Network · AS21589

AS21589 City of San Jose

AS21589 (City of San Jose) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS21589

OwnerCity of San Jose
KindInternet service provider
Servers, not peopleno
IPv4 addresses10,752
IPv4 ranges18
IPv6 ranges1

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

156.39.48.0/21
156.39.136.0/21
156.39.64.0/22
156.39.0.0/22
156.39.68.0/23
156.39.62.0/23
156.39.12.0/23
156.39.10.0/23
156.39.99.0/24
156.39.73.0/24
156.39.60.0/24
156.39.5.0/24

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

Check an IP address →

Detect it in code

Spot AS21589 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 AS21589

Is AS21589 a datacenter or VPN network?

AS21589 (City of San Jose) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS21589?

AS21589 is registered to City of San Jose. It announces about 10,752 IPv4 addresses.

How do I detect traffic from AS21589?

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.