How to Begin Implement IPv6 Protocols in NS3

To begin implementing IPv6 protocols within NS3, we can apply the Ipv6RoutingProtocol class and relevant IPv6 components. IPv6 execution is theoretically same to IPv4 however it has more difficulties like managing the larger addresses, multicast, and Neighbor Discovery Protocol (NDP).

Below is a comprehensive instruction to get started:

Steps to Begin Implement IPv6 Protocols in NS3

Step 1: Understand IPv6 in NS3

1. Core IPv6 Components:
   • Ipv6RoutingProtocol: It is a base class in NS3 for custom IPv6 routing protocols.
   • Ipv6L3Protocol: Manages the IPv6 layer operations like sending and handling header.
   • Ipv6Address: It denotes the IPv6 addresses.
   • Ipv6Header: Signifies IPv6 packet headers.
   • NdiscCache: For address resolution, executes the Neighbor Discovery Protocol (NDP).
2. Existing Protocols: Focus on the existing IPv6 routing protocols utilising NS3 like:
   • StaticRouting: For basic static route sets up, these protocols are used.
   • RoutingHelper Classes: Helper classes to incorporate the routing protocols.

Step 2: Set Up NS3

1. Install NS3: Clone and construct NS3 including samples are facilitated:

git clone https://gitlab.com/nsnam/ns-3-dev.git

cd ns-3-dev

./ns3 configure –enable-examples –enable-tests

./ns3 build

1. Verify Installation: Execute an instance simulation script to confirm the set up:

./ns3 run examples/tutorial/first

Step 3: Plan the IPv6 Protocol

1. Define Protocol Goals:
   • Describe the IPV6 protocol objectives like decide on it distance-vector, link-state, or a custom routing protocol.
   • Routing parameters are leveraged for route selection such as latency, bandwidth.
2. Key Features:
   • IPv6-specific aspects such as address scopes such as link-local, global.
   • Route discovery and maintenance.
   • Multicast and Neighbor Discovery Protocol (NDP) managing.

Step 4: Implement the IPv6 Protocol

Step 4.1: Create a Custom Protocol Class

We need to make a new protocol class to prolong the Ipv6RoutingProtocol class:

#include “ns3/ipv6-routing-protocol.h”

#include “ns3/node.h”

#include “ns3/socket.h”

using namespace ns3;

class MyIpv6Protocol : public Ipv6RoutingProtocol {

public:

static TypeId GetTypeId(void);

MyIpv6Protocol();

virtual ~MyIpv6Protocol();

// Override required methods

virtual Ptr<Ipv6Route> RouteOutput(Ptr<Packet> packet, const Ipv6Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) override;

virtual bool RouteInput(Ptr<const Packet> packet, const Ipv6Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) override;

virtual void NotifyInterfaceUp(uint32_t interface) override;

virtual void NotifyInterfaceDown(uint32_t interface) override;

virtual void NotifyAddAddress(uint32_t interface, Ipv6InterfaceAddress address) override;

virtual void NotifyRemoveAddress(uint32_t interface, Ipv6InterfaceAddress address) override;

private:

void UpdateRoutingTable();

void HandleIncomingPacket(Ptr<Packet> packet, const Ipv6Header &header);

};

Step 4.2: Implement Protocol Logic

• Routing Output (Forwarding Decisions): Manage outgoing packets that are transmitted.

Ptr<Ipv6Route> MyIpv6Protocol::RouteOutput(Ptr<Packet> packet, const Ipv6Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) {

// Lookup or compute the route for the packet

Ptr<Ipv6Route> route = Create<Ipv6Route>();

route->SetDestination(header.GetDestinationAddress());

route->SetSource(header.GetSourceAddress());

route->SetGateway(Ipv6Address(“2001:db8::1”)); // Example gateway

route->SetOutputDevice(oif);

return route;

}

• Routing Input (Incoming Packets): Control received packets using the node.

bool MyIpv6Protocol::RouteInput(Ptr<const Packet> packet, const Ipv6Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) {

// Check if the packet is for this node

if (header.GetDestinationAddress() == GetNode()->GetObject<Ipv6>()->GetAddress(1, 0).GetAddress()) {

lcb(packet, header, idev); // Deliver locally

return true;

}

// Forward the packet

Ptr<Ipv6Route> route = LookupRoute(header.GetDestinationAddress());

if (route) {

ucb(route, packet, header);

return true;

}

ecb(packet, header, Socket::ERROR_NOROUTETOHOST);

return false;

}

• Handle Interface and Address Events: Modernize the protocol if modify the interfaces or IP addresses.

void MyIpv6Protocol::NotifyInterfaceUp(uint32_t interface) {

// Handle interface up events

}

void MyIpv6Protocol::NotifyAddAddress(uint32_t interface, Ipv6InterfaceAddress address) {

// Add address to routing table

}

Step 5: Integrate the Protocol

Step 5.1: Register the Protocol

Record the IPV6 protocol including NS3’s TypeId system:

TypeId MyIpv6Protocol::GetTypeId(void) {

static TypeId tid = TypeId(“ns3::MyIpv6Protocol”)

.SetParent<Ipv6RoutingProtocol>()

.SetGroupName(“Internet”)

.AddConstructor<MyIpv6Protocol>();

return tid;

}

Step 5.2: Add to Nodes

Integrate the protocol toward nodes with InternetStackHelper:

#include “ns3/internet-stack-helper.h”

int main(int argc, char *argv[]) {

NodeContainer nodes;

nodes.Create(3);

InternetStackHelper stack;

Ptr<MyIpv6Protocol> myRouting = CreateObject<MyIpv6Protocol>();

stack.SetRoutingHelper(myRouting);  // Use your custom protocol

stack.Install(nodes);

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 6: Test and Debug

1. Set Up a Simulation:
   • Make a network topology with the support of PointToPointHelper or CsmaHelper.
   • Set up IPv6 traffic sources such as UdpEchoClient.
2. Enable Logging: Make use of NS3’s logging system for debugging:

export NS_LOG=”MyIpv6Protocol=level_all|prefix_time”

./ns3 run my-simulation

1. Analyze Results:
   • Accumulate and examine the performance parameters leveraging FlowMonitor.
   • With the help of PcapHelper to seizure and analyse the packets.

Step 7: Optimize and Extend

1. Performance Optimization:
   • Enhance route to get better mechanisms for large-scale simulations.
   • Apply caching strategies for minimizing the reiterated route computations.
2. Feature Enhancements:
   • Incorporate support for multicast or QoS-aware routing.
   • Execute the probabilistic or hybrid routing mechanisms.

Overall, we covered the valuable insights through the simple method to implement and extend the IPv6 Protocols using NS3 simulation environment. If needed, we will also offer the additional details through another manual.