text: Ethernet port 1 on every node must be connected to the same set of subnets. The same rule 
  applies to Ethernet port 2 if it is used. However, the subnets available for Ethernet port 1 do 
  not have to be the same as configured for interfaces on Ethernet port 2. 
  
  Each Storwize V7000 cluster has a Cluster Management IP address, in addition to a Service 
  IP address for each node in the cluster (see Example 3-1). 
  
  Example 3-1 System addressing example 
  
  management IP add. 10.11.12.120 
  node 1 service IP add. 10.11.12.121 
  node 2 service IP add. 10.11.12.122 
  
  Each node in an Storwize V7000 clustered system must have at least one Ethernet 
  connection. Both IPv4 and IPv6 addresses are supported. Storwize V7000 can operate with 
  either Internet Protocol or with both internet protocols concurrently. 
  
  For configuration and management, you must allocate an IP address to the system, which is 
  referred to as the management IP address. For more fault tolerance, you can also configure a 
  second IP address for the second Ethernet port on the node. The addresses must be fixed 
  addresses. If both IPv4 and IPv6 are operating concurrently, an address is required for each 
  protocol. 