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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 |
|---|---|---|---|---|
| 203.4.180.0/24 | 256 | APNIC |  CN | 14th Apr 2011 |
| 203.4.181.0/24 | 256 | APNIC |  AU | 15th Apr 1994 |
| 203.4.185.0/24 | 256 | APNIC | AU | 19th Apr 1994 |
| 203.4.186.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.4.204.0/24 | 256 | APNIC | AU | 22nd Apr 1994 |
| 203.4.205.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.4.208.0/22 | 1k | APNIC | CN | 14th Apr 2011 |
| 203.4.227.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.4.230.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.4.240.0/21 | 2k | APNIC | AU | 27th Apr 1994 |
| 203.5.11.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.114.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.118.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.119.0/24 | 256 | APNIC | AU | 9th Jun 1994 |
| 203.5.120.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.14.0/23 | 512 | APNIC |  US | 6th May 1994 |
| 203.5.160.0/21 | 2k | APNIC | AU | 20th Jun 1994 |
| 203.5.172.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.18.0/24 | 256 | APNIC | AU | 19th May 1994 |
| 203.5.180.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.182.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.185.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.186.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.188.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.190.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.193.0/24 | 256 | APNIC | AU | 24th Jun 1994 |
| 203.5.195.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.21.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.211.0/24 | 256 | APNIC | AU | 30th Jun 1994 |
| 203.5.214.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.218.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.22.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.220.0/22 | 1k | APNIC | AU | 9th Nov 2007 |
| 203.5.224.0/20 | 4.1k | APNIC | AU | 8th Jul 1994 |
| 203.5.240.0/22 | 1k | APNIC | AU | 8th Jul 1994 |
| 203.5.25.0/24 | 256 | APNIC | AU | 19th May 1994 |
| 203.5.4.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.40.0/22 | 1k | APNIC | AU | 27th Sept 2007 |
| 203.5.44.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.45.0/24 | 256 | APNIC | AU | 27th Sept 2007 |
| 203.5.46.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.52.0/22 | 1k | APNIC | CN | 14th Apr 2011 |
| 203.5.56.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.60.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.7.0/24 | 256 | APNIC | CN | 14th Apr 2011 |
| 203.5.73.0/24 | 256 | APNIC | AU | 27th May 1994 |
| 203.5.8.0/23 | 512 | APNIC | CN | 14th Apr 2011 |
| 203.5.96.0/21 | 2k | APNIC | AU | 27th May 1994 |
| 203.55.115.0/24 | 256 | APNIC | AU | 9th Dec 1996 |
| 203.55.118.0/24 | 256 | APNIC |  TW | 27th Jun 2019 |