Restricting ASRock Rack BMC to dedicated IPMI

I've written before about my media server's motherboard, the ASRockRack E3C246D4U. This week I've been performing some long overdue network upgrades which included implementing VLANs and automating DHCP / DNS.

However, during this process I came across a frustrating "bug" in the Asrock Rack BMC implementation. No matter the settings I gave the BMC it was getting two IP addresses. One on the IPMI_LAN port as expected in my management VLAN, and another on eth0 which is undesirable.

TL;DR - The Solution

The end result I was looking for a single IP on the 10.42.10.21 interface. This was the port on the switch tagged for the management VLAN. IP2 should not exist.

My answer ended up coming from a reddit thread. I needed to run:

ipmitool raw 0x32 0x71 0x00 0x01 0x00

I then rebooted the BMC with ipmitool -H 10.42.10.21 -U admin -P hunter2 mc reset cold and only the IPMI_LAN port grabbed an IP. Perfect.

Extra info - just in case

I've included a bit more information here just in case it helps you. I found the answer above worked immediately so perhaps try that first.

I attempted to disable BMC registration in the web interface for eth0 which did not prevent it grabbing an IP. I made sure to disable bonding.

I set a static IP like so.