IP & Network guides

An IP address on its own says little about who operates it. These guides explain the systems around it: Autonomous Systems and their numbers, BGP route announcements, and the registry data that links address blocks to organisations.

They focus on practical questions, such as telling a residential connection from a datacenter, grouping abusive traffic by network, and tracing a routing problem to the network that causes it. Registry and geolocation data can lag behind reality, and each article notes where that limits the conclusions you can draw.

To investigate an address yourself, use IP Lookup, ASN Lookup and WHOIS Lookup.