May 31, 2015

vSphere Storage Terminologies - WWN

WWN

"All the objects (initiators, targets, and LUNs) on a Fibre Channel SAN are identified by a unique 64-bit identifier called a worldwide name (WWN). WWNs can be worldwide port names (a port on a switch) or node names (a port on an endpoint). For anyone unfamiliar with Fibre Channel, this concept is simple. It's the same technique as Media Access Control (MAC) addresses on Ethernet."

An example CNA has the following worldwide node name: worldwide port name (WWnN: WWpN) in the identifier column:
20:00:00:25:b5:10:00:2c 20:00:00:25:b5:a0:01:2f
"Like Ethernet MAC addresses, WWNs have a structure. The most significant two bytes are used by the vendor (the four hexadecimal characters starting on the left) and are unique to the vendor, so there is a pattern for QLogic or Emulex HBAs or array vendors. In the previous example, these are Cisco CNAs connected to an EMC VNX storage array."

WWNN

World Wide Node Name (WWNN), is a World Wide Name assigned to a node (an endpoint, a device) in a Fibre Channel fabric.

"With a single port HBA you have one WWN/WWNN (World Wide Node Name), and a single WWPN, and for multi-port cards you will still have a single WWN/WWNN"

Here is an example of single port HBA cards. Notice the WWNN, e.g. 20:00:00:00:C9:9F:0F:3A and the corresponding WWPN, 10:00:00:00:C9:9F:0F:3A


Here is an example of a dual port HBA card. Notice the single WWNN, e.g. 50:01:43:80:01:3B:DA:E0 and the two corresponding WWPNs, 50:01:43:80:01:3B:DA:E8 and 50:01:43:80:01:3B:DA:EC.

WWPN

A WWPN (world wide port name) is the unique identifier for a fibre channel port. It is a World Wide Name assigned to a port in a Fibre Channel fabric. It is functionally equivalent to the MAC address in Ethernet protocol.

In a single port HBA there is one WWNN and one WWPN.
For a dual port HBA, there is one WWNN and two WWPNs.

A WWN (world wide name) is a unique identifier for the node itself.

Here is an example of single port HBA cards.
Notice the WWNN, e.g. 20:00:00:00:C9:9F:0F:3A and the corresponding WWPN, 10:00:00:00:C9:9F:0F:3A

Here is an example of a dual port HBA card.
Notice the single WWNN, e.g. 50:01:43:80:01:3B:DA:E0 and the two corresponding WWPNs, 50:01:43:80:01:3B:DA:E8 and 50:01:43:80:01:3B:DA:EC

Reference:

No comments:

Post a Comment