Network · AS21054

AS21054 Natwest Markets PLC

AS21054 (Natwest Markets PLC) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Network check ASN

AS21054

OwnerNatwest Markets PLC
KindInternet service provider
Servers, not peopleno
IPv4 addresses60,672
IPv4 ranges21
IPv6 ranges0

Risk score0

Nothing suspicious found.

Largest IPv4 ranges

155.136.64.0/18
155.136.160.0/19
155.136.0.0/19
155.136.32.0/20
155.136.240.0/20
155.136.208.0/20
155.136.128.0/20
155.136.48.0/21
155.136.152.0/21
155.136.60.0/22
155.136.236.0/22
155.136.204.0/22

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

Check an IP address →

Detect it in code

Spot AS21054 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 AS21054

Is AS21054 a datacenter or VPN network?

AS21054 (Natwest Markets PLC) looks like an internet service provider, so its addresses are mostly real home, business or mobile connections.

Who owns AS21054?

AS21054 is registered to Natwest Markets PLC. It announces about 60,672 IPv4 addresses.

How do I detect traffic from AS21054?

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.