Demonstrates software defined routing using the distance vector protocol to update forwarding tables between routers.
**NOTE: Controller Program was not written by me. This program virtualizes a controller used for SDN routing. It sends and receives messages from the routers via a TCP socket communication.
This program emulates a simple SDN network with N routers. It can be run locally on one machine as long as each router ports are different and the local IP is specified. Or each router can be run seperatly on different machines. The topology files below will build the graph. Each router when started will begin listening on the TCP port specified for the controller to send the INIT file. Once the INIT file is received the router will update it's distance vector and begin sending routing updates after the specified interval.
Multiple sockets and the timer is handled using select().
Routers communicate via UDP port specified in the INIT file.
Multiple timers is implemented using one timer and the receive time of each Distance Vector update. If a router is not updated with a neighbors Distance vector for 3 consecutive update periods then that router will be considered as offline and the forwarding table will be updated this will propagate through the network.
There is an included makefile which will compile the program
The program takes one argument - the port to start the router on. This port will be the port used by the controller to initiate a TCP connection with the router.
The controller can send multiple different commands use ./controller -h
The first command that should be sent once all routers are up is the init command, this will initialize all routers. From here, the distance vector protocol will begin and after a few rounds all routers will have the updated shortest path to all other routers in the graph.
The controller must take in a topology file argument for the INIT command. The topology file contains the graph of the network. It should contain the following.
Line 1 - Number of routers (N)
Line 2 - N: Each line will represent a router with the following information
Line 3 - ?? : Each line will contain router link costs. Example 1 2 4. This means link 1 to 2 has cost 4.
Take a look at the example.topology file and the test.topology for details.
*Controller Port: This is the port the router needs to be started on. The router will listen on this port for the controller to connect.
*Router Port: This is the UDP port used for other routers to send messages to that router.
*Data Port: This is the TCP port the router will listen on for any routers trying to connect and send packets.
** Note the data plane of this program is not implemented. Currently only router distance vector updates and controller communication is working.