[AusNOG] Google's Route Preference

[Joseph Goldman]

Hi Team,

  After Megaport's hiccup yesterday, I discovered my Google traffic 
coming in via my transit rather than alternate peering fabric.

  We bi-lat peer with Google over Megaport IX, but not over other 
peering fabrics, but common sense told me that without bi-lat, it should 
still use the Route Server routes and come in via alternate peering, I 
was wrong!

  Google support confirmed the following preferences:

  "Google generally serves traffic from edge nodes (GGC) preferentially, 
then direct peering, then via indirect paths (your transit such as xxxx 
and xxxx), and Route servers to be the least preferred"

  Now, its their network and they can prefer what they want to prefer, 
what I am interested in though is maybe an understanding why?

  Why would route server routes be less preferred than transit?

  In any case my easy solution is to set up bi-lat via all peering 
fabrics, just caught me off guard and goes against what I would think is 
common sense routing.

Thanks,
Joe