Users Guide

12
Using FlexAddress and FlexAdress Plus Cards
This section provides information about FlexAddress and FlexAddress Plus cards, how to configure and use these cards.
Related links
About Flexaddress
About FlexAddress Plus
FlexAddress and FlexAddress Plus Comparison
About Flexaddress
If a server is replaced, the FlexAddress for the slot remains the same for the given server slot. If the server is inserted in a new slot
or chassis, the server-assigned WWN/MAC is used unless that chassis has the FlexAddress feature enabled for the new slot. If you
remove the server, it reverts to the server-assigned address. You need not reconfigure deployment frameworks, DHCP servers, and
routers for various fabrics for identifying the new server.
Every server module is assigned unique WWN and/or MAC IDs as part of the manufacturing process. Before FlexAddress, if you had
to replace one server module with another, the WWN/MAC IDs changes and Ethernet network management tools and SAN
resources had to be reconfigured to identify the new server module.
FlexAddress allows CMC to assign WWN/MAC IDs to a particular slot and override the factory IDs. Hence, if the server module is
replaced, the slot-based WWN/MAC IDs remain the same. This feature eliminates the need to reconfigure Ethernet network
management tools and SAN resources for a new server module.
Additionally, the override action only occurs when a server module is inserted in a FlexAddress enabled chassis; no permanent
changes are made to the server module. If a server module is moved to a chassis that does not support FlexAddress, the factory-
assigned WWN/MAC IDs is used.
The FlexAddress feature card contains a range of MAC addresses. Before installing FlexAddress, you can determine the range of
MAC addresses contained on a FlexAddress feature card by inserting the SD card into an USB Memory Card Reader and viewing
the pwwn_mac.xml file. This clear text XML file on the SD card contains an XML tag mac_start that is the first starting hex MAC
address that is used for this unique MAC address range. The mac_count tag is the total number of MAC addresses that the SD
card allocates. The total MAC range allocated can be determined by:
<mac_start> + 0xCF (208 - 1) = mac_end
where 208 is the mac_count and the formula is:
<mac_start> + <mac_count> - 1 = <mac_end>
For example:
(starting_mac)00188BFFDCFA + (mac_count)0xCF - 1 = (ending_mac)00188BFFDDC8
NOTE: Lock the SD card prior to inserting in the USB Memory Card Reader to prevent accidently modifying any of the
contents. You must unlock the SD card before inserting into CMC.
About FlexAddress Plus
The FlexAddress Plus is a new feature added to the feature card version 2.0. It is an upgrade from FlexAddress feature card version
1.0. FlexAddress Plus contains more MAC addresses than the FlexAddress feature. Both features allow the chassis to assign World
Wide Name/Media Access Control (WWN/MAC) addresses to Fibre Channel and Ethernet devices. Chassis assigned WWN/MAC
addresses are globally unique and specific to a server slot.
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