Network · AS5501

AS5501 Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.

AS5501 (Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS5501

  • OwnerFraunhofer-Gesellschaft zur Foerderung
  • KindInternet service provider
  • Servers, not peopleno
  • IPv4 addresses121,088
  • IPv4 ranges37
  • IPv6 ranges8
Risk score0

Nothing suspicious found.

Largest IPv4 ranges

  • 137.251.0.0/16
  • 129.233.0.0/17
  • 129.233.240.0/20
  • 153.97.0.0/21
  • 153.96.0.0/21
  • 192.44.0.0/22
  • 153.96.220.0/22
  • 153.96.12.0/22
  • 129.233.220.0/22
  • 129.233.204.0/22
  • 153.96.8.0/23
  • 153.96.54.0/23

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

Check an IP address →

Detect it in code

Spot AS5501 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 AS5501

Is AS5501 a datacenter or VPN network?

AS5501 (Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS5501?

AS5501 is registered to Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V.. It announces about 121,088 IPv4 addresses.

How do I detect traffic from AS5501?

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.