Configuring Out-Of-Band Management Interface from In-Band Server

Most modern x86 servers include out-of-band Management or Lights-out Management systems. These systems offer remote configuration and remote console access to a headless server normally located in a datacenter. These are typically used when first setting up a server, or perhaps when the server is hosed. The company I work for is large enough to have dedicated server operators, and in my role I rarely if ever need to access the consoles of real devices. However, I recently needed to get to the console of a device and the server was in a different continent and timezone and I couldn't access the IP address I'd been emailed :( Not a good start to the day. I remember using ipmitool to configure OOB management before, but of course I never wrote down what I did then. As this blog is really a note taking memory aid system, I'm writing it down for next time. So using ipmitool I was able to determine the IP address of the server.

 1ipmiserver# ipmitool -I open lan print 1
 2Set in Progress         : Set Complete
 3Auth Type Support       : NONE MD2 MD5 PASSWORD
 4Auth Type Enable        : Callback :
 5                        : User     : MD2 MD5 PASSWORD
 6                        : Operator : MD2 MD5 PASSWORD
 7                        : Admin    : MD5
 8                        : OEM      :
 9IP Address Source       : Static Address
10IP Address              :
11Subnet Mask             :
12MAC Address             : 00:00:00:00:00:00
13SNMP Community String   : public
14IP Header               : TTL=0x40 Flags=0x40 Precedence=0x00 TOS=0x10
15BMC ARP Control         : ARP Responses Enabled, Gratuitous ARP Disabled
16Gratituous ARP Intrvl   : 2.0 seconds
17Default Gateway IP      :
18Default Gateway MAC     : 00:00:00:00:00:00
19Backup Gateway IP       :
20Backup Gateway MAC      : 00:00:00:00:00:00
21802.1q VLAN ID          : Disabled
22802.1q VLAN Priority    : 0
23RMCP+ Cipher Suites     : 0,1,2,3,4
24Cipher Suite Priv Max   : XaaaaXXXXXXXXXX
25                        :     X=Cipher Suite Unused
26                        :     c=CALLBACK
27                        :     u=USER
28                        :     o=OPERATOR
29                        :     a=ADMIN
30                        :     O=OEM

From this I noticed that the default gateway for the out-of-band was incorrect (as with all blog posts, the IPs are changed to RFC1918 private addresses here). What must have happen is that the server installation engineer had used a screen and keyboard on a trolley to configure the server, and then probably tested it from a device on the same subnet (I'm being generous here, as he/she may have never bothered testing it!) Anyway, quick man ipmitool for syntax and this was easily fixed from the in-band server with the following command:

1ipmitool -I open lan set 1 defgw ipaddr