AS15725 — IKS

AS15725 announces 4 IPv4 prefixes covering 4,608 addresses and 17 IPv6 prefixes.

About this network

Nineteen IPv6 routes for four IPv4 ones, announced as a staircase that doubles at every step.

What it's used for

• A regional provider. Four IPv4 prefixes and nineteen IPv6 prefixes announced from Germany, four thousand six hundred and eight addresses, across five observed BGP neighbours.

Notable

• The IPv6 announcements run through /48, /47, /46, /45, /44, /43, /42, /41, /40 and /39, each step twice the size of the one before it.
• That sequence is what covering a range with edges that do not fall on one block boundary produces: the largest piece that fits is taken at each point until the range is tiled.
• Nearly five times as many IPv6 routes as IPv4 ones is the reverse of the usual ratio.
• The netnames carry a country code, the brand and a city, with three of the four blocks sharing a single allocation date and the fourth filed fifteen years later.
• The one answering address puts the four octets hyphenated in front of a label for the network, then the company domain with the city hyphenated into it.
• Twelve addresses were queried and one returned a name.

Interesting

• The same doubling staircase appears on an energy utility elsewhere in this range. It is not a habit of one operator but a property of the arithmetic, and any network announcing part of an allocation produces one.
• A city inside both the netname and the domain is a provider that has never needed to be anywhere else.

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

Announced prefixes

• 185.98.236.0/22
• 217.17.192.0/21
• 217.17.200.0/22
• 217.17.204.0/23
• 2001:4bd8::/41
• 2001:4bd8:53::/48
• 2001:4bd8:54::/46
• 2001:4bd8:58::/45
• 2001:4bd8:60::/43
• 2001:4bd8:80::/41
• 2001:4bd8:100::/40
• 2001:4bd8:200::/39
• 2001:4bd8:400::/38
• 2001:4bd8:800::/37
• 2001:4bd8:1000::/36
• 2001:4bd8:2000::/35
• 2001:4bd8:4000::/34
• 2001:4bd8:8000::/33
• 2001:4bd9::/32
• 2001:4bda::/31
• 2001:4bdc::/30

Upstream networks

• AS199284 Thueringer Netkom GmbH
• AS196714 Thueringer Netkom GmbH
• AS8881 1&1 Versatel GmbH

Downstream networks

• AS49885 INTERSHOP Communications AG
• AS204052 Jenoptik AG

Adjacent networks

• AS199284 Thueringer Netkom GmbH
• AS49885 INTERSHOP Communications AG
• AS196714 Thueringer Netkom GmbH
• AS8881 1&1 Versatel GmbH
• AS204052 Jenoptik AG