Server Management Guide
Baseboard Management Controller
Intel
®
Server Boards and Server Platforms Server Management Guide 33
MAC addresses are assigned for management NICs from a pool of up to 3 MAC addresses allocated
specifically for manageability. The total number of MAC addresses in the pool is dependent on the
product HW constraints (for example, a board with 2 NIC ports available for manageability would have a
MAC allocation pool of 2 addresses).
IPMI-enabled network interfaces may not be placed on the same subnet. This includes the Intel
®
Dedicated Server Management NIC and either of the BMC’s embedded network interfaces.
Host-BMC communication over the same physical LAN connection – also known as “loopback” – is not
supported. This includes “ping” operations.
On baseboards with more than two onboard NIC ports, only the first two ports can be used as BMC LAN
channels. The remaining ports have no BMC connectivity.
Maximum bandwidth supported by BMC LAN channels are as follows:
BMC LAN1 (Baseboard NIC port) ----- 100M (10M in DC off state)
BMC LAN 2 (Baseboard NIC port) ----- 100M (10M in DC off state)
BMC LAN 3 (Dedicated NIC) ----- 1000M
In additional to IPv4, this generation of servers supports IPv6 for manageability channels.
2.6.3 Dedicated MAC Address
Each of the BMC’s two NIC channels has a unicast MAC filter reserved for BMC use. These filters
enable the BMC to receive network data streams that are logically separate from, and invisible to,
operating systems and software running on the server, despite sharing the same physical LAN
connections. This allows the BMC to support features beyond standard IPMI-over-LAN, such as
DHCP, full ARP request/response, and ICMP, without requiring a separate Ethernet cable.
If the platform has two NIC built into the main board then there will be five MAC addresses assigned
as follows:
NIC 1 MAC address (for OS usage)
NIC 2 MAC address = NIC 1 MAC address + 1 (for OS usage)
BMC LAN channel 1 MAC address = NIC1 MAC address + 2
BMC LAN channel 2 MAC address = NIC1 MAC address + 3
BMC LAN channel 3 (RMM) MAC address = NIC1 MAC address + 4
If the platform has four NIC built into the main board then there will be seven MAC addresses assigned
as follows:
NIC 1 MAC address (for OS usage)
NIC 2 MAC address = NIC 1 MAC address + 1 (for OS usage)
NIC 3 MAC address = NIC 1 MAC address + 2 (for OS usage)
NIC 4 MAC address = NIC 1 MAC address + 3 (for OS usage)
BMC LAN channel 1 MAC address = NIC1 MAC address + 4
BMC LAN channel 2 MAC address = NIC1 MAC address + 5