Network Overview

ASNAS3999
OrganizationThe Pennsylvania State University
Announced IPv4 ranges9
Total IPv4 addresses443,904

Sample IP Ranges Announced by AS3999

Range StartRange EndLookup
66.71.0.0 66.71.127.255 Details →
75.102.64.0 75.102.127.255 Details →
104.38.0.0 104.39.255.255 Details →
128.118.0.0 128.118.255.255 Details →
130.203.0.0 130.203.255.255 Details →
146.186.0.0 146.186.255.255 Details →

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 AS3999?

AS3999 is the autonomous system operated by The Pennsylvania State University, announcing 9 IPv4 ranges (443,904 addresses).

Who operates AS3999?

The Pennsylvania State University. 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 AS3999?

Enter the IP into our free IP lookup - the result shows the ASN, operator, geolocation, and VPN/datacenter flags.