Network · AS5517

AS5517 CSL Computer Service Langenbach GmbH

AS5517 (CSL Computer Service Langenbach GmbH) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS5517

OwnerCSL Computer Service Langenbach GmbH
KindInternet service provider
Servers, not peopleno
IPv4 addresses139,264
IPv4 ranges3
IPv6 ranges1

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

194.245.0.0/16
159.25.0.0/16
194.176.0.0/19

Ranges and owner from DB-IP (CC BY 4.0), updated 2026-10-21.

Check an IP address →

Detect it in code

Spot AS5517 traffic at signup.

Send the visitor's IP. The response includes the ASN, the owner and flags.hosting.

curl https://veqen-app.com/v1/ip/check \
  -H "Authorization: Bearer $VEQEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"ip": "203.0.113.7"}'

import os, requests

r = requests.post(
    "https://veqen-app.com/v1/ip/check",
    headers={"Authorization": f"Bearer {os.environ['VEQEN_API_KEY']}"},
    json={"ip": "203.0.113.7"},
    timeout=10,
)
result = r.json()
print(result["risk"]["verdict"], result["risk"]["reasons"])

const res = await fetch("https://veqen-app.com/v1/ip/check", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.VEQEN_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({"ip": "203.0.113.7"}),
});
const result = await res.json();
console.log(result.risk.verdict, result.risk.reasons);

Questions

About AS5517

Is AS5517 a datacenter or VPN network?

AS5517 (CSL Computer Service Langenbach GmbH) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS5517?

AS5517 is registered to CSL Computer Service Langenbach GmbH. It announces about 139,264 IPv4 addresses.

How do I detect traffic from AS5517?

Call the Veqen IP check with the visitor's address. The response includes the ASN, the owner and whether the network is a datacenter, VPN network, relay or ISP.