Network Overview
| ASN | AS42081 |
| Organization | European Centre for Medium-Range Weather Forecasts (ECMWF) |
| Announced IPv4 ranges | 5 |
| Total IPv4 addresses | 27,648 |
Sample IP Ranges Announced by AS42081
| Range Start | Range End | Lookup |
|---|---|---|
77.83.224.0 |
77.83.226.255 |
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136.156.32.0 |
136.156.35.255 |
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136.156.40.0 |
136.156.47.255 |
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136.156.128.0 |
136.156.156.255 |
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136.156.192.0 |
136.156.255.255 |
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What Is an Autonomous System?
An autonomous system (AS) is a collection of IP networks operated by a single organization - an ISP, cloud provider, enterprise, or university - that shares a common routing policy. Each AS is identified by a unique AS number (ASN) and exchanges routing information with other systems using the BGP protocol.
Knowing which ASN an IP belongs to reveals who actually operates the network behind it - useful for fraud analysis, traffic quality assessment, and abuse investigation. Use the IP lookup tool to find the ASN for any address.
Frequently Asked Questions
What is AS42081?
AS42081 is the autonomous system operated by European Centre for Medium-Range Weather Forecasts (ECMWF), announcing 5 IPv4 ranges (27,648 addresses).
Who operates AS42081?
European Centre for Medium-Range Weather Forecasts (ECMWF). An autonomous system is a network under a single administrative entity that exchanges routes with other networks via BGP.
How do I check if an IP belongs to AS42081?
Enter the IP into our free IP lookup - the result shows the ASN, operator, geolocation, and VPN/datacenter flags.