HP StorageWorks Fabric Interoperability: Merging Fabrics Based on M-series and B-series Fibre Channel Switches Application Notes (AA-RUQQL-TE, November 2009)

M-series features supported by Fabric OS 6.x
Fabric OS 6.x supports the M-series features described in this section. These features have some
limitations.
Domain ID offset configuration with Fabric OS 6.3.0 or later
This feature applies when you add B-series switches to an existing M-series fabric. This feature allows
different fabrics to have different domain ranges and expands the range of domains that B-series
switches support in interopmode 2 and interopmode 3. However, the maximum number of switches
in a fabric remains at 31.
Note the following:
• Domain ID offset configuration is used by M-series switches when assigning the first byte of the
PID for attached end devices. Homogeneous/McDATA Fabric mode supports a domain ID range
of 1–31 and McDATA Open Fabric mode supports a domain ID range of 97–127. The starting
offset of this range of domain IDs can be modified by adding an offset value (any multiple of 0x20
through 0xC0) to the actual domain ID of the switch and is used in assigning the PID. Traditionally,
M-series switches use an offset of 96. For example, a switch with a domain ID of 3 would assign
a value of 99 to the first byte of all PIDs and the domain ID range would be 97–127.
• Domain ID offset configuration changes affect the domain ID and all actions associated with this
change must also be made to the domain ID.
• You can implement this feature using the CLI, DCFM, WebTools, or any other user interface.
However, the domain ID offset must be consistent in all user interfaces.
Port Number Offset
Some M-series switch PIDs have an area field (the middle byte of the PID) with an offset of 4 added
to the port number. For example, physical port number 0 has an address value of 4 in the PID.
The port number offset is conveyed between the neighboring switches through the ESS ILS (exchange
security attributes), allowing neighboring switches to accurately identify port numbers and their
associated PIDs. The maximum port number is also available in the ESS ILS.
NPIV
NPIV management on a switch running FOS 6.x is the same as in the standard unmerged B-series
SAN.
Trunking
B-series switches support trunking when participating in an M-series fabric. Trunk ports (bandwidth
aggregation) only apply to ISLs between two B-series switches.
• Fabric OS frame-based trunking is supported for ISLs between B-series switches. Multiple ISLs
between a B-series switch and an M-series switch are allowed, but no frame-based trunking will
occur.
• Fabric OS exchange-level trunking (DPS) and source-port route balancing (DLS) are supported for
connections between B-series switches and M-series switches.
• M-series open trunking is supported for outbound ISLs from any M-series switch to any switch in
the fabric.
HP StorageWorks Fabric Interoperability: Merging Fabrics Based on M-series and B-series Fibre
Channel Switches Application Notes 9