No, IRR assignments are only regional in terms of the company requesting them. A European company can use their RIPE resources anywhere in the world without "de

No, IRR assignments are only regional in terms of the company requesting them. A European company can use their RIPE resources anywhere in the world without "delegating" them. Yes, filter lists generated by recursively resolving IRR AS-SETs and RPKI can prevent incidents like this, if they were universally applied. Note that origin validation on its own (i.e. what RPKI does) does not prevent malicious attacks, which can just spoof the right origin. Some Tier 1's - most notably NTT - also use a mechanism called "Peer Lock", where an ASN can specify that it will only ever use a given set of transit providers (i.e. "NTT should never receive a Google prefix from a China Telecom peer"), which would have prevented this. https://archive.nanog.org/sites/default/files/Snijders_Everyday_Practical_Bgp.pdf https://archive.nanog.org/sites/default/files/Snijders_Every... https://blogs.akamai.com/Minimizing%20BGP%20Hijacking%20Risk_2018-10-29.pdf https://blogs.akamai.com/Minimizing%20BGP%20Hijacking%20Risk...