Google compute engine private ASNs

Hey, first post so sorry if it's misguided. I'm curious about the BGP implementation in Google compute engine that allows you to define routing policy using private ASN numbers. How similar is it in terms of learning about BGP as a broader concept, or is it all smoke and mirrors? I'm not in a position where iBGP would benefit me in any other context than learning so I'm keen not to bother if it's too abstracted from a real world scenario. Lee Fuller (mobile) PGP Fingerprint: 4ACAEBA4B9EE1B3A075034302D5C3D050E6ED55A