external_addr is good news. I think this will resolve the peering issues for GCP/AWS nodes, and solve the problem some of us had with validators losing connectivity.
I wonder if will cause an inverse problem in a sentry node topology that will likely be common. GCP, AWS and other complex cloud providers provision private IPs in virtual private cloud networks, and allow public IPs to be mapped to the private IP. Bare metal validators in co-location facilities connected to sentries in GCP/AWS using VPN connectivity will likely be a common topology for resilient validators. In this topology, the sentry will be peering with outside nodes via it’s public IP, and with the validator via it’s private IP. I haven’t thought through the network routing issue in depth, this may be easy to solve with static routes in the VPN, and I don’t know enough about the P2P layer to to know if it’s even possible for one instance of gaiad to peer using different IP addresses.
Anyone have thoughts about this? There hasn’t been much discussion about the topologies that validators will build. I assume that VPN from co-lo to cloud, private peering relationships between operators using VPC peering, and eventually SDN or private links between sites will be used to develop the resiliency that we want to build.