Dell PowerVault 56F (16P Fibre Channel Switch) - Manual (Page 32)

2-2 Installation and Troubleshooting Guide
information regarding the cost of the shortest path to another switch from which you
can derive the number of hops. The cost should not exceed 7000 (7 x 1000).
A fabric using Dell switches in cascaded topologies should be configured to deliver
the required bandwidth and fault tolerance with all connections made within the
seven-hop maximum limit.
NOTE: The maximum number of hops supported in a Dell Storage Area Network
(SAN) configuration may be less than seven. This number is determined by the fea-
tures of the connected devices.
' '
#
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.
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 segments and a fabric seg-
ment error is reported. You can resolve this problem by rebooting one of the switches
with a conflicting domain ID.
To be compatible with the PowerVault 50F switch, the VC Encoded Address mode is
enabled by default on the PowerVault 56F switch. In the event that you need to
upgrade the firmware on your PowerVault 56F switch refer to the firmwareDown-
load command found later in this chapter.
7
All 16 switch ports are universal supporting F_, FL_, and E-port modes of operation.
They are designed to automatically select the optimum mode.
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.
Dell’s FL_Port translative mode allows private devices and fabric-attached devices on a
local loop to communicate with each other. 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