AS5517 — CSL

Network type: hosting

AS5517 announces 3 IPv4 prefixes covering 139,264 addresses and 1 IPv6 prefixes.

About this network

CSL is CSL Computer Service Langenbach GmbH, a German hosting company operating its own datacentre on Hansaallee in Duesseldorf. The company dates to 1972 and has run an internet business since the mid-1990s.

What it's used for

• Managed hosting, root and dedicated servers, private cloud and SSL certificates, all served from CSL's Duesseldorf facility.
• Tens of thousands of domains resolve into this space, the clearest signature of a shared-and-dedicated hosting operator.

Notable

• CSL is also an ICANN-accredited domain registrar, operating the Joker.com registrar brand. That puts registrar, DNS and hosting infrastructure behind the same AS.
• The datacentre is certified by the German Federal Network Agency for its privacy standards, which is part of the pitch: German-hosted, German-regulated.

Interesting

• The low AS number is genuine here rather than a reassignment artifact. CSL has been an internet provider since the mid-1990s, so it belongs to the generation of German operators that got their numbers when the range was still being handed out sequentially.

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

Announced prefixes

• 159.25.0.0/16
• 194.176.0.0/19
• 194.245.0.0/16
• 2a01:4fc0::/34

Upstream networks

• AS8220 COLT Technology Services Group Limited
• AS8881 1&1 Versatel GmbH

Adjacent networks

• AS8220 COLT Technology Services Group Limited
• AS8881 1&1 Versatel GmbH