What is Plogi and Flogi?

Port Login (PLOGI) After each device finishes the FLOGI phase, they now each have their own FCID. But they don’t know how to reach other devices connected to the same switch or connected to other switches in the fabric. In order to communicate with other devices, each device will need to do PLOGI.

What is PRLI?

Process Login (PRLI): This process is also performed between an N_port and another N_port. This login relates to the Upper Layer Protocols (Layer 4) in the Fibre Channel stack. An example would be SCSI. In this login type, the devices exchange SCSI-3 related service parameters.

What is WWPN storage?

A WWPN is a World Wide Port Name; a unique identifier for each Fibre Channel port presented to a Storage Area Network (SAN). Each port on an IBM Storage Device has a unique and persistent WWPN.

What is buffer credit in Brocade?

Brocade Switching Device. The number of available buffer credits defines the maximum amount of data that can be transmitted prior to an acknowledgment from the receiver. Buffer credits are physical memory resources that are incorporated in the Application-Specific Integrated Circuit (ASIC) that manages the port.

What is Fcid in Fibre Channel?

The FCID is similar to an IP address in Ethernet. It’s used by Fibre Channel switches to route traffic between servers and their storage. Switches maintain a table of FCID to WWPN address mappings and what port the host is located on. The Fibre Channel switches share information with each other.

What is WWPN & WWNN?

A WWPN is a World Wide Port Name; a unique identifier for each Fibre Channel port presented to a Storage Area Network (SAN). Each port on a Storage Device has a unique and persistent WWPN. A World Wide Node Name, WWNN, or WWnN, is a World Wide Name assigned to a node (an endpoint, a device) in a Fibre Channel fabric.

What is port WWN and Node WWN?

For a HBA mounted in a server the node WWN is the WWN of the HBA itself, the port WWN is the WWN of a specific port on this HBA.

What is difference between iSCSI and FC?

Because the iSCSI SAN is based on the well-known TCP/IP and Ethernet, it’s far simpler and less complex than FC. The learning curve and expertise requirement for FC is measurably higher. FC tends to be significantly more manually intensive vs. iSCSI, which has a lot more built-in automation.

What is the purpose of WWN in FC SAN?

A World Wide Name (WWN) is a unique identifier that is hard-coded into each Fibre Channel (FC) device by the device’s manufacturer. WWNs provide a method for identifying FC devices across the network.

What is slow drain in san?

Slow drain is a typical type of SAN congestion, mostly caused by misbehaving end devices. Further sections go into the details of slow drain. Information is provided to detect, troubleshoot, and automatically recover from the situation. Inter-Switch Link (ISL) build the core of a network.

What is R_rdy?

Upon receipt of a data frame, the receiver sends a status frame (R_RDY) to the transmitter indicating that the data frame was received and the buffer is ready to receive another data frame.

What is Cisco Flogi?

In short, flogi gives you the per switch information; which end devices have done a flogi on that particular switch / vsan. fcns gives you the same information for the fabric / vsan. Therefore you see the FC-ID which each switch of the fabric has (per vsan).

How do I calculate Fcid?

Get the FCID for the switch and then find the entry for this FCID in the “show fcns database detail”, this will give you the switch information.

What is WWPN and WWNN?

What is LUN masking in storage?

LUN masking is an authorization mechanism used in storage area networks (SANs) to make LUNs available to some hosts but unavailable to other hosts.