Fibre Channel port numbers and worldwide port names

On IBM Spectrum Virtualize™ nodes, the Fibre Channel ports are identified by their physical port number and by a worldwide port name (WWPN).

The physical port numbers identify Fibre Channel (FC) adapters and cable connections when you run service tasks. The WWPN values uniquely identify the devices on the SAN and are required to complete tasks such as configuring Fibre Channel switches. The WWPN values are derived from the worldwide node name (WWNN) of the node in which the ports are installed.

WWNN format

The WWNN value for each IBM Spectrum Virtualize system has the following structure:

5005 0760 71NN NNNNh

For example, if the system contains three IBM Spectrum Virtualize nodes, the following WWNN values are established for each system:

5005 0760 7100 0000h: WWNN generated from the cluster ID of the first node
5005 0760 7100 0001h: WWNN generated from the cluster ID of the second node
5005 0760 7100 0002h: WWNN generated from the cluster ID of the third node

WWPN format

The WWNN value maps to the WWPN, which has the following format:

5005076071ppsssss

5: IEEE format
005076: Organizationally Unique Identifier (OUI) for IBM
071: Product Unique ID (PUI) for IBM Spectrum Virtualize
pp: Port identifier. In this port mask (see Table 1), the bottom 5-bits are used for the port ID, top 3-bits identify the different logical ports, 00 identifies the WWNN value of the node.
ssss: Serial number that was assigned when the node was manufactured.

Port identifier

The pp value in a WWPN relates to the port identifier or fc_io_port_id value shown in the output of the lsportfc command. As Table 1 shows, the port mask structure can support up to 31 ports with a 16-bit serial number. Primary and host ports are public, which means they are used in SAN zoning and in host and backend configuration. As such, these values must be preserved and must remain readily-identifiable when nodes are upgraded or added to the cluster.

Table 1. Summary of `fc_io_port_id` values
`fc_io_port_id`	`pp` values
`fc_io_port_id`	Primary	Host
1	01	81
2	02	82
3	03	83
...
15	0F	8F
16	10	90
17	11	91
...
30	1E	9E
31	1F	9F