proc ConfigIgmpSourceMode { igmpSessionHandle mode } {
    # igmpSessionHandle: ::ixNet::OBJ-/vport:1/protocols/igmp/host:3/group:3
    # mode: include or exclude

    # Usage example:
    #    -mode create
    #    -session_handle ::ixNet::OBJ-/vport:1/protocols/igmp/host:3
    #    -source_pool_handle [list source1 source2] 
    #    -group_pool_handle group3 

    puts  "\nConfigIgmpSourceMode: $igmpSessionHandle"
    ixNet setAttribute $igmpSessionHandle -sourceMode $mode
    ixNet commit
}