 |
| 198.203.172.0/24 | 256 | ARIN | US | 27th Apr 1994 |
| 198.203.182.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.183.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.184.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.185.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.188.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.189.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.190.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.192.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.193.0/24 | 256 | ARIN | US | 28th Apr 1994 |
| 198.203.198.0/23 | 512 | RIPE NCC |  SI | 29th Apr 1994 |
| 198.203.206.0/24 | 256 | ARIN | US | 3rd May 1994 |
| 198.203.207.0/24 | 256 | ARIN | US | 3rd May 1994 |
| 198.203.208.0/22 | 1k | ARIN | US | 4th May 1994 |
| 198.203.212.0/24 | 256 | ARIN | US | 4th May 1994 |
| 198.203.214.0/24 | 256 | ARIN | US | 4th May 1994 |
| 198.203.215.0/24 | 256 | ARIN | US | 5th May 1994 |
| 198.203.216.0/24 | 256 | ARIN | US | 5th May 1994 |
| 198.203.217.0/24 | 256 | ARIN | US | 5th May 1994 |
| 198.203.218.0/24 | 256 | ARIN | US | 5th May 1994 |
| 198.203.224.0/24 | 256 | ARIN | US | 6th May 1994 |
| 198.203.225.0/24 | 256 | ARIN | US | 6th May 1994 |
| 198.203.226.0/24 | 256 | ARIN | US | 9th May 1994 |
| 198.203.227.0/24 | 256 | ARIN | US | 10th May 1994 |