Dell SmartFabric OS10 User Guide Release 10.5.4

PXE booting use case

The following topology depicts the use of the LACP individual feature in a PXE booting use case:

PXE booting occurs in the following sequence:

1. The SmartFabric OS10 switch and PXE client connect through a LACP port-channel. The port-channel can be a normal port-channel or a VLT-port-channel.
2. After starting up, the PXE client does not have LACP configurations and does not send LACP PDUs. As a result, ports in the SmartFabric OS10 switch connected to the PXE client become LACP individual ports.
3. The PXE client sends DHCP requests on all ports.
4. In the PXE client, a DHCP offer with an IP address and DHCP or PXE server details are received on multiple ports.
5. The PXE client chooses the DHCP offer from one of the ports and uses that port for further PXE boot communication, such as accessing the OS configuration file and so on.
   NOTE: Some of the PXE clients shut down ports that are not used for PXE booting.
   1. Most of the PXE clients do not support switching before a PXE boot. As a result, data loops do not form between the SmartFabric OS10 nodes and PXE clients on or before PXE boot process. For such cases, Dell Technologies recommends enabling port-fast on the LACP individual port channel that connects to the PXE client.
   2. If the PXE client supports Layer two switching before the PXE booting, you must enable xSTP (port-fast disabled) on the LACP individual port channel.
6. After receiving the SmartFabric OS10 and configuration files, the PXE client reboots and comes up with SmartFabric OS10.