How to Start OSPF Routing Projects Using OMNeT++

To start an Open Shortest Path First (OSPF) routing project using OMNeT++, we requires replicating a network in which routers swap OSPF routing data and find the optimal route to attain the each destination within the network. OMNeT++ network environment offers a framework like INET that encompasses models for routing protocols such as OSPF, to replicate the behavior of OSPF within a network.

Following is a sequential outline on how to get started with an OSPF Routing project in OMNeT++:

Steps to Start OSPF Routing Project in OMNeT++    

Step 1: Install OMNeT++ and INET Framework

  1. Download OMNeT++:
    • We should download and install the new version of OMNeT++ on the system.
  2. Download INET Framework:
    • INET is a popular simulation framework for OMNeT++, which has models for network protocols with OSPF.
    • We can install INET or via OMNeT++ module manager.
    • If we are unaccustomed with this step then utilise the provided INET guidance on the INET framework website.
  3. Verify Installation:
    • When installed OMNeT++ and INET then make a basic example project to make sure that everything is properly configured. We need to execute a simple simulation like a basic network of two hosts to verify if the software is functioning correctly.

Step 2: Create a New OMNeT++ Project for OSPF Routing

  1. Create a New OMNeT++ Project:
    • To navigate File > New > OMNeT++ Project and make a new project and name it as OSPF_Routing in the OMNeT++ IDE.
  2. Create Network Topology:
    • OSPF functions within an IP network in which routers swap routing data. We can make a network including several routers and connected hosts for replicating OSPF.
    • Below is a basic network topology for OSPF including numerous routers and associated hosts. OSPF will modernize the routing table dynamically to determine the optimal path.

Example of a basic OSPF network:

network OSPFNetwork {

submodules:

router1: OSPFRouter;

router2: OSPFRouter;

router3: OSPFRouter;

host1: Host;

host2: Host;

host3: Host;

connections:

host1.ethg++ <–> EthernetInterface <–> router1.ethg++;

router1.ethg++ <–> EthernetInterface <–> router2.ethg++;

router2.ethg++ <–> EthernetInterface <–> router3.ethg++;

router3.ethg++ <–> EthernetInterface <–> host3.ethg++;

host2.ethg++ <–> EthernetInterface <–> router2.ethg++;

}

In this case:

  • It has three routers are router1, router2, and router3, to build an OSPF domain.
  • The routers are linked to each other and to hosts such as host1, host2, host3.

Step 3: Configure OSPF Routing in the Network

OMNeT++’s INET framework offers an OSPF execution, which we can be utilised within the project. We can set the OSPF within network on the routers.

  1. Router Configuration:
    • In INET framework, OSPF is executed like a portion of the OSPFv2 module that we can be utilised to set the OSPF routing protocol.

Example configuration for OSPF in omnetpp.ini:

network = OSPFNetwork

sim-time-limit = 100s

[Config OSPF]

*.router1.routingProtocol = “OSPF”

*.router2.routingProtocol = “OSPF”

*.router3.routingProtocol = “OSPF”

*.router1.OSPF.areaId = 0

*.router2.OSPF.areaId = 0

*.router3.OSPF.areaId = 0

# Set the OSPF timers (Hello, Dead, and Refresh intervals)

*.router1.OSPF.helloInterval = 10s

*.router1.OSPF.deadInterval = 40s

*.router1.OSPF.refreshInterval = 30s

*.router2.OSPF.helloInterval = 10s

*.router2.OSPF.deadInterval = 40s

*.router2.OSPF.refreshInterval = 30s

*.router3.OSPF.helloInterval = 10s

*.router3.OSPF.deadInterval = 40s

*.router3.OSPF.refreshInterval = 30s

# Enable IP addressing and configure IP addresses for the routers

*.router1.ipAddress = “192.168.1.1”

*.router2.ipAddress = “192.168.2.1”

*.router3.ipAddress = “192.168.3.1”

In this set up:

  • The OSPF protocol is allowed on routers like router1, router2, and router3.
  • OSPF hello, dead, and refresh intervals are set up.
  • IP addresses are configured within the network for the routers.
  1. OSPF Area Configuration:
    • OSPF offers numerous areas for routing. In the above instance, every router is a member of area 0 that called backbone area.
    • We can be set several areas as required which is particularly in more complex networks.

Step 4: Define the Hosts and Generate Traffic

We will need to make traffic among the hosts to experiment the OSPF routing in a normal OSPF simulation. We can be utilised a basic ping or UDP application to make traffic.

Example configuration for ping traffic among hosts:

*.host1.app[0].typename = “PingApp”

*.host1.app[0].destAddr = “host2”

*.host1.app[0].startTime = 1s

*.host1.app[0].messageLength = 64B

*.host1.app[0].numMessages = 1

*.host2.app[0].typename = “PingApp”

*.host2.app[0].destAddr = “host3”

*.host2.app[0].startTime = 2s

*.host2.app[0].messageLength = 64B

*.host2.app[0].numMessages = 10

In this case:

  • Host1 transmits ping demands to Host2.
  • Host2 forwards ping requests to Host3.

These pings will be transmitted via routers depends on the OSPF routing table.

Step 5: Run the Simulation

  1. Compile the Project:
    • After configuring the set up and script the essential code as modified any modules then execute the project.
  2. Start the Simulation:
    • Execute the simulation to utilise Tkenv which is OMNeT++’s graphical interface. We will visualize a graphical representation of the network within Tkenv, in which we need to monitor how OSPF routers swap routing data and how traffic is transmitted among the hosts.
  3. Monitor the Routing Process:
    • Monitor the OSPF routing process to utilise OMNeT++ logging through the EV macro. We have to record after OSPF routers transmit and obtain the Hello packets, LSA (Link State Advertisement) updates, and routing table updates.

Example logging code in a router module:

EV << “Sending OSPF Hello packet on interface ” << interfaceId << endl;

EV << “OSPF Router ” << getId() << ” updated its LSDB” << endl;

  1. Analyze the Results:
    • When the simulation is executed then we can examine how successfully OSPF met and whether packets attained its destinations based on the expected routing paths.
    • OMNeT++ provides tools to envision the packet flows and analyse the routing tables of each router.

Step 6: Extend and Optimize the Simulation

  1. Introduce Network Failures:
    • Experiment the OSPF’s resilience for replicating network failures like as link or router failures, and then we monitor how OSPF reconverges determining the new ideal paths.
  2. Optimize OSPF Parameters:
    • Test with various OSPF hello and dead intervals, and experiment the impact over convergence time.
    • Integrate additional routers and networks for replicating larger OSPF networks.
  3. Measure Performance:
    • Estimate how effectively OSPF manages the changes to utilise the performance parameters such as convergence time, traffic overhead, and packet loss within the network topology.

Step 7: Advanced Topics

  1. Multiple Areas:
    • If we are functioning on a larger project then we need to replicate OSPF networks including several areas and experiment OSPF inter-area routing.
  2. OSPF with Authentication:
    • OSPF offers routing updates authentication to make sure security. We can prolong the replication to experiment OSPF including MD5 authentication.
  3. OSPF Cost and Path Selection:
    • OSPF utilises the costs which are linked with links for determining the shortest path. We need to test with diverse link costs and then monitor how OSPF adjusts their routes.

Conclusion

To start an OSPF Routing project using OMNeT++, we can configure the routers to swap OSPF routing data, set up the OSPF metrics, and monitor how the routers calculate the shortest path to destinations. We can set up an OSPF network and make traffic to experiment the routing behavior by utilising the INET framework that offers built-in support for OSPF. We need to prolong the simulation by inserting several OSPF areas, experimenting network failures, and enhancing the OSPF metrics.

We provided an in-depth simulation procedure for OSPF Routing Projects with OMNeT++ environment and have the capacity to expand it for more clarity if needed. Drop us all your query to get more reasech guidance.