Introduction 27Internal Network APowerVault NX3500's internal network A is comprised of two independentGigabit Ethernet ports. The internal network is the infrastructure for thePowerVault NX3500 clustering, and includes heartbeat monitoring, datatransfer, and mirroring of information between the controllers' caches. Theinternal network also distributes data evenly across all LUNs in the system.NOTE: Internal network A is also referred to as peer-to-peer connections. Thenetwork uses point-to-point cable connections.Internal Network BInternal network B is the PowerVault NX3500 internal management network,which is plugged into the SAN switch and connects both controllers. Alladministrative related functions are performed on this network.In the event where the controllers lose communication with each other butcontinue to function independently (known as the split-brain situation), thePowerVault management network automatically resets the suspectedcontroller. This prevents the split-brain situation and ensures data integrity.LAN or Client NetworkAfter the initial configuration, a virtual IP (VIP) address connects thePowerVault NX3500 to the client or LAN network.The VIP address allows clients to access the PowerVault NX3500 as a singleentity, thereby providing access to the file system. It enables the PowerVaultNX3500 to perform load balancing between controllers, and ensures that theservice continues even if a controller fails.The LAN or client network is comprised of two Gigabit Ethernet ports oneach controller, which connect to the LAN or client network switches. Thesolution can have a maximum of four VIPs that serve the system. For moreinformation, see “Setting Up Your PowerVault NX3500 Solution” on page 29.The PowerVault NX3500 solution is administered using the LAN or clientnetwork on the NAS Management VIP.
