Worldwide node and port names

A worldwide name is a unique name that is composed of 16 hexadecimal digits that are allocated to a node, service, or port on the SAN. A worldwide name that is allocated to a node is called a worldwide node name (WWNN). A worldwide name that is allocated to a port or other SAN service is referred to as a worldwide port name (WWPN).

Each node canister in a control enclosure is allocated a WWNN. The WWNN is used as the basis for the unique WWPN that is assigned to each Fibre Channel port or service on the node canister. The WWNN for each node canister is stored within the enclosure. When you replace a node canister, the WWPN of the ports and services in the enclosure do not change. You must know the WWNN and WWPN values when you configure the SAN. These names are also useful if you need to troubleshoot SAN and system connectivity issues.

The WWNN has the following format, where xxxx is a unique number that was assigned when the enclosure was manufactured:

500507681000xxxx

The WWPNs are derived from the WWNN of the node canister in which the ports are installed. The WWPNs are also derived from the PCIe slot and the port ID on the adapter. When N-Port ID Virtualization (NPIV) is enabled, each WWPN also has an NPIV WWPN value that should be used for communications with hosts. Table 1 summarizes the different WWPN values per port.

Table 1. WWPN values per port
PCIe slot	Adapter port ID	Physical WWPN	NPIV WWPN for hosts
1	1	500507681011xxxx	500507681015xxxx
	2	500507681012xxxx	500507681016xxxx
	3	500507681013xxxx	500507681017xxxx
	4	500507681014xxxx	500507681018xxxx
2	1	500507681021xxxx	500507681025xxxx
	2	500507681022xxxx	500507681026xxxx
	3	500507681023xxxx	500507681027xxxx
	4	500507681024xxxx	500507681028xxxx

When a host is cabled directly to a Fibre Channel port of a node canister, other similarly formatted WWPNs are exposed by the Fibre Channel services that are necessary for direct attachment.