BMC not responsive after OS Linux boot?

I'm in the process of testing a rebuilding an HPC, and I have a Dell PowerEdge R810 that I rebuilt, and upon boot of the OS, lose connectivity to BMC with ipmitool or web GUI.

The LOM in BMC is configured to shared.

Have tried disabling the ethernet links within Linux to no avail.

Any ideas as to what I can try next?

Thanks

Dan

[user@devhpc ~]$ ipmitool -I lanplus -H 172.16.100.34 -U ***** -P ***** delloem lan get
shared


[danc@devhpc ~]$ ipmitool -I lanplus -H 172.16.100.34 -U ***** -P ***** lan print
Set in Progress         : Set Complete
Auth Type Support       : NONE MD2 MD5 PASSWORD
Auth Type Enable        : Callback : MD2 MD5
                        : User     : MD2 MD5
                        : Operator : MD2 MD5
                        : Admin    : MD2 MD5
                        : OEM      :
IP Address Source       : Static Address
IP Address              : 172.16.100.34
Subnet Mask             : 255.255.0.0
MAC Address             : 14:fe:b5:ca:05:bd
SNMP Community String   : public
IP Header               : TTL=0x40 Flags=0x40 Precedence=0x00 TOS=0x10
Default Gateway IP      : 172.16.100.254
Default Gateway MAC     : 00:00:00:00:00:00
Backup Gateway IP       : 0.0.0.0
Backup Gateway MAC      : 00:00:00:00:00:00
802.1q VLAN ID          : Disabled
802.1q VLAN Priority    : 0
RMCP+ Cipher Suites     : 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14
Cipher Suite Priv Max   : aaaaaaaaaaaaaaa
                        :     X=Cipher Suite Unused
                        :     c=CALLBACK
                        :     u=USER
                        :     o=OPERATOR
                        :     a=ADMIN
                        :     O=OEM
Bad Password Threshold  : Not Available