Network · AS40271

AS40271 San Francisco Metropolitan Internet Exchange (SFMIX)

AS40271 (San Francisco Metropolitan Internet Exchange (SFMIX)) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS40271

  • OwnerSan Francisco Metropolitan Internet Ex
  • KindInternet service provider
  • Servers, not peopleno
  • IPv4 addresses768
  • IPv4 ranges2
  • IPv6 ranges0
Risk score0

Nothing suspicious found.

Largest IPv4 ranges

  • 149.112.188.0/23
  • 149.112.115.0/24

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

Check an IP address →

Detect it in code

Spot AS40271 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 AS40271

Is AS40271 a datacenter or VPN network?

AS40271 (San Francisco Metropolitan Internet Exchange (SFMIX)) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS40271?

AS40271 is registered to San Francisco Metropolitan Internet Exchange (SFMIX). It announces about 768 IPv4 addresses.

How do I detect traffic from AS40271?

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.