NVIDIA Docs Hub NVIDIA Networking BlueField DPUs / SuperNICs & DOCA NVIDIA BlueField BMC Software v23.10 OOB Network 3-Port Switch Control

OOB Network 3-Port Switch Control

To enable both the BMC and the Arm on the DPU to access the out-of-band (OOB) network management interface, an L2, 3-port switch has been incorporated into the system. This switch acts as a bridge, connecting the RG45 port (OOB), the BMC, and the Arm in the DPU. It is important to note that the switch is exclusively managed by the DPU's BMC through a dedicated I2C line and a GPIO signal that controls the switch's reset function.

3-Port Switch IPMI Commands

netfunc	cmd	data	Description
0x32	0x97	N/A	Get 3-port switch ports mode. On success, it returns: 0x00 – all ports are allowed access to RJ45 0x01 – only BMC is allowed access to RJ45
0x32	0x98	0x00 – all ports are allowed access to RJ45 0x01 – only BMC is allowed access to RJ45	Set 3-port switch ports mode. Note: Setting this command is only possible while the user is logged on to the BMC, this command is not supported over the network interfaces (IPMI nor Redfish) Setting is persistent across power cycle and switch reset command
0x32	0xA1	0x3	Reset on-board 3-port switch

Note

In all these use cases, the internal pathway connecting the DPU and the BMC remains operational. This enables communication between the BMC and the DPU over the internal network.

Example for disabling the OOB network of the DPU Arm:

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            #bmc> ipmitool raw 0x32 0x98 0x1