port mirroring and multicast

Hi,

I am trying to do some test of multicast in local network. The scenario I am trying to test is as follows:

1. Server 1 is the source of multicast traffic and it sends multicast to group 239.1.1.1. Server 2 is on the same VLAN and is able to receive multicast from group 239.1.1.1. Both Server 1 and Server 2 use iperf for the test. 

2. Then I configured port mirroring on powerconnect 6248 switch. The source port is configured as the port Server 2 is connected, and destination port (which is on another VLAN) is the port another server (Server  3) is connected. 

3. I am expecting to receive the same multicast on Server 3. However, I cannot receive any multicast either using iperf or tcpdump.

No multicast routing protocol configured. No igmp snooping enabled. 

Any help is appreciated.

Calvin