HP Integrity BL870c i2 Server-Blade - Manual (Page 102)

Configuring the Virtual Connect domain using the CLI 102
IMPORTANT: Configuring Virtual Connect to assign server blade MAC addresses requires
careful planning to ensure that the configured range of MAC addresses is used once within
the environment. Duplicate MAC addresses on an Ethernet network can result in a server
network outage.
Each server blade Ethernet NIC ships with a factory default MAC address. The MAC address is a 48-bit
number that uniquely identifies the Ethernet interface to other devices on the network. While the hardware
ships with default MAC addresses, Virtual Connect has the ability to assign MAC addresses that will
override the factory default MAC addresses while the server remains in that Virtual Connect enclosure.
When configured to assign MAC addresses, Virtual Connect securely manages the MAC addresses by
accessing the physical NICs through the enclosure Onboard Administrator and the iLO interfaces on the
individual server blades.
Always establish control processes to ensure that a unique MAC address range is used in each Virtual
Connect domain in the environment. Reusing address ranges could result in server network outages
caused by multiple servers having the same MAC addresses.
If using Virtual Connect assigned MAC addresses, the following notes apply:
• Virtual Connect automatically reserves both a primary address and an iSCSI MAC address for use
by multifunction gigabit server adapters, such as the HP NC373m PCI Express Dual Port
Multifunction Gigabit server adapter. Only the primary MAC address is used by standard (not
multifunction) Ethernet devices.
• If a server blade is moved from a Virtual Connect managed enclosure to a non-Virtual Connect
enclosure, the local MAC addresses on that server blade are automatically returned to the original
factory defaults.
• If a server blade is removed from a bay within a Virtual Connect domain and installed in another
bay in the same Virtual Connect domain or in a bay in a different domain, it is assigned the new set
of addresses appropriate for that server location.
Assigned MAC addresses
The MAC address range used by the Virtual connect domain must be unique within the environment. HP
provides a set of pre-defined ranges that are for use by Virtual Connect Manager and will not conflict
with server factory default MAC addresses.
When using the HP-defined MAC address ranges, ensure that each range is used only once within the
environment.
Selecting VC-assigned MAC address ranges
When using VC-assigned MAC addresses, you can choose between using an HP pre-defined MAC
address range or using a user-defined MAC address range.
• HP pre-defined MAC address range (recommended). These pre-defined ranges are reserved and
appear as factory default on any hardware. There are 64 ranges of 1024 unique addresses to
choose from. Be sure to use each range only once within a data center.
• User-defined MAC address range. To avoid potential conflict with other hardware MAC addresses
in the environment, consider using a subrange of MAC addresses reserved by the IEEE for locally-
administered MAC addresses. Ensure that the range does not conflict with any Ethernet device
already deployed within the enterprise.