Step 1. Static routing¶
Our goal in this step is to familiarize ourselves with the experimental network topology. We will not use RIP first, but will get the Ipv4NetworkConfigurator module’s help to calculate the routes and fill in the routing tables accordingly at the start of the simulation. The routing tables will not change during the simulation. Ipv4NetworkConfigurator has another task as well: It assigns IP and MAC addresses to the network interfaces, which can be a very tedious process if we do it manually.
Our network consists of three switched LANs. We use routers to connect these LANs to form an internetwork as shown in the figure below:
RipNetworkA.ned file defines this topology (see link at bottom).
We test the routing tables by sending ping packets from
experiment is set up in the
omnetpp.ini file, in the
[Config Step1] description = "Static routing" network = RipNetworkA # do not add direct routes *.configurator.addDirectRoutes = false # Application parameters *.host0.numApps = 1 *.host0.app.typename = "PingApp" *.host0.app.destAddr = "host6" *.*.ipv4.arp.typename = "GlobalArp" # Visualizer settings *.visualizer.interfaceTableVisualizer.displayInterfaceTables = true
At the start of the simulation, the configurator module does the
hard work, assigns addresses to the network interfaces, and by using its
built-in magic, fills in routing tables with the right entries. As the
simulation progresses, we see that the ping packets generated by
their way to
host6 through the LAN switches and routers through the shortest
paths as set. The following video demonstrates this.
In the video, routes towards
host0 are displayed as red arrows
and routes towards
host6 as blue arrows, as can be seen in the next screenshot:
Next, we will use our network to start experimenting with the RIP implementation.