If you want to advertise prefixes from another network (ASN) to your embedded OCA(s), you should first ensure that you have created an AS-SET in your internet routing registry (IRR) record that includes the ASN(s) that are associated with those prefixes. This documentation allows us to attribute ASN ownership of prefixes that you advertise to Netflix.
Note: When you set up your AS-SET record, refer to the "aut-num" object (routing record) that describes the routing policies for your ASN. The AS-SET record must have the same "mnt-by" handler (also known in some internet registries as the "admin-c") as the "aut-num" so that our systems can recognize and associate them.
What is the benefit of using an AS-SET?
AS-SETs provide a mechanism for publicly documenting a customer relationship between autonomous systems (ASNs). By creating an AS-SET with a members attribute that includes each network (ASN) with which you have an established relationship (transit, peering, and so on), you can formally document the networks that are authorized and expected to be served from your OCA(s). As a result, Netflix will receive an unambiguous signal that all prefixes associated with the ASNs in your AS-SET are fully authorized and expected.
For more information on the importance and benefits of using AS-SETs, see this article: https://www.manrs.org/2022/12/why-network-operators-should-use-hierarchical-as-sets/
How can I verify that my AS-SET is set up correctly?
To verify that your AS-SET is correctly defined, you can run a query via RADb.
What if I have a downstream customer, and they also have downstream customers?
In this case, you should add a reference to your downstream customer's AS-SET in your AS-SET. Their AS-SET should in turn list all of the downstream ASNs that they have a relationship with.
Isn't my peeringDB record sufficient to document my network relationships? Do I really need to create an AS-SET?
PeeringDB stores information about peering relationships, and we do use peeringDB as a source to determine ASN ownership of prefixes. However, it is not sufficient as a single data source. We use registered AS-SET hierarchies to verify relationships between ASNs.
More information
For more information about AS-SETs, see these additional resources:
https://learn.nsrc.org/bgp/irr_objects
https://www.apnic.net/manage-ip/using-whois/guide/as-set/