Network · AS57728

AS57728 CEZNET s.r.o.

AS57728 (CEZNET s.r.o.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS57728

OwnerCEZNET s.r.o.
KindInternet service provider
Servers, not peopleno
IPv4 addresses15,360
IPv4 ranges4
IPv6 ranges3

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

188.122.192.0/19
81.25.16.0/20
109.234.40.0/21
185.255.116.0/22

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

Check an IP address →

Detect it in code

Spot AS57728 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 AS57728

Is AS57728 a datacenter or VPN network?

AS57728 (CEZNET s.r.o.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS57728?

AS57728 is registered to CEZNET s.r.o.. It announces about 15,360 IPv4 addresses.

How do I detect traffic from AS57728?

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.