What is ASN?
An Autonomous System Number is the globally unique number used to identify an autonomous system that exchanges internet routes through BGP.
English name, abbreviation and common aliases
- English name: Autonomous System Number
- Abbreviation: ASN
- Common aliases: AS number, Autonomous system identifier
How does ASN work?
Networks advertise IP prefixes and routing paths using the Border Gateway Protocol. The AS path records the sequence of autonomous systems, allowing operators and risk services to infer the network owner and route type.
A concrete example
Two proxy IPs are in different address ranges but are announced by the same hosting ASN. A destination may therefore classify both as coming from the same network operator.
ASN vs. related concepts
An IP address identifies an interface or endpoint. An ASN identifies the routing organization announcing a group of prefixes; IP reputation is a separate risk assessment.
Use cases, benefits and risks
Typical uses include proxy selection, routing diagnostics, session continuity and regional consistency checks. Benefits depend on accurate configuration. Shared infrastructure, stale reputation data, unnecessary rotation and split routing can instead increase failures or expose unexpected signals.
How is ASN related to DuoPlus?
DuoPlus supports per-cloud-phone proxy configuration and network-environment management. Users still need a suitable proxy provider, consistent DNS and application routing, and lawful use; no configuration guarantees a destination’s acceptance.
Frequently asked questions
Is ASN always reliable or available?
It can reveal the routing organization, but not the individual user or exact physical location.
Does this alone make a network trustworthy?
No. Destinations evaluate route ownership, history, configuration, traffic and behavior together.
