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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,041 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 161.199.96.0/21 | 2k | ARIN |  US | 29th Jan 1993 |
| 161.20.0.0/16 | 65.5k | RIPE NCC |  CH | 28th Apr 1992 |
| 161.201.0.0/16 | 65.5k | ARIN | US | 29th Jan 1993 |
| 161.204.0.0/16 | 65.5k | ARIN | US | 9th Feb 1993 |
| 161.210.100.0/22 | 1k | ARIN | US | 13th Jan 2026 |
| 161.210.104.0/22 | 1k | ARIN | US | 15th May 2026 |
| 161.210.112.0/20 | 4.1k | ARIN | US | 18th Feb 1993 |
| 161.210.16.0/20 | 4.1k | ARIN | US | 18th Feb 1993 |
| 161.210.160.0/20 | 4.1k | ARIN | US | 18th Feb 1993 |
| 161.210.176.0/21 | 2k | ARIN | US | 18th Feb 1993 |
| 161.210.184.0/22 | 1k | ARIN | US | 18th Feb 1993 |
| 161.210.190.0/23 | 512 | ARIN | US | 18th Feb 1993 |
| 161.210.2.0/23 | 512 | ARIN | US | 18th Feb 1993 |
| 161.210.32.0/21 | 2k | ARIN | US | 18th Feb 1993 |
| 161.210.40.0/22 | 1k | ARIN | US | 18th Feb 1993 |
| 161.210.44.0/23 | 512 | ARIN | US | 18th Feb 1993 |
| 161.210.46.0/24 | 256 | ARIN | US | 13th Jan 2026 |
| 161.210.48.0/20 | 4.1k | ARIN | US | 18th Feb 1993 |
| 161.210.64.0/20 | 4.1k | ARIN | US | 18th Feb 1993 |
| 161.210.8.0/21 | 2k | ARIN | US | 18th Feb 1993 |
| 161.210.80.0/21 | 2k | ARIN | US | 18th Feb 1993 |
| 161.210.88.0/23 | 512 | ARIN | US | 18th Feb 1993 |
| 161.210.90.0/24 | 256 | ARIN | US | 18th Feb 2026 |
| 161.211.0.0/16 | 65.5k | ARIN | US | 18th Feb 1993 |
| 161.218.0.0/16 | 65.5k | RIPE NCC |  DE | 1st Sept 1993 |
| 161.219.0.0/16 | 65.5k | ARIN | US | 1st Mar 1993 |
| 161.233.0.0/16 | 65.5k | ARIN | US | 22nd Mar 1993 |
| 161.236.0.0/16 | 65.5k | ARIN | US | 23rd Mar 1993 |
| 161.237.0.0/16 | 65.5k | ARIN | US | 23rd Mar 1993 |
| 161.240.0.0/16 | 65.5k | ARIN | US | 27th Mar 1993 |
| 161.244.0.0/16 | 65.5k | ARIN | US | 30th Mar 1993 |
| 161.245.0.0/16 | 65.5k | ARIN | US | 30th Mar 1993 |
| 161.248.104.0/24 | 256 | APNIC |  MN | 6th Jan 2025 |
| 161.248.107.0/24 | 256 | APNIC |  ID | 8th Jan 2025 |
| 161.248.110.0/23 | 512 | APNIC |  CN | 7th Jan 2025 |
| 161.248.126.0/24 | 256 | APNIC |  PH | 8th Jan 2025 |
| 161.248.16.0/23 | 512 | APNIC |  BD | 23rd Dec 2024 |
| 161.248.195.0/24 | 256 | APNIC | ID | 16th Jan 2025 |
| 161.248.196.0/23 | 512 | APNIC |  VN | 16th Jan 2025 |
| 161.248.20.0/23 | 512 | APNIC | CN | 23rd Dec 2024 |
| 161.248.207.0/24 | 256 | APNIC | ID | 20th Jan 2025 |
| 161.248.214.0/23 | 512 | APNIC |  SG | 19th Jan 2025 |
| 161.248.240.0/24 | 256 | APNIC | ID | 21st Jan 2025 |
| 161.248.42.0/23 | 512 | APNIC | CN | 26th Dec 2024 |
| 161.248.48.0/23 | 512 | APNIC |  IN | 26th Dec 2024 |
| 161.248.9.0/24 | 256 | APNIC |  MY | 20th Dec 2024 |
| 161.248.92.0/23 | 512 | APNIC | CN | 3rd Jan 2025 |
| 161.25.0.0/16 | 65.5k | LACNIC |  CL | 4th May 1992 |
| 161.26.0.0/16 | 65.5k | ARIN | US | 4th Mar 2015 |
| 161.32.32.0/19 | 8.2k | ARIN | US | 14th Jun 2019 |