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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 163.190.0.0/16 | 65.5k | ARIN |  US | 13th Aug 1992 |
| 163.217.0.0/16 | 65.5k | APNIC |  JP | 12th Apr 1993 |
| 163.219.0.0/16 | 65.5k | APNIC | JP | 12th Apr 1993 |
| 163.220.160.0/20 | 4.1k | APNIC | JP | 2nd Apr 1993 |
| 163.223.100.0/24 | 256 | APNIC |  ID | 13th Mar 2025 |
| 163.223.124.0/23 | 512 | APNIC |  CN | 17th Mar 2025 |
| 163.223.148.0/23 | 512 | APNIC |  TL | 19th Mar 2025 |
| 163.223.168.0/23 | 512 | APNIC |  IN | 20th Mar 2025 |
| 163.223.170.0/23 | 512 | APNIC | IN | 20th Mar 2025 |
| 163.223.188.0/23 | 512 | APNIC |  VN | 24th Mar 2025 |
| 163.223.201.0/24 | 256 | APNIC |  PH | 26th Mar 2025 |
| 163.223.222.0/23 | 512 | APNIC | CN | 1st Apr 2025 |
| 163.223.236.0/23 | 512 | APNIC |  SG | 4th Apr 2025 |
| 163.223.242.0/23 | 512 | APNIC | IN | 4th Apr 2025 |
| 163.223.248.0/23 | 512 | APNIC |  TW | 7th Apr 2025 |
| 163.223.252.0/23 | 512 | APNIC | IN | 8th Apr 2025 |
| 163.223.28.0/23 | 512 | APNIC | CN | 6th Mar 2025 |
| 163.223.32.0/23 | 512 | APNIC | CN | 6th Mar 2025 |
| 163.223.36.0/24 | 256 | APNIC |  AF | 7th Mar 2025 |
| 163.223.38.0/23 | 512 | APNIC |  BD | 7th Mar 2025 |
| 163.223.71.0/24 | 256 | APNIC | ID | 11th Mar 2025 |
| 163.223.72.0/23 | 512 | APNIC |  HK | 11th Mar 2025 |
| 163.223.82.0/23 | 512 | APNIC | IN | 11th Mar 2025 |
| 163.223.94.0/23 | 512 | APNIC |  KR | 12th Mar 2025 |
| 163.223.97.0/24 | 256 | APNIC | ID | 13th Mar 2025 |
| 163.224.0.0/16 | 65.5k | APNIC | JP | 16th Apr 1993 |
| 163.227.1.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.125.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.166.0/24 | 256 | APNIC | ID | 27th Apr 2025 |
| 163.227.17.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.201.0/24 | 256 | APNIC | ID | 1st May 2025 |
| 163.227.204.0/24 | 256 | APNIC | IN | 1st May 2025 |
| 163.227.209.0/24 | 256 | APNIC | SG | 2nd May 2025 |
| 163.227.210.0/23 | 512 | APNIC | IN | 1st May 2025 |
| 163.227.221.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.222.0/23 | 512 | APNIC | IN | 2nd May 2025 |
| 163.227.225.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.226.0/23 | 512 | APNIC | JP | 16th Apr 1993 |
| 163.227.233.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.234.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.240.0/24 | 256 | APNIC | PH | 6th May 2025 |
| 163.227.241.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.242.0/23 | 512 | APNIC | JP | 16th Apr 1993 |
| 163.227.254.0/24 | 256 | APNIC | JP | 16th Apr 1993 |
| 163.227.34.0/23 | 512 | APNIC | CN | 9th Apr 2025 |
| 163.227.4.0/23 | 512 | APNIC | JP | 8th Apr 2025 |
| 163.227.49.0/24 | 256 | APNIC | ID | 11th Apr 2025 |
| 163.227.74.0/23 | 512 | APNIC | CN | 16th Apr 2025 |
| 163.227.76.0/23 | 512 | APNIC | CN | 16th Apr 2025 |
| 163.227.78.0/23 | 512 | APNIC | CN | 16th Apr 2025 |