RIP路由选择算法
一、实验目的
模拟 RIP 路由选择算法的工作原理。
二、实验内容
针对上述网络结构，模拟 RIP 路由选择算法的工作原理，包括各个路由表的 建立更新过程，设计简单的图形界面。
三、实验原理
1.路由器刚启动时，对其路由表进行初始化。
2.路由表建立后，路由器周期性地向相邻路由器广播自己的路由表信息。假 设 R1,R2 是一个自治系统中两个相邻的路由器。如果 R1 中没有这项纪录，R1 在 路由表中增加该项，由于要经过 R2 转发，所以距离加 1；如果 R1 路由表中的一 项记录比 R2 发送的一项记录距离值减一还要大，R1 则在路由表中修改该项，距 离根据 R2 提供的值再加 1。 3.RIP 路由更新算法中，每隔 30 秒在相邻的路由器之间减缓依稀路由更新信 息，产生一个随机延迟信息，当记录在 180 秒内没有收到刷新信息时，，路由器 将该记录置为无效，如果无效的记录持续时间超过 120 秒，则请出该项信息。
四、实验代码
1.Client类：
package RIM;
public class Client {
public static StringBuffer source = new StringBuffer();
public static StringBuffer aim = new StringBuffer();
public static final int SUM = 10;
private static Router[] routers = createRouter();
public static void makeAll() {
for(Router r : routers){
source.append(r.getInfo());
}
for(Router r : routers)
r.send();
for(Router r : routers){
aim.append(r.getInfo());
}
}
public static void refresh(){
source = new StringBuffer();
for(Router r : routers){
source.append(r.getInfo());
}
for(Router r : routers)
r.send();
aim = new StringBuffer();
for(Router r : routers){
aim.append(r.getInfo());
}
}
public static Router[] createRouter(){
Router[] routers = new Router[SUM];
for (int i = 0; i < SUM; i++){
routers[i] = new Router("Router"+i);
}
routers[1].setCon(routers[2],routers[4]);
routers[1].initList(new Item("1.2.0.0"),new Item("1.4.0.0"));
routers[2].setCon(routers[1],routers[3],routers[5],routers[6]);
routers[2].initList(new Item("1.2.0.0"),new Item("2.3.0.0"),new Item("2.5.0.0"),new Item("2.6.0.0"));
routers[3].setCon(routers[2],routers[4],routers[6],routers[9]);
routers[3].initList(new Item("2.3.0.0"),new Item("3.4.0.0"),new Item("3.6.0.0"),new Item("3.9.0.0"));
routers[4].setCon(routers[1],routers[3],routers[7]);
routers[4].initList(new Item("1.4.0.0"),new Item("3.4.0.0"),new Item("4.7.0.0"));
routers[5].setCon(routers[2],routers[8]);
routers[5].initList(new Item("2.5.0.0"),new Item("5.8.0.0"));
routers[6].setCon(routers[2],routers[3],routers[8],routers[9]);
routers[6].initList(new Item("2.6.0.0"),new Item("3.6.0.0"),new Item("6.8.0.0"),new Item("6.9.0.0"));
routers[7].setCon(routers[4],routers[9]);
routers[7].initList(new Item("4.7.0.0"),new Item("7.9.0.0"));
routers[8].setCon(routers[5],routers[6],routers[9]);
routers[8].initList(new Item("5.8.0.0"),new Item("6.8.0.0"),new Item("8.9.0.0"));
routers[9].setCon(routers[3],routers[6],routers[7],routers[8]);
routers[9].initList(new Item("3.9.0.0"),new Item("6.9.0.0"),new Item("7.9.0.0"),new Item("8.9.0.0"));
return routers;
}
}
2.Item类：
package RIM;
public class Item {
String aimNet;
int distance;
String router;
int clock;
public Item(String aimNet){
this.aimNet = aimNet;
this.distance = 0;
this.router = "-";
this.clock = 0;
}
public Item(String aimNet,int distance,String router,int clock){
this.aimNet = aimNet;
this.distance = distance;
this.router = router;
this.clock = clock;
}
public String getAimNet() {
return aimNet;
}
public void setAimNet(String aimNet) {
this.aimNet = aimNet;
}
public int getDistance() {
return distance;
}
public void setDistance(int distance) {
this.distance = distance;
}
public String getRouter() {
return router;
}
public void setRouter(String router) {
this.router = router;
}
public int getClock() {
return clock;
}
public void setClock(int clock) {
this.clock = clock;
}
@Override
public String toString() {
return "目的网络: "+ aimNet + "\t距离: " + distance + "\t下一跳路由器: " + router;
}
}
3.Router类：
package RIM;
import java.util.ArrayList;
public class Router {
public static int time;
ArrayList<Item> list = new ArrayList<Item>();
ArrayList<Router> routerList = new ArrayList<Router>();
String name;
public Router(String name){
this.name = name;
}
public void setCon(Router ... router){
for (Router i : router){
routerList.add(i);
}
}
public void initList(Item ... items){
for (Item i : items){
this.list.add(i);
}
}
public void send(){
for (Item item : this.list){
if (item.distance != 0)
item.clock += 30;
if (item.clock > 180)
item.clock = 0;
}
for (Router router : routerList){
router.recv(this);
}
}
public void recv(Router router){
final ArrayList<Item> list = router.list;
for (Item item : list){
boolean flag = true;
for (int i = 0; i < this.list.size(); i++){
if (item.aimNet.equals(this.list.get(i).aimNet)){
flag = false;
if (item.distance < this.list.get(i).distance - 1){//更新
this.list.get(i).distance = item.distance + 1;
this.list.get(i).router = router.name;
this.list.get(i).clock = 0;
}
}
}
if (flag){
this.list.add(new Item(item.aimNet,item.distance+1,router.name,0));
}
}
}
public void printList(){
if (this.name.equals("Router0"))
return;
System.out.println(this.name + ":");
for (Item i : this.list)
System.out.println(i);
}
public String getInfo(){
StringBuffer buffer = new StringBuffer();
if (this.name.equals("Router0"))
return "";
buffer.append(this.name + " :\n");
for (Item i : this.list)
{
buffer.append(i.toString() + "\n");
}
return buffer.toString();
}
}
4.GUI类
package RIM;
import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextArea;
import javafx.scene.layout.HBox;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class GUI extends Application {
private static TextArea source = new TextArea();
private static TextArea aim = new TextArea();
private static Label pre = new Label("原始路由表:");
private static Label after = new Label("更新后的路由表");
private static Button refresh = new Button("更新路由表");
private static VBox vbox = new VBox(15);
private static HBox bar = new HBox(15);
private static Scene scene = new Scene(vbox);
@Override
public void start(Stage primaryStage) throws Exception {
bar.getChildren().addAll(pre,refresh);
vbox.getChildren().addAll(bar,source,after,aim);
vbox.setPadding(new Insets(15));
source.setText(Client.source.toString());
aim.setText(Client.aim.toString());
source.setEditable(false);
aim.setEditable(false);
refresh.setOnAction(action -> {
Client.refresh();
pre.setText("更新前的路由表:");
source.setText(Client.source.toString());
aim.setText(Client.aim.toString());
});
primaryStage.setScene(scene);
primaryStage.show();
}
public static void main(String[] args) {
Client.makeAll();
launch(args);
}
}
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