In the same way that if a compute instance fails, if a physical network node fails our monitoring systems will detect the failure and trigger the evacuate process that will ensure all affected virtual router instances are restarted on a healthy server. This process usually takes between 5 to 20 minutes.
Customers requiring high availability are advised to combine compute instances from multiple regions where possible.
By default your networks and instance cannot access or connect to one another across different regions. Regions are completely independent and isolated from each other, providing fault tolerance and geographic diversity. This ensures that if an instance or network were compromised by some disaster natural or otherwise; the instances in separate regions would not be affected. There are ways to go around this if you need to connect instances or networks across a region for some purpose. This can be done using Virtual private networks