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Although two ports on each system are configured for remote copy port group 1, only one Ethernet port in each system actively participates in the IP partnership process. This selection is determined by a path configuration algorithm that is designed to choose data paths between the two systems to optimize performance. 

The other port on the partner node in the I/O Group behaves as a standby port that is used if a node fails. If Node A1 fails in System A, IP partnership continues servicing replication I/O from Ethernet Port 2 because a failover port is configured on Node A2 on Ethernet Port 2. 

However, it might take some time for discovery and path configuration logic to reestablish paths post failover. This delay can cause partnerships to change to Not_Present  for that time. The details of the particular IP port that is actively participating in IP partnership is provided in the lsportip  output (reported as used ). 

This configuration has the following characteristics: 

– Each node in the I/O group has the same remote copy port group that is configured. However, only one port in that remote copy port group is active at any time at each system. 

– If the Node A1 in System A or the Node B2 in System B fails in the respective systems, IP partnerships rediscovery is triggered and continues servicing the I/O from the failover port. 

– The discovery mechanism that is triggered because of failover might introduce a delay where the partnerships momentarily change to the Not_Present  state and recover. 

GLYPH<SM590000> Two 4-node systems in IP partnership over a single inter-site link (with failover ports configured), as shown in Figure 11-100 (configuration 3). 

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