网络路由器查表过程模拟

llb123 2021-08-30 原文

任务及要求
编程模拟路由器查表过程，用(目的地址掩码下一跳)的IP路由表以及目的地址作为输入，为目的地址查找路由表，找出正确的下一跳并输出结果。
1.
建立一个路由表
在这里插入图片描述

f=open(\'路由表.txt\',\'r\')
list1=[]
i=0
while(1):
    y=f.readline()
    if y==\'\':
        break
    list1.append(y)
f.close()

while(1):
    z=input("目的IP地址：")
    x=z.split(\'.\')


    for i in range(2,len(list1)):
        a=list1[i].split()
        q=a[1].split(\'.\')
        e=a[2].split(\'.\')
        if a[0]==\'1\':
            if((int(x[0])&int(e[0])==int(q[0])) and (int(x[1])&int(e[1])==int(q[1])) and (int(x[2])&int(e[2])==int(q[2])) and (int(x[3])&int(e[3])==int(q[3]))):
                print("直接交付",a[3])
                break
             else:
                if ((int(x[0])&int(e[0])==int(q[0])) and (int(x[1])&int(e[1])==int(q[1])) and (int(x[2])&int(e[2])==int(q[2])) and (int(x[3])&int(e[3])==int(q[3]))):
                    print("间接交付，下一跳为：",a[3])
                    break
                else:
                    continue
        else:
            if ((int(x[0])&int(e[0])==int(q[0])) and (int(x[1])&int(e[1])==int(q[1])) and (int(x[2])&int(e[2])==int(q[2])) and (int(x[3])&int(e[3])==int(q[3]))):
                print(a[3])
                break
            else:
                print("转发分组出错！")
                break