Is IPv6 supported over Site-to-Site VPN?
Yes. IPv6 is supported.
Can packets from the VCN be sourced with the public IP of the DRG? In other words, can the DRG source the NAT VCN traffic?
No. Packets from the VCN have the private IP address of the instance as a source IP address. Oracle cannot change the source IP address to the private or public IP address of the DRG.
Oracle has provided two VPN endpoints to build tunnels to. Does Oracle route the same network over both tunnels?
Yes. Traffic for all the subnets in the VCN attached to your DRG is routed over both tunnels.