Multicast
To test Multicasting Environment: FOG server two or more identical PC Ethernet hub or FastEthernet switch in same VLAN. to view Multicat status on server use tty2 or /opt/fog/log/muliticat.log overall image time will be slower then unicast on same hardware and same image because unicast is gunzip(unzip) at client level, multicast in gunzip at server level. If error persistent in test environment post log in forum.
More Info on Multicasting Multicasting