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It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today.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 in United States

27,001 blocks match, ordered by prefix.

Allocated but unannounced blocks, 22401 to 22450 of 27001
Prefix	Addresses	Registry	Country	Allocated
2604:c100::/32	4.3B × /64	ARIN	US	10th May 2011
2604:c180::/32	4.3B × /64	ARIN	US	20th May 2013
2604:c1c0::/32	4.3B × /64	ARIN	US	10th Apr 2018
2604:c240::/32	4.3B × /64	ARIN	US	11th Apr 2018
2604:c300::/32	4.3B × /64	ARIN	US	10th May 2011
2604:c3c0::/32	4.3B × /64	ARIN	US	12th Apr 2018
2604:c540::/32	4.3B × /64	ARIN	US	17th Apr 2018
2604:c600::/32	4.3B × /64	ARIN	US	24th Nov 2010
2604:c640::/32	4.3B × /64	ARIN	US	19th Apr 2018
2604:c680::/32	4.3B × /64	ARIN	US	3rd Jun 2013
2604:c740::/32	4.3B × /64	ARIN	US	20th Apr 2018
2604:c780::/32	4.3B × /64	ARIN	US	4th Jun 2013
2604:c940::/32	4.3B × /64	ARIN	US	30th Apr 2018
2604:cc40::/32	4.3B × /64	ARIN	US	9th May 2018
2604:cd80::/32	4.3B × /64	ARIN	US	24th Jun 2013
2604:ce40::/32	4.3B × /64	ARIN	US	10th May 2018
2604:ce80::/32	4.3B × /64	ARIN	US	24th Jun 2013
2604:d080::/32	4.3B × /64	ARIN	US	26th Jun 2013
2604:d100::/32	4.3B × /64	ARIN	US	11th May 2011
2604:d140::/32	4.3B × /64	ARIN	US	16th May 2018
2604:d180::/32	4.3B × /64	ARIN	US	27th Jun 2013
2604:d1c0::/32	4.3B × /64	ARIN	US	16th May 2018
2604:d240::/32	4.3B × /64	ARIN	US	17th May 2018
2604:d280::/32	4.3B × /64	ARIN	US	28th Jun 2013
2604:d380::/32	4.3B × /64	ARIN	US	3rd Jul 2013
2604:d480::/32	4.3B × /64	ARIN	US	30th Jan 2026
2604:d500::/32	4.3B × /64	ARIN	US	13th May 2011
2604:d5c0::/32	4.3B × /64	ARIN	US	29th May 2018
2604:d640::/32	4.3B × /64	ARIN	US	29th May 2018
2604:d740::/32	4.3B × /64	ARIN	US	30th May 2018
2604:d80::/32	4.3B × /64	ARIN	US	23rd Aug 2012
2604:d830::/32	4.3B × /64	ARIN	US	2nd Jul 2026
2604:d860::/32	4.3B × /64	ARIN	US	24th Dec 2025
2604:d940::/32	4.3B × /64	ARIN	US	4th Jun 2018
2604:da0::/32	4.3B × /64	ARIN	US	21st Apr 2025
2604:da40::/32	4.3B × /64	ARIN	US	5th Jun 2018
2604:dac0::/32	4.3B × /64	ARIN	US	5th Jun 2018
2604:db80::/32	4.3B × /64	ARIN	US	2nd Feb 2026
2604:dc40::/32	4.3B × /64	ARIN	US	12th Jun 2018
2604:dcc0::/32	4.3B × /64	ARIN	US	13th Jun 2018
2604:dd00::/32	4.3B × /64	ARIN	US	19th May 2011
2604:dd80::/32	4.3B × /64	ARIN	US	25th Jul 2013
2604:ddc0::/32	4.3B × /64	ARIN	US	20th Jun 2018
2604:de00::/36	268M × /64	ARIN	US	29th Nov 2010
2604:de0::/32	4.3B × /64	ARIN	US	23rd Apr 2025
2604:de40::/32	4.3B × /64	ARIN	US	21st Jun 2018
2604:de80::/32	4.3B × /64	ARIN	US	3rd Feb 2026
2604:dec0::/32	4.3B × /64	ARIN	US	21st Jun 2018
2604:df80::/32	4.3B × /64	ARIN	US	5th Feb 2026
2604:e040::/32	4.3B × /64	ARIN	US	25th Jun 2018