@jgiovann Great you figured this is a spanning treee thing! Seems like I was to focused on the issue might be routing problems that I didn’t notice the message udhcpc: no lease, failing.
In a real production network (where turning off spanning tree is not be allowed), is it therefore possible to re-configure the FOG server to wait longer or retry more times before it gives up the registration retry loop ?
The problem cannot be solved in the registration retry loop I think but we’d need to tell the dhcp client to wait longer. But from my point of view you should be able to solve this by setting the client ports to “port fast”. There er different names for this but what it essentially does is disable spanning tree for particular ports where you surely know there are no other switches connected but only clients. On those ports you never ever need spanning tree because single clients connected to a port can never cause a loop (which spanning tree was invented to prevent from)!