ORA-27504: IPC error creating OSD context, ORA-27302: failure occurred at: skgxpcini3

CRS-5017: The resource action "ora.mydb.db start" encountered the following error:
ORA-27504: IPC error creating OSD context
ORA-27300: OS system dependent operation:check if failed with status: 0
ORA-27301: OS failure message: Error 0
ORA-27302: failure occurred at: skgxpcini3
ORA-27303: additional information: requested interface vnet5:1 interface not up
 _disable_interface_checking = TRUE to disable this check for single instance cluster. 
Check output from ifconfig co

Alert log error for instance:

SKGXP: ospid 10823: network interface with IP address 169.254.20.147 is DOWN

The error message mentions network interface vnet5:1 In this case vnet5 and vnet6 are private interconnects using HAIP hence the 169.254.x.x address (Link Local Address). On SERVER01, vnet5 is UP, no 169. address bound to it:

vnet5: flags=1000843 mtu 9000 index 6
        inet 10.0.84.194 netmask fffffff0 broadcast 10.0.84.207

On SERVER02, vnet5 not UP, has 169.254.20.147 bound to both vnet5 and vnet6!

vnet5: flags=1000842 mtu 9000 index 8
        inet 10.0.84.195 netmask fffffff0 broadcast 10.0.84.207
vnet5:1: flags=1000842 mtu 9000 index 8
        inet 169.254.20.147 netmask ffff8000 broadcast 169.254.127.255
vnet6: flags=1000843 mtu 9000 index 7
        inet 10.0.84.211 netmask fffffff0 broadcast 10.0.84.223
vnet6:1: flags=1000843 mtu 9000 index 7
        inet 169.254.164.136 netmask ffff8000 broadcast 169.254.255.255
vnet6:2: flags=1000843 mtu 9000 index 7
        inet 169.254.20.147 netmask ffff8000 broadcast 169.254.127.255

Fix was to reboot SERVER02 as it turned out the UNIX administrator had performed some work on the blades concerning MAC addresses for vnet5. Somewhere vnet5 and vnet6 got the link-local address mixed up.