Hi,
The problem is the same as in this thread: S3200sh ipmi configuration
I'm posting another discussion as that discussion is already 4 years old.
I encountered the same problem just recently with my Intel Server SR1530HS with the board above. Basically, I'm trying to use the IPMI interface as a fencing device for a 2-node CentOS cluster. I already followed Edward's recommendation to update the BIOS and firmwares to the latest available version. Did that earlier today yet still no luck on BMC LAN access.
Francis