## First Multicast group# 2 sender: nodes 0 and 1# receiver(s): nodes 20 through 99#for {set i 0} {$i < 2} {incr i} {	set udp_($i) [new Agent/UDP]	$udp_($i) set dst_addr_ 0xE000000	$ns_ attach-agent $node_($i) $udp_($i)#	set cbr_($i) [new Application/Traffic/CBR]	$cbr_($i) set packetSize_ 256	$cbr_($i) set interval_ 0.50	$cbr_($i) set random_ 1	# send enough packets to keep simulation nearly busy: 2 packets	# a second, starting at 30, stopping at 899: 2*870 = 1740	$cbr_($i) set maxpkts_ 1740	$cbr_($i) attach-agent $udp_($i)	$cbr_($i) set dst_ 0xE000000	$ns_ at 30.0 "$cbr_($i) start"}## the nodes have to join the multicast group to receive the packet...#for {set i 20} {$i < 100} {incr i} {	$ns_ at 0.0100000000 "$node_($i) flood-join-group 0xE000000"}