Glossary · Networking
ASN
An autonomous system number identifies the network that owns a block of IP addresses, and it is how sites tell a home connection from a data center.
An ASN is the identifier for a network on the global routing table. Every public IP address belongs to an autonomous system, a Comcast, a Hetzner, a Vodafone, and the ASN is the label that ties the address to its owner. It is administrative plumbing that happens to be the most important fact about a proxy address.
The reason is classification. When a site decides whether an address looks residential or hosted, it is really looking up the ASN and checking what kind of organisation owns it. A hosting company's ASN flags a datacenter proxy instantly; a consumer ISP's ASN is what gives residential and ISP proxies their cover.
Because the ASN, not the individual address, carries the reputation, rotating to a new IP within the same flagged network changes nothing. The network is the unit of trust, which is why serious measurement of a proxy pool starts by counting how it spreads across ASNs.
How HProxy handles it
We publish per-ASN liveness because the autonomous system is the real unit of trust, a claim about a network only means something broken down to the operators inside it.
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