PXEboot Discovery for version 6.2.12

I am trying to get Discovered Hosts to work. We have setup the network with external DNS and DHCP and have every thing configured on both the network and satellite server with Discovery and have updated the default templates but the hosts are not being discovered.

In a network trace we can see the packets coming across the network and none of the packets are blocked by firewalls or selinux.

When we boot the servers the are assigned all appropriate network information. We have booted more than one to make sure ip assignments work as expected and they do.

I can't figure out why Satellite is not seeing them. The client hosts eventually time out.

Has anyone gotten this to work? Any help would be greatly appreciated.