Network · AS51887

AS51887 FREQUENTIS COMSOFT GmbH

AS51887 (FREQUENTIS COMSOFT GmbH) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS51887

OwnerFREQUENTIS COMSOFT GmbH
KindInternet service provider
Servers, not peopleno
IPv4 addresses768
IPv4 ranges2
IPv6 ranges0

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

91.221.120.0/23
91.220.159.0/24

Ranges and owner from DB-IP (CC BY 4.0), updated 2026-10-22.

Check an IP address →

Detect it in code

Spot AS51887 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 AS51887

Is AS51887 a datacenter or VPN network?

AS51887 (FREQUENTIS COMSOFT GmbH) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS51887?

AS51887 is registered to FREQUENTIS COMSOFT GmbH. It announces about 768 IPv4 addresses.

How do I detect traffic from AS51887?

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.