AS15572 — CYBERTRUST former Cybertrust

AS15572 announces 14 IPv4 prefixes covering 4,096 addresses and 1 IPv6 prefixes.

About this network

Three registrant fields hold internal account numbers, prefixed with the word internal.

What it's used for

• A carrier's national arm. Fourteen IPv4 prefixes and one IPv6 /48 announced from the United Kingdom, four thousand addresses, through two observed BGP neighbours.

Notable

• Three blocks list a registrant made of the word internal, a slash, a retired carrier's initials and a long digit string, which reads as an account or ticket reference rather than an owner.
• One block names a law firm followed by a slash, an abbreviation for international, a circuit type and a number, so a customer and the service they bought are both in the registry.
• One netname carries octets that do not match the block it belongs to.
• Blocks are registered to four different national entities of the same group, in four different countries.
• Two blocks' registry lookups failed, so their details are unknown rather than absent.
• Eighteen addresses were queried for reverse DNS and none returned a name.

Interesting

• Internal reference numbers in a public field are a small leak with a long life. They say nothing on their own and everything to anyone who can read that numbering scheme.
• Twelve of the fourteen blocks are /24 prefixes scattered across unrelated ranges, which is the shape of address space accumulated through acquisitions rather than allocated.
• The AS handle states outright that the brand it carries is a former one, which is more honesty than these fields usually contain.

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

Announced prefixes

• 63.80.38.0/24
• 63.80.162.0/24
• 65.202.69.0/24
• 65.202.114.0/24
• 65.205.33.0/24
• 65.207.25.0/24
• 65.246.75.0/24
• 152.180.28.0/24
• 193.41.20.0/23
• 193.41.22.0/24
• 199.219.3.0/24
• 202.125.12.0/23
• 203.166.34.0/24
• 203.166.127.0/24
• 2600:803:1200::/48

Upstream networks

• AS701 Verizon Business
• AS703 Verizon Business

Adjacent networks

• AS701 Verizon Business
• AS703 Verizon Business