packet-generator new {
  name x
  limit 1
  node ip4-input
  size 512-512
  data {
    ICMP: 1.0.0.2 -> 232.1.1.1
    ICMP echo_request
    incrementing 100
  }
}

create packet-generator interface pg1
create packet-generator interface pg2
create packet-generator interface pg3

set int state pg1 up
set int state pg2 up
set int state pg3 up

ip mroute add 232.1.1.1 via pg0 Accept
ip mroute add 232.1.1.1 via pg1 Forward
ip mroute add 232.1.1.1 via pg2 Forward
ip mroute add 232.1.1.1 via pg3 Forward