Network · AS43037

AS43037 Seznam.cz, a.s.

AS43037 (Seznam.cz, a.s.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS43037

OwnerSeznam.cz, a.s.
KindInternet service provider
Servers, not peopleno
IPv4 addresses3,072
IPv4 ranges2
IPv6 ranges1

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

77.75.72.0/21
185.66.188.0/22

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

Check an IP address →

Detect it in code

Spot AS43037 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 AS43037

Is AS43037 a datacenter or VPN network?

AS43037 (Seznam.cz, a.s.) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS43037?

AS43037 is registered to Seznam.cz, a.s.. It announces about 3,072 IPv4 addresses.

How do I detect traffic from AS43037?

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.