DTEK8060 Programming Project

Overview

A console-based simulator for understanding BGP-style routing behavior.
Users input router topology and can send messages between routers, which are forwarded along the shortest available path.

classDiagram
    class Router {
        - name: String
        - ipAddress: String
        - port: int
        - routingTable: Map<Integer, Router>
        - neighbors: List<Router>
        - coldStart: boolean
        - serverSocket: ServerSocket
        + start()
        + discoverNeighbors(NetworkTopology)
        + buildRoutingTable()
        + updateRoutingTable(Map, Router)
        + processPacket(IPPacket)
        + sendMessage(int, String)
        + forwardPacket(List, String)
        + receivePacket(List, String)
    }

    class NetworkTopology {
        - topology: Map<Router, List<Router>>
        + addRouter(Router)
        + addConnection(Router, Router)
        + getNeighbors(Router): List
        + computeShortestPath(Router, Router): List
    }

    class IPPacket {
        - sourceIP: String
        - destinationPort: int
        - message: String
        + getSourceIP()
        + getDestinationPort()
        + getMessage()
    }

    class TrustManager {
        - trustValues: Map<Router, Integer>
        + setTrust(Router, int)
        + getTrust(Router): int
        + voteTrust(Router, Router, int)
    }

    class BGPProtocol {
        + handleMessage(String, Router, Router)
        + establishConnection(Router, Router)
    }

    class ErrorSimulator {
        + simulateRouterFailure(Router)
        + simulateLinkFailure(NetworkTopology, Router, Router)
    }

    Router --> NetworkTopology : uses
    Router --> TrustManager : uses
    Router --> IPPacket : processes
    Router --> BGPProtocol : uses
    NetworkTopology --> Router : contains
    ErrorSimulator --> Router : simulates
    ErrorSimulator --> NetworkTopology : affects
    TrustManager --> Router : trusts

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This is a BGP (Border Gateway Protocol) simulator project that can be executed as a standalone Java application.
Users can run the simulator by downloading the compiled .jar file and following the instructions below.

Prerequisites

Before running the BGP Simulator, make sure you have the following:

Java Runtime Environment (JRE)

You need Java 17 or higher installed on your system.

Check your version with:

java -version

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Setup & Run Instructions

1. Clone the Repository

git clone https://github.com/leotamminen/network_routing_project
cd network_routing_project

2. Run the Program

java -jar bgpsimulator-1.0-SNAPSHOT.jar

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Usage

1. Run the program and input the number of routers.
2. Manually enter the neighbors for each router (e.g., 2,3).
3. Specify the router number from which to send the message (e.g., 5).
4. Enter the destination router number (e.g., 6).
5. Type the message — it will be routed along the shortest path.

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Demonstration of a 7-router topology:

graph  TD;
Router1  --> Router2

Router1  --> Router3

Router1  --> Router7

Router2  --> Router4

Router2  --> Router6

Router3  --> Router5

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Enter the number of routers: 7
Enter neighbors for Router1 (comma separated, e.g., 2,3): 2,3,7
Enter neighbors for Router2 (comma separated, e.g., 2,3): 1,4,6
Enter neighbors for Router3 (comma separated, e.g., 2,3): 1,5
Enter neighbors for Router4 (comma separated, e.g., 2,3): 2
Enter neighbors for Router5 (comma separated, e.g., 2,3): 3
Enter neighbors for Router6 (comma separated, e.g., 2,3): 2
Enter neighbors for Router7 (comma separated, e.g., 2,3): 1
...
Enter the router number to send messages from: 5
Enter destination router number (or type 'exit' to quit): 6
Enter your message: hello
...
Routing packet via: [com.bgpsimulator.router.Router@6193b845, com.bgpsimulator.router.Router@1f17ae12, com.bgpsimulator.router.Router@76fb509a, com.bgpsimulator.router.Router@300ffa5d, com.bgpsimulator.router.Router@2e817b38]
Router5 forwarding packet to Router3
Router3 forwarding packet to Router1
Router1 forwarding packet to Router2
Router2 forwarding packet to Router6
Packet arrived at destination: Router6 with message: hello
Enter destination router number (or type 'exit' to quit):