Have you ignored our default post template where we ask for deployment details intentionally? Just asking, I don’t know what else to do to get just a tad of more information.
What kind of hypervisor or hardware your client is?
It is a Cisco UCS with intel x550 card, so it does support iPXE according to the hcl list. I am trying to install esxi7 (cisco image). I was able to install esxi7 (dell image) on a dell r730xd using the same method. But since they are in production I can not try to reproduce the problem in that environment.
I guess my expertise with pxe boot and foreman are not that great yet even I was able to do this on a dell environment (different vlan of course, but I can not tell any different settings though)
The initial DHCP was not made by iPXE but PXE, therefore it worked. The same for TFTP, it uses the UNDI stack that will always work.
Then iPXE boots up and from now on, this mini-operating system needs to have a driver for your card in order to communicate (grab a new IP, do its thing).
My conclusion: Your hardware is not supported on iPXE.
My advice: If your hardware supports UEFI HTTP Boot, use that. It supports direct HTTP(S) booting, you can use grub2 (make sure to use latest version from Fedora Rawhide) or iPXE.efi too.