Geographically separated nodes in the same subnet are protected against the same double failures as collocated ones, but additionally is also guarded against some more double failures of the same kind at one data center without loss of service.
System Specific Information
Double router failure at one data center: The node loses connection, but is still connected to the partner node. The impact depends on whether the connection to the Admin network or the Signaling network or Billing network is restricted and result in the same as the respective single failure.Parent topic: Cluster Redundancy
Double LAN failure at one data center: The node is completely isolated from the network and the partner takes over with the help of the Survival Authority; the maintenance controller of the isolated node is not available.
Double bridge failure: An outage of the L2 bridge or one of the redundant network connections between two L2 bridges between the two data centers results in the loss of one of the cluster interconnect connections. All site-to-site LAN traffic uses the remaining LAN bridge.