Network · AS16503

AS16503 Zayo Bandwidth

AS16503 (Zayo Bandwidth) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS16503

  • OwnerZayo Bandwidth
  • KindInternet service provider
  • Servers, not peopleno
  • IPv4 addresses20,224
  • IPv4 ranges11
  • IPv6 ranges0
Risk score0

Nothing suspicious found.

Largest IPv4 ranges

  • 66.45.192.0/19
  • 216.178.48.0/20
  • 64.20.96.0/21
  • 64.20.112.0/21
  • 64.20.124.0/22
  • 64.20.108.0/22
  • 64.20.122.0/23
  • 64.20.104.0/23
  • 64.20.121.0/24
  • 64.20.107.0/24
  • 64.124.127.0/24

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

Check an IP address →

Detect it in code

Spot AS16503 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 AS16503

Is AS16503 a datacenter or VPN network?

AS16503 (Zayo Bandwidth) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS16503?

AS16503 is registered to Zayo Bandwidth. It announces about 20,224 IPv4 addresses.

How do I detect traffic from AS16503?

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.