Dell PowerVault 51F (8P Fibre Channel Switch) - Manual (Page 48)

2-2 Dell PowerVault 51F 8-Port Fibre Channel Switch Installation and Troubleshooting Guide
DELL CONFIDENTIAL - Preliminary 4/6/00
FILE LOCATION: S:\SYSTEMS\Boxer\rev_i&t\English\50UWDa00\50UWDc20.fm
Cascading and Configuring Switches
When configuring switches in a fabric, optimize the fabric performance based on the
most significant expected use.
NOTES: Except for unique identifiers such as the switch name, domain name, and IP
address, all switches in a fabric must have the same firmware configuration. Switches
that are configured differently are isolated from the fabric.
Live switches may be cascaded; however, the domain IDs must be different. If the
domain IDs of any of the switches are identical, the fabric will segment and a fabric
segment error will be reported. This problem can be resolved by rebooting one of the
switches with a conflicting domain ID.
The PowerVault 51F switch runs on version 2.0 of the software only. To be compatible
with PowerVault 50F software, the PowerVault 51F system must be configured using
VC Encoded Address Mode, which limits the switch count in a fabric to 32 and the
number of multicast groups to 31. See Chapter 3, “Managing the PowerVault 51F
Switch Manager,” for more information.
Cascaded topologies using multiple switches give switching system designers a
powerful, flexible set of resources to create high-performance, robust storage area
networks (SAN), or data center backbone.
Universal Ports
All eight switch ports are universal supporting F, FL, and E-port modes of operation.
They are designed to automatically select the optimum mode.
Public Operation
In public operation, all loop devices are accessible to all other fabric-connected
devices and loop devices within the fabric. The loop devices behave the same as
devices attached directly to the fabric.
Private Operation
Dell’s FL_Port translative mode allows private devices on a local loop to communicate
with fabric-attached devices and vice versa. Fabric-attached devices can be either
N_Ports attached to G_Ports or public NL_Ports attached to other FL_Ports.
Logically, private and fabric-attached devices that communicate to a loop appear to be
devices on the same loop as the private devices. Each fabric-attached device uses an
unassigned AL_PA from the local loop. When private devices on a local loop and
fabric-attached devices communicate, the FL_Port automatically translates between
private and public addresses.
The FL_Port translative mode supports up to 32 fabric-attached devices (one is
reserved for the fabric) appearing on each local loop of private devices, subject to the
limit of 126 devices on a loop (the total of private and fabric-attached devices).
Private devices are registered to the Simple Name Server (SNS), so the
fabric-attached devices can query SNS for their addresses and initiate communication.