36 Fabric OS Administrator’s Guide
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PIDs and PID binding overview
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Core PID addressing mode

Core PID is the default PID format for Brocade platforms. It uses the entire 24-bit address space of
the domain, area_ID, and AL_PA to determine an objects address within the fabric.
The Core PID is a 24-bit address built from the following three 8-bit fields:
•domain, written in hex and the numeric range is from 01-ee (1-239)
•area_ID, written in hex and the numeric range is from 01-ff (1-255)
•AL_PA
For example, if a device is assigned an address of 0f1e00, the following would apply:
•0f is the domain ID.
•1e is the area ID.
•00 is the assigned AL_PA.
From this information, you can determine which switch the device resides on from the domain ID,
which port the device is attached to from the area_ID, and if this device is part of a loop from the
AL_PA number.
For more information on reading and converting hexadecimal, refer to Appendix E, “Hexadecimal”.

Fixed addressing mode

Fixed addressing mode is the default addressing mode used in all platforms that do not have
Virtual Fabrics enabled. When Virtual Fabrics is enabled on the Brocade DCX and DCX-4S, fixed
addressing mode is used only on the default partition. With fixed addressing mode enabled, each
port has a fixed address assigned by the system based on the port number. This address does not
change unless you choose to swap the address using the portSwap command.

10-bit addressing mode

This is the default mode for all the logical switches created in the Brocade DCX and DCX-4S
enterprise-class platforms. This addressing scheme is flexible to support a large number of
F_Ports. In the regular 10-bit addressing mode, the portAddress --auto command supports
addresses from 0x00 to 0x8F.
NOTE
The default switch in the Brocade DCX and DCX-4S enterprise-class platform still uses the fixed
addressing mode in order to support 4 Gbps blades.
The 10-bit addressing mode utilizes the 8-bit area_ID and the borrowed upper two bits from the
AL_PA portion of the PID. Areas 0x00 through 0x8F use only 8 bits for the port address and support
up to 256 NPIV devices. This means a logical switch can support up to 144 ports that can each
support 256 devices. Areas 0x90 through 0xFF use an additional two bits from ALPA for the port
address. Hence these ports support only 64 NPIV devices per port.
10-bit addressing mode allows for the following functionalities:
•PID is dynamically allocated only when the port is first moved to a logical switch and thereafter
it is persistently maintained.
•Shared area limitations are removed on 48-port blades.