Network · AS1221

AS1221 Telstra Limited

AS1221 (Telstra Limited) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS1221

  • OwnerTelstra Limited
  • KindInternet service provider
  • Servers, not peopleno
  • IPv4 addresses13,387,776
  • IPv4 ranges242
  • IPv6 ranges2
Risk score0

Nothing suspicious found.

Largest IPv4 ranges

  • 1.128.0.0/11
  • 58.160.0.0/12
  • 124.176.0.0/12
  • 121.208.0.0/12
  • 101.176.0.0/12
  • 60.224.0.0/13
  • 203.40.0.0/13
  • 120.144.0.0/13
  • 110.144.0.0/13
  • 101.168.0.0/13
  • 1.120.0.0/13
  • 203.48.0.0/14

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

Check an IP address →

Detect it in code

Spot AS1221 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 AS1221

Is AS1221 a datacenter or VPN network?

AS1221 (Telstra Limited) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS1221?

AS1221 is registered to Telstra Limited. It announces about 13,387,776 IPv4 addresses.

How do I detect traffic from AS1221?

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.