But this is not the proper way to setup PXE, and doing so is not supported by Microsoft as per KB #259670.
PXE is a great example of a topic that turns up a ton of search results but very little helpful content.
Search for “PXE configuration” or “PXE troubleshooting” and you’ll find the majority of posts focus on the same thing, specifically a few DHCP options that “must” be set in order for PXE to work.
If your DHCP server(s) is on a different VLAN from your clients, your router will need to be configured as a DHCP relay; on Cisco equipment this is done through the command. Anyway, that’s the basic DHCP traffic flow, but it’s important to recognize that the initial DHCP Discover includes requests for quite a few parameters, as shown below via a Wireshark capture.
Note options 60, 66, and 67, Vendor Class Identifier, TFTP server name and Bootfile Name.
Additionally, in some cases if your PXE server is down, your client PCs may hang up – either briefly or indefinitely – while looking for it.