McDATA StorageWorks 2/140 - Director Switch Planning Manual page 126

Planning Considerations for Fibre Channel Topologies
3
Port Numbering Versus
Port Addressing
McDATA Products in a SAN Environment - Planning Manual
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• When a director or fabric switch is set to open systems
management style, FCP connectivity is defined within a Fibre
Channel fabric using WWNs of devices that are allowed to form
connections. When connecting to the fabric, an FCP device
queries the name server for a list of devices to which connectivity
is allowed. This connectivity is hardware-enforced through a
name server zoning feature that partitions attached devices into
restricted-access zones.
• When a director or fabric switch is set to FICON management
style, host-to-storage FICON connectivity and channel paths are
defined by a host-based hardware configuration definition (HCD)
program and a director or switch-resident management server
called the control unit port (CUP). A user-configured (director or
switch-resident) prohibit dynamic connectivity mask (PDCM)
array associates logical port addresses. FICON devices do not
query the name server for accessible devices because connectivity
is defined at the host, and additionally at the director or switch.
This connectivity is hardware-enforced in the routing tables of
each port.
NOTE: The Intrepid 10000 Director and Sphereon 4300, 4400, and 4500
Fabric Switches do not support operation using FICON management
style nor transmission of FICON frames.
PDCM connectivity control is configured and managed at the
director or switch level using the Configure Allow/Prohibit Matrix -
Active dialog box (Figure
PDCM Arrays.
ATTENTION ! When configuring a PDCM array that prohibits E_Port
connectivity, mistakes can render ISLs unusable and cause complex routing
problems. These problems can be difficult to fault isolate and sometimes
manifest incorrectly as end-device issues.
Consideration must be given to the implications of port numbering
for the FCP protocol versus logical port addressing for the FICON
protocol. FCP configuration attributes are implemented through
zoning. Zones are configured through the associated Element
Manager application by:
• The eight-byte (64-digit) WWN assigned to the host bus adapter
(HBA) or Fibre Channel interface installed in a device connected
to the director or switch.
5-4). For additional information, refer to