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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
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Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,493 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 204.124.32.0/19 | 8.2k | ARIN |  US | 17th Aug 1994 |
| 204.124.4.0/22 | 1k | ARIN | US | 30th Sept 1994 |
| 204.124.68.0/22 | 1k | ARIN | US | 6th Oct 1994 |
| 204.124.72.0/22 | 1k | ARIN | US | 6th Oct 1994 |
| 204.124.76.0/22 | 1k | ARIN | US | 10th Oct 1994 |
| 204.124.8.0/23 | 512 | ARIN | US | 4th Oct 1994 |
| 204.124.86.0/24 | 256 | ARIN | US | 11th Oct 1994 |
| 204.124.88.0/22 | 1k | ARIN | US | 10th Mar 2015 |
| 204.124.94.0/24 | 256 | ARIN | US | 14th Oct 1994 |
| 204.125.0.0/16 | 65.5k | ARIN | US | 19th Aug 1994 |
| 204.126.0.0/23 | 512 | ARIN | US | 19th Sept 1994 |
| 204.126.100.0/23 | 512 | ARIN | US | 23rd Nov 1994 |
| 204.126.102.0/23 | 512 | ARIN | US | 30th Nov 1994 |
| 204.126.108.0/23 | 512 | ARIN | US | 7th Dec 1994 |
| 204.126.114.0/23 | 512 | ARIN | US | 18th Sept 2025 |
| 204.126.130.0/23 | 512 | ARIN | US | 29th Dec 1994 |
| 204.126.14.0/23 | 512 | ARIN | US | 13th Oct 1994 |
| 204.126.148.0/23 | 512 | ARIN | US | 16th Jan 1995 |
| 204.126.150.0/23 | 512 | ARIN | US | 24th Jan 1995 |
| 204.126.154.0/23 | 512 | ARIN | US | 26th Jan 1995 |
| 204.126.158.0/23 | 512 | ARIN | US | 27th Jan 1995 |
| 204.126.164.0/23 | 512 | ARIN | US | 30th Jan 1995 |
| 204.126.176.0/23 | 512 | ARIN | US | 8th Feb 1995 |
| 204.126.18.0/23 | 512 | ARIN | US | 24th Mar 2011 |
| 204.126.182.0/23 | 512 | ARIN | US | 21st Feb 1995 |
| 204.126.184.0/23 | 512 | ARIN | US | 24th Feb 1995 |
| 204.126.192.0/23 | 512 | ARIN | US | 28th Feb 1995 |
| 204.126.196.0/23 | 512 | ARIN | US | 1st Mar 1995 |
| 204.126.198.0/23 | 512 | ARIN | US | 3rd Mar 1995 |
| 204.126.202.0/23 | 512 | ARIN | US | 8th Mar 1995 |
| 204.126.214.0/23 | 512 | ARIN | US | 8th Mar 1995 |
| 204.126.216.0/23 | 512 | ARIN | US | 9th Mar 1995 |
| 204.126.220.0/23 | 512 | ARIN | US | 15th Mar 1995 |
| 204.126.226.0/23 | 512 | ARIN | US | 17th Mar 1995 |
| 204.126.228.0/23 | 512 | ARIN | US | 17th Mar 1995 |
| 204.126.232.0/23 | 512 | ARIN | US | 22nd Mar 1995 |
| 204.126.234.0/23 | 512 | ARIN | US | 24th Mar 1995 |
| 204.126.238.0/23 | 512 | ARIN | US | 5th Apr 1995 |
| 204.126.24.0/23 | 512 | ARIN | US | 27th Apr 2020 |
| 204.126.242.0/23 | 512 | ARIN | US | 10th Apr 1995 |
| 204.126.244.0/23 | 512 | ARIN | US | 20th Apr 1995 |
| 204.126.246.0/23 | 512 | ARIN | US | 21st Apr 1995 |
| 204.126.250.0/23 | 512 | ARIN | US | 24th Apr 1995 |
| 204.126.254.0/23 | 512 | ARIN | US | 9th Jul 2025 |
| 204.126.28.0/23 | 512 | ARIN | US | 25th Oct 1994 |
| 204.126.30.0/23 | 512 | ARIN | US | 25th Oct 1994 |
| 204.126.32.0/20 | 4.1k | ARIN | US | 19th Aug 1994 |
| 204.126.4.0/23 | 512 | ARIN | US | 27th Sept 1994 |
| 204.126.48.0/21 | 2k | ARIN | US | 19th Aug 1994 |
| 204.126.56.0/22 | 1k | ARIN | US | 19th Aug 1994 |