node link

set ns[new simulator]
set nf[open out.nam w]
$ns .namtrace-all $nf
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
$ns duplex-link $n0 $n2 2mb 10ms DropTail
$ns duplex-link $n0 $n1 2mb 10ms RED
proc finish{} {
global ns nf
$ns flush-trace
close $nf
exec nam out.nam &
exit 0
}
$ns at 5.0 "finish"
$ns run