I am using Symantec Ghost 7.0. Every time I run multicast server the network performance is reduced by more than half. So i figured if can stop the multicast packets from leaving the switch where all the clients are connected I can stop the unnecessary traffic. Allow me to explain the current scenario. There is a workbench were all stations on the work bench are connected to a Cisco Catalyst 3524. Port 24 on the catalyst is connected to a parent Switch via a cross over cable. A DHCP server and the Proxy Server are connected to the PARENT Switch, which is how the computers on the workbench get their IP addressee and access the internet. NOTE!!! ONLY computers on the workbench need to access the Symantec Multicast Server. So I think I can add an access statement to the switch to stop all outgoing packets from Symantec Multicast on Switch Port 24. The question is how does Symantec Multicast server send information to their clients, and how do the clients find the Multicast Server? Is it a particular port or a particular packet or what?