[ns] color prolem

[Sencun Zhu <szhu1@ise.gmu.edu>]

Hi, dear all:

     My problem is I can not set the color for packets  correctly. I have
looked through ns-manual and some previous related questions, I still do
not know why it does not work correctly in my case. the below is a simple
example using centralized multicast:

    $ns color 0  blue
    $ns color 1  green
    set udp [new Agent/UDP]
    $ns attach-agent $n($startnode) $udp
    set src [new Application/Traffic/CBR]
    $src  set packetSize_ 500
    $src  set interval_ 0.005
    $src set packetSize_ 536
    $src attach-agent $udp
    $ns at 0.5 "$src start"

    $udp set dst_addr_ $group
    $udp set dst_port_ 1
    $udp set fid_  1
    $n($startnode) color red
    $n($startnode) shape square

 there are also many receivers in this group. I saw all packets' color is
blue, but when a node drops packets, some of packets are blue, some are
green. 

any suggestion?

thank you

Sencun