AS15251 — GRAND-CENTRAL-STATION

AS15251 announces 3 IPv4 prefixes covering 768 addresses and 0 IPv6 prefixes.

About this network

Two blocks registered to an individual, under netnames that are fifteen-digit numbers.

What it's used for

• A small internet services provider. Three IPv4 /24 prefixes announced from the United States, no IPv6, and two observed BGP neighbours.

Notable

• Two blocks carry netnames made of a three-letter carrier prefix and a fifteen-digit number, and the two numbers share no leading digits despite the same format.
• Those same two blocks are registered to a private individual rather than to any company, which is unusual for space announced by a business.
• The third block's netname joins two company abbreviations to two octets of the address, and its registrant merges two company names into one string.
• Six of nine sampled addresses answered, each combining a network number with the last octet under the provider's own domain.
• The two blocks that answered use different network numbers in those labels, so the scheme counts networks rather than describing them.

Interesting

• A fifteen-digit netname is an account or order number from a carrier's billing system. It identifies the assignment perfectly inside that system and means nothing outside it, which is the recurring failure of these labels: they are written for the issuer, not the reader.
• Space registered to a person and announced by a company is a small operator that never separated the two. It works until the registration needs to be transferred, at which point the registry has no company to transfer it from.
• Numbering networks in reverse names rather than naming them is compact and stable, and it tells an outsider only how many networks there are.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 12.49.56.0/24
• 63.166.183.0/24
• 65.166.22.0/24

Upstream networks

• AS174 Cogent Communications, LLC
• AS7018 AT&T Enterprises, LLC

Adjacent networks

• AS174 Cogent Communications, LLC
• AS7018 AT&T Enterprises, LLC

Routing security

• RPKI: 0 valid, 0 invalid and 3 not-found announcements; 0 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 4 route objects.
• Listed in as-sets: AS-SLF-13760-DOWNSTREAM.