AS15495 — BASF-IT-SERVICES BASF Digital Solutions GmbH

AS15495 announces 10 IPv4 prefixes covering 66,560 addresses and 1 IPv6 prefixes.

About this network

Eight routes tile an entire large range, in every size from /17 down to /24, with one gap.

What it's used for

• A chemical group's technology arm. Ten IPv4 prefixes and one IPv6 /32 announced from Germany, sixty-six thousand addresses, through two observed BGP neighbours.

Notable

• Eight of the ten blocks come from one range and descend by exactly one bit each time: a /17, then a /18, /19, /20, /21, /22, /23 and /24, each covering the half the previous one left.
• The eight together account for all but one /24 of the range. That one is missing, which is why the total falls two hundred and fifty-six addresses short of a full range.
• The remaining two blocks are a /22 and a /24 from unrelated space, one of them named for a subsidiary in a different industry.
• Eighteen addresses were queried for reverse DNS and none returned a name.

Interesting

• A descending staircase like this is what happens when a network reclaims its own range piece by piece. Each announcement covers the largest block it can, so the sizes fall by one bit at every step.
• The missing /24 is the interesting part. Something in that range is routed elsewhere or is not routed at all, and it is the only thing preventing a single announcement replacing all eight.
• Sixty-six thousand addresses behind two upstreams, with nothing published in reverse, is a network built to reach out rather than to be reached.

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

Announced prefixes

• 141.6.0.0/21
• 141.6.8.0/24
• 141.6.10.0/23
• 141.6.12.0/22
• 141.6.16.0/20
• 141.6.32.0/19
• 141.6.64.0/18
• 141.6.128.0/17
• 193.23.152.0/22
• 195.234.178.0/24
• 2a03:5680::/32

Upstream networks

• AS3320 Deutsche Telekom AG
• AS10282 GLOBAL ONE

Adjacent networks

• AS3320 Deutsche Telekom AG
• AS10282 GLOBAL ONE

Routing security

• RPKI: 4 valid, 0 invalid and 0 not-found announcements; 4 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 5 route objects.
• Listed in as-sets: AS-BASF, AS-CTBC-CUSTOMERS86, AS-ECRCCUSTDE, AS-VIAG, AS-VIAG, AS13335:AS-CUSTOMERS, AS3320:AS-DTAG, AS3320:AS-DTAG-V6.