ASN (autonomous system number)

An Autonomous System Number (ASN) is a unique identifier allocated to each autonomous system (AS) to facilitate its identification by the Internet Assigned Numbers Authority (IANA) and Regional Internet Registries (RIRs). An AS consists of one or more networks operated by one or more entities that present a single, clearly defined routing policy to the internet. ASNs are essential for the operation of the Border Gateway Protocol (BGP), the protocol used for routing internet traffic between different ASes. 

See also: (AS) autonomous system.

Citations:

[1] https://www.cloudflare.com/learning/network-layer/what-is-an-autonomous-system/

[2] https://en.wikipedia.org/wiki/Autonomous_system_(Internet)

[3] https://www.arin.net/resources/guide/asn/

[4] https://www.stackpath.com/edge-academy/what-is-an-autonomous-system-number-asn/

[5] https://www.thousandeyes.com/learning/glossary/as-autonomous-system

[6] https://www.gartner.com/en/information-technology/glossary/asn-autonomous-system-number

[7] https://www.pcmag.com/encyclopedia/term/asn

[8] https://www.techopedia.com/definition/26871/autonomous-system-number-asn