30 import ns.internet_apps
    38     cmd = ns.core.CommandLine();
    43     print (
"Create nodes")
    44     n0 = ns.network.Node();
    45     r = ns.network.Node();
    46     n1 = ns.network.Node();
    48     net1 = ns.network.NodeContainer();
    51     net2 = ns.network.NodeContainer();
    54     all = ns.network.NodeContainer();
    60     internetv6 = ns.internet.InternetStackHelper();
    61     internetv6.Install(all);
    64     csma = ns.csma.CsmaHelper();
    65     csma.SetChannelAttribute(
"DataRate", ns.network.DataRateValue(ns.network.DataRate(5000000)));
    66     csma.SetChannelAttribute(
"Delay", ns.core.TimeValue(ns.core.MilliSeconds(2)));
    67     d1 = csma.Install(net1);
    68     d2 = csma.Install(net2);
    72     ipv6 = ns.internet.Ipv6AddressHelper();
    73     ipv6.SetBase(ns.network.Ipv6Address(
"2001:1::"), ns.network.Ipv6Prefix(64));
    75     i1.SetForwarding(1, 
True);
    76     i1.SetDefaultRouteInAllNodes(1);
    77     ipv6.SetBase(ns.network.Ipv6Address(
"2001:2::"), ns.network.Ipv6Prefix(64));
    79     i2.SetForwarding(0, 
True);
    80     i2.SetDefaultRouteInAllNodes(0);
    86     interPacketInterval = ns.core.Seconds(1.);
    87     ping6 = ns.internet_apps.Ping6Helper();
    89     ping6.SetLocal(i1.GetAddress(0, 1));
    90     ping6.SetRemote(i2.GetAddress(1, 1)); 
    92     ping6.SetAttribute(
"MaxPackets", ns.core.UintegerValue(maxPacketCount));
    93     ping6.SetAttribute(
"Interval", ns.core.TimeValue(interPacketInterval));
    94     ping6.SetAttribute(
"PacketSize", ns.core.UintegerValue(packetSize));
    96     apps = ping6.Install(ns.network.NodeContainer(net1.Get(0)));
    97     apps.Start(ns.core.Seconds(2.0));
    98     apps.Stop(ns.core.Seconds(20.0));
   101     ascii = ns.network.AsciiTraceHelper()
   102     csma.EnableAsciiAll(ascii.CreateFileStream(
"simple-routing-ping6.tr"))
   103     csma.EnablePcapAll(
"simple-routing-ping6", 
True)
   106     ns.core.Simulator.Run()
   107     ns.core.Simulator.Destroy()
   109 if __name__ == 
'__main__':