iPXE stalls during HTTP ISO Boot when accessing an LACP connected server.

[jpwise]

Not my area of expertise, but it does sound very similar to some issues I encountered a couple of weeks ago setting up an iPXE boot server in one of our other branches. After doing a tcpdump we traced it to the Cisco switch using STP (Spanning Tree Protocol) resulting in a ~60 second delay with bringing the port online after initial link.

Similarly to what you experienced it wasn't an issue from a VM running in bridge mode if the host machine was already connected to the port (and having sat through the delay already).

I'd speculate it's probably a similar issue with the switch checking for a loop to prevent flooding the network. Could give you a starting point to troubleshoot it further at any rate.

From memory if you plug a dumb switch into the port and then plug the iPXE client machine in 'behind' the dumb switch that also worked.

Jp.