Supermicro motherboards often implement IPMI through one of these methods:

1. Dedicated physical NIC (usually labeled IPMI/BMC)
2. Shared NIC (piggybacking on one of the server's existing network interfaces)
3. Virtual LAN (VLAN) configuration

For the H8DMR-I2 model specifically, the IPMI shares physical layer connectivity with the primary NIC (eth0 by default).

Use these commands to identify the shared interface:

# Check current IPMI channel configuration
ipmitool lan print 1

# Verify active interfaces
ip a

Look for these key indicators:

• Channel 1 is typically the shared LAN channel
• "Shared" flag in ipmitool output
• MAC address correlation between IPMI and physical NIC

To configure IPMI to use eth0's network:

# Set IP address (replace with your network settings)
ipmitool lan set 1 ipsrc static
ipmitool lan set 1 ipaddr 192.168.1.100
ipmitool lan set 1 netmask 255.255.255.0
ipmitool lan set 1 defgw ipaddr 192.168.1.1

# Enable shared functionality
ipmitool raw 0x30 0x70 0x0c 0 1

From a remote machine:

ping 192.168.1.100
ipmitool -H 192.168.1.100 -U ADMIN -P ADMIN chassis status

Important notes:

• Shared NIC IPMI typically cannot be accessed from the host itself
• Traffic must come through the switch (not localhost)
• VLAN tagging might be required in some environments

If IPMI remains unreachable:

1. Verify physical network connection on the correct port
2. Check switch port configuration (VLANs, spanning-tree)
3. Confirm IPMI firmware version compatibility
4. Test with direct crossover cable connection

To check firmware version:

ipmitool mc info | grep "Firmware Revision"

For environments requiring VLAN separation:

# Set VLAN ID (example uses VLAN 10)
ipmitool lan set 1 vlan id 10
ipmitool lan set 1 vlan priority 0

# Persist configuration
ipmitool mc reset cold

Remember that shared NIC implementations vary by motherboard generation. Always consult your specific board's manual for exact implementation details.

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The Supermicro H8DMR-I2 motherboard implements IPMI 2.0 through a "shared LAN" configuration rather than dedicated BMC port. In this setup, the Baseboard Management Controller (BMC) shares one of the physical NICs (eth0 or eth1) through NC-SI (Network Controller Sideband Interface) technology.

First, check which NIC is currently hosting the IPMI interface:

# ipmitool lan print 1 | grep -i "shared"
# ipmitool raw 0x30 0x70 0x0c 0x00

For Ubuntu 10.04, examine the kernel messages:

# dmesg | grep -i ncsi
# grep -r ncsi /sys/class/net/eth*/device/

The shared NIC must be:

• Configured with promiscuous mode enabled
• On the same VLAN as the IPMI traffic
• Using a different IP subnet than the host OS

Example configuration for eth0:

# ifconfig eth0 promisc
# ipmitool lan set 1 ipsrc static
# ipmitool lan set 1 ipaddr 192.168.1.100
# ipmitool lan set 1 netmask 255.255.255.0
# ipmitool lan set 1 defgw ipaddr 192.168.1.1

Common issues and solutions:

1. No Link Light: Check physical connection and try the other NIC
2. ARP Resolution: Verify IPMI MAC address is visible:

   # ipmitool lan print 1 | grep "MAC Address"
   # arp -a | grep [IPMI_MAC]

3. Firewall Rules: Temporarily disable firewall:

   # iptables -F
   # ip6tables -F

For deeper investigation:

# ipmitool mc info
# ipmitool channel info
# ipmitool bmc reset cold
# ethtool -i eth0 | grep bus-info
# lspci -vvv -s [BDF] | grep -i ncsi

When direct network access isn't working:

• Use serial-over-LAN (SOL) via ipmitool:

  # ipmitool -I lanplus -H [IP] -U [USER] -P [PASS] sol activate

• Access via host OS using local interface:

  # ipmitool -I open chassis status