Can't find IPMI mac address

Question

The MAC address listed under ipmitool lan print seems to be incorrect, since there is no entry in the arp cache for the set ip address, 10.224.242.121:

# arp 10.224.242.121 10.224.242.121 (10.224.242.121) -- no entry

Obviously the ipmi interface cannot establish layer 2 connectivty because of this. After a good amount of googling, I can't figure out how to find the correct IPMI mac address....

I am running centos6.5 on a supermicro server. Any help would be greatly appreciated.

Solution

I find it very strange that the MAC reported by ipmitool is not correct. To double check, you can do the following:

Set the BMC ipsrc to static with IP 0.0.0.0

ipmitool lan set 1 ipsrc static
ipmitool lan set 1 ipaddr 0.0.0.0

Fire up a packet analyzer on your machine connected to the same subnetwork (e.g. Wireshark, tcpdump).

Set the BMC ipsrc to dhcp, this will trigger a DHCP discover.

ipmitool lan set 1 ipsrc dhcp

Verify with the packet analyzer the source MAC address of the DHCP discover packet broadcasted on the network by the BMC.

Comments

[joeqwerty]

Does the computer you're looking at the ARP cache on have an ip address in the same subnet as the IPMI? If not then there wouldn't be an ARP entry for the IPMI.

[lobi]

Yes, it does...

[Brian]

Keep in mind the ARP cache timeout is often just 60 seconds. So if there has been no recent traffic to that IP address there would be no entry in the ARP cache.