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## 2.5.2 Service IP address considerations 

Ethernet port 1 on each node canister is used for system management and, when required, for service access. In normal operation, the service IP addresses are not needed. However, if a node canister problem occurs, it might be necessary for service personnel to log on to the node to perform service actions. 

Figure 2-11 shows a logical view of the Ethernet ports that are available for the configuration of the service IP addresses. Only port one on each node can be configured with a service IP address. 

<img src='content_image/973479.jpg'>

## 2.6 Host configuration planning 

## 2.6.1 Fibre Channel connection 

In this section, we describe host configuration planning. 

Configuring your SAN with at least two independent switches, or networks of switches, ensures a redundant fabric with no single point of failure. If one of the two SAN fabrics fails, the configuration is in a degraded mode, but is still valid. Maintain separate fabrics for FCoE and FC. If you attempt to combine these fabrics, you might risk adding paths to the volumes. Supported configurations allow a maximum of eight paths. A SAN with only one fabric is a valid configuration, but risks loss of access to data if the fabric fails. SANs with only one fabric are exposed to a single point of failure. 

## 2.6.2 iSCSI configuration 

iSCSI hosts connect to the system through the node-port IP addresses, which can be assigned to any Ethernet port of the node. If the node fails, the address becomes unavailable and the host loses communication with the system via that node. To allow hosts to maintain access to data, the node-port IP addresses for the failed node are transferred to the partner node in the I/O group. The partner node handles requests for its own node-port IP addresses and also for node-port IP addresses on the failed node. This process is known as node-port IP failover . 

In addition to node-port IP addresses, the iSCSI name and iSCSI alias for the failed node are transferred to the partner node. After the failed node recovers, the node-port IP address and the iSCSI name and alias are returned to the original node. 

