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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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
85,536 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 203.25.135.0/24 | 256 | APNIC |  CN | 14th Apr 2011 |
| 203.25.138.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.147.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.150.0/24 | 256 | APNIC |  AU | 21st Mar 1996 |
| 203.25.153.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.154.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.25.161.0/24 | 256 | APNIC |  BD | 4th Sept 2025 |
| 203.25.162.0/24 | 256 | APNIC |  US | 25th Mar 1996 |
| 203.25.164.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.166.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.170.0/23 | 512 | APNIC | AU | 26th Mar 1996 |
| 203.25.174.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.25.176.0/24 | 256 | APNIC | AU | 26th Mar 1996 |
| 203.25.180.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.182.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.183.0/24 | 256 | APNIC | AU | 26th Mar 1996 |
| 203.25.19.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.191.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.194.0/24 | 256 | APNIC | AU | 28th Mar 1996 |
| 203.25.199.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.20.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.25.200.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.202.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.25.226.0/24 | 256 | APNIC | AU | 29th Mar 1996 |
| 203.25.229.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.23.0/24 | 256 | APNIC |  NZ | 5th Mar 1996 |
| 203.25.235.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.236.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.24.0/23 | 512 | APNIC | AU | 5th Mar 1996 |
| 203.25.242.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.249.0/24 | 256 | APNIC | AU | 2nd Apr 1996 |
| 203.25.250.0/24 | 256 | APNIC | AU | 2nd Apr 1996 |
| 203.25.251.0/24 | 256 | APNIC | AU | 2nd Apr 1996 |
| 203.25.252.0/24 | 256 | APNIC | AU | 2nd Apr 1996 |
| 203.25.254.0/23 | 512 | APNIC | AU | 2nd Apr 1996 |
| 203.25.46.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.47.0/24 | 256 | APNIC | AU | 8th Mar 1996 |
| 203.25.64.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.25.91.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.25.96.0/24 | 256 | APNIC | AU | 12th Mar 1996 |
| 203.25.99.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.252.24.0/23 | 512 | APNIC |  KR | 29th Sept 1996 |
| 203.252.26.0/24 | 256 | APNIC | KR | 29th Sept 1996 |
| 203.252.28.0/22 | 1k | APNIC | KR | 29th Sept 1996 |
| 203.253.112.0/20 | 4.1k | APNIC | KR | 29th Sept 1996 |
| 203.253.233.0/24 | 256 | APNIC | KR | 29th Sept 1996 |
| 203.253.48.0/22 | 1k | APNIC | KR | 29th Sept 1996 |
| 203.253.52.0/22 | 1k | APNIC | KR | 29th Sept 1996 |
| 203.253.56.0/21 | 2k | APNIC | KR | 29th Sept 1996 |
| 203.254.10.0/23 | 512 | APNIC | KR | 29th Sept 1996 |