LAN transport mode includes two type: NBD and NBDSSL. The Network Block Device (NBD) protocol uses storage on a remote host as a block device; NBDSSL uses SSL to encrypt all data transmitted over TCP connections, providing higher security. In LAN transport mode, the third-party backup app accesses the disk data of business VMs through the backup data transfer network.

During agentless backup:

1.Start the NBD service on the HCI host, and mount the disk snapshot of the business VM (for backup scenarios) or directly mount the disk (for recovery scenarios).

2.The third-party backup app calls SFVDDK, and SFVDDK requests the NBD service via the backup data transfer network using the NBD protocol to access the business VM disk.

Figure 1-3 NBD and NBDSSL Transport Modes