MDs Do Not Network (PXE) Boot

You have a working Core/Hybrid and network - you start a new PC on the LMCE (internal) network, and you tell it to network boot (PXE) so that you can use it was an Media Director. The boot process starts but the PC does not successfully boot as a Media Director.

There are many reasons why this may happen:

Using a manageable switch with STP, where the ports are Blocking (eg Cisco enterprise switches)

Many switches use Spanning Tree Protocol (STP) which by default sets a port to "Blocking" and other non-Forwarding states for the first 50 seconds after a computer, connected to it, comes online. This is to allow time for the switch to confirm that there is no loop in your network related to that port, and during this period it will not pass any packets onto the rest of the LAN. This means your MD's network (PXE) boot process will almost certainly timeout and fail before the port goes into its Forwarding state. Power off/on, and in most cases, rebooting will simply restart the STP timer and end in the same timeout.

Assuming that you definitely do not have any loops in your network, you can bypass this checking process by configuring that port. Never do this to a port that connects to another switch - setting up a loop between switches or to the same switch, without this check can paralyse your network. For a Cisco switch, connect to your switch's management IP address with telnet and type:

enable

config t

interface e1/0 <- change e1/0 to the port's blade and port number

portfast enable

exit

write

[Can someone please correct these instructions?]

Then disconnect your telnet session.