Editing Autonomous system (Internet) (section)

== AS-SET ==
Autonomous systems can be included in one or more AS-SETs, for example AS-SET of RIPE NCC "AS-12655" has AS1, AS2 and AS3 as its members,<ref>{{Cite web|title=AS-12655 - bgp.he.net|url=https://bgp.he.net/irr/as-set/AS-12655|access-date=2021-10-24|website=bgp.he.net}}</ref> but AS1 is also included in other sets in ARIN (AS-INCAPSULA) and APNIC (AS-IMCL). Another AS-SET sources can be RADB, LEVEL3 ([[tier 1 network]] now called [[Lumen Technologies]]) and also ARIN has ARIN-NONAUTH source of AS-SETs.<ref>{{Cite web|title=IRR explorer|url=https://irrexplorer.nlnog.net/asn/AS1|access-date=2022-01-30|website=irrexplorer.nlnog.net}}</ref> AS-SETs are created by network operators in an [[Internet Routing Registry]] (IRR), like other route objects, and can be included in other AS-SETs and even form cycles.<ref>{{Cite web|title=IRR explorer|url=https://irrexplorer.nlnog.net/as-set/AS-ROSTELECOM|access-date=2022-01-30|website=irrexplorer.nlnog.net}}</ref><ref>{{Cite web|title=IDIDB - Объекты AS-SET|url=https://www.ididb.ru/asset/#AS-ROSTELECOM|access-date=2021-10-24|website=www.ididb.ru}}</ref>

AS-SET names usually start with "AS-", but can also have a hierarchical name. For example, the administrator of AS 64500 may create an AS-SET called "AS64500:AS-UPSTREAMS", to avoid conflict with other similarly named AS-SETs.<ref>{{cite web|url=https://apps.db.ripe.net/docs/04.RPSL-Object-Types/02-Descriptions-of-Primary-Objects.html#description-of-the-as-set-object|title=Descriptions of Primary Objects - RIPE Database Docs|access-date=2023-04-05}}</ref>

AS-SETs are often used to simplify management of published routing policies. A routing policy is published in the IRR using "import" and "export" (or the newer "mp-import" and "mp-export") attributes, which each contain the source or destination AS number and the AS number imported or exported. Instead of single AS numbers, AS-SETs can be referenced in these attributes, which simplifies management of complex routing policies.