AS4237 CSC-IGN-FTW-AS4237
AS4237 is not on Fraudex's VPN, proxy and datacenter list, so its IPs are treated like ordinary home, mobile or business connections. A single address can still be flagged if it is a Tor exit relay.
Check an IP from AS4237
Look up any address in real time with the free IP checker, or from your own code:
curl "https://fraudex.xyz/api/check?ip=20.137.0.0" \ -H "X-API-Key: fx_your_key"
The answer includes the network (AS4237), the country and a VPN, proxy, Tor and bot verdict, in under a millisecond. Plans start at $40 for 30 days of unlimited lookups.
IPv4 ranges announced by AS4237
| First IP | Last IP | CIDR | Addresses |
|---|---|---|---|
| 20.137.0.0 | 20.137.7.255 | 20.137.0.0/21 | 2,048 |
| 20.137.12.0 | 20.137.15.255 | 20.137.12.0/22 | 1,024 |
| 20.137.176.0 | 20.137.191.255 | 20.137.176.0/20 | 4,096 |
| 20.137.216.0 | 20.137.216.255 | 20.137.216.0/24 | 256 |
| 20.137.240.0 | 20.137.255.255 | 20.137.240.0/20 | 4,096 |
| 20.139.6.0 | 20.139.6.255 | 20.139.6.0/24 | 256 |
| 20.148.32.0 | 20.148.63.255 | 20.148.32.0/19 | 8,192 |
| 20.148.96.0 | 20.148.191.255 | 20.148.96.0/19, 20.148.128.0/18 | 24,576 |
| 20.148.240.0 | 20.148.255.255 | 20.148.240.0/20 | 4,096 |
| 20.156.169.0 | 20.156.169.255 | 20.156.169.0/24 | 256 |
Questions about AS4237
Is AS4237 a VPN or hosting network?
Fraudex does not list AS4237 (CSC-IGN-FTW-AS4237) as a VPN, proxy or hosting network. Its addresses are treated as regular traffic, apart from any Tor exit relays.
Which country is AS4237 registered in?
AS4237 is registered in United States. Individual addresses can be used elsewhere, so check the IP itself when location matters.
How many IP addresses does AS4237 have?
It announces 10 IPv4 ranges with 48,896 addresses in total.
How do I block traffic from AS4237?
Blocking a whole network by number goes stale as ranges change hands. It is more reliable to check each visitor's IP when they sign up, log in or pay: the Fraudex API returns the network and a VPN and bot verdict, so you can block, challenge or just log flagged traffic. See why an IP blocking API pays for itself.