On 11/18/19 8:30 PM, Nathan Beard wrote:

Google peering sessions via MICE have been down for nearly 8 hours at this point for multiple customers including Stellar Association. For networks that have Google caches, are you advertising only customer routes to them, or also advertising peer routes? The latter supposedly enables peer-to-peer cache fill, which may be helpful, especially in times like this.

https://support.google.com/interconnect/answer/7658603

What should I advertise to the GGC node? You should advertise all your user prefixes. If you have peers and downstream customers, you may advertise their prefixes too.

https://support.google.com/interconnect/answer/7658593

Can GGC nodes cache-fill from other GGC nodes? Yes. We refer to this as peer-to-peer cache-fill. It can lead to substantial improvements in resilience, and reduction in transit or AS15169 peering traffic.

To enable peer-to-peer traffic, the IP prefix of the GGC servers must be advertised to all GGC nodes that you want to be candidates to be cache-fill sources. These other nodes can be in your network or nodes hosted by your peers.

It is possible for cache-fill traffic to flow in both directions between two nodes, or between two ASNs.

-- Richard