CCNA学习笔记4--Telnet实验

实验拓扑

 

实验目的：

1. 掌握配置Telnet的相关命令

2. 通过观察抓取的包，得到Telnet使用的是23号端口，每次会话是随机获取的源端口

 

实验步骤：

 

1.基本配置

Router>enable

Router#configure terminal

R1(config)#enable password cisco

Router(config)#no ip domain lookup

 

Router(config)#line console 0

Router(config-line)#password cisco

Router(config-line)#logging synchronous

Router(config-line)#exec-timeout 0 0

 

Router(config-line)#line vty 0 4

Router(config-line)#password cisco

Router(config-line)#logging synchronous

Router(config-line)#exit

 

Router(config)#hostname R1

R1(config)#^Z

 

R1#wr

R1#show running-config

2.每台路由器上每个端口配置相应的ip地址

R1(config)#interface ethernet 0/0

R1(config-if)#ip address 10.0.12.1 255.255.255.0

R1(config-if)#no shutdown

 

R2(config)#interface ethernet 0/0

R2(config-if)#ip address 10.0.12.2 255.255.255.0

R2(config-if)#no shutdown

R2(config)#interface ethernet 0/1

R2(config-if)#ip address 10.0.23.2 255.255.255.0

R2(config-if)#no shutdown

 

R3(config)#interface ethernet 0/0

R3(config-if)#ip address 10.0.23.3 255.255.255.0

R3(config-if)#no shutdown

 

3配完地址之后一定要做的事情是测验直连是否通

R2#ping 10.0.12.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.12.1, timeout is 2 seconds:

.!!!!

Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/1 ms

R2#ping 10.0.23.3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.23.3, timeout is 2 seconds:

.!!!!

Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/1 ms

R1#ping 10.0.12.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.12.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

R1#ping 10.0.23.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.23.2, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

R1#ping 10.0.23.3

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.0.23.3, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

4.在三个路由器上全部启动Telnet功能

R1(config)#line vty 0 4

R1(config-line)#transport input telnet  

R1(config-line)#login

R1(config-line)#password node-R1

5.打开抓包工具

 

6.在R1上Telnet R2，再用R2 Telnet R3.这样就能在R1上操作R3了

R1#telnet 10.0.12.2

Trying 10.0.12.2 ... Open

User Access Verification

Password:

R2>enable

Password:

R2#telnet 10.0.23.3

Trying 10.0.23.3 ... Open

User Access Verification

Password:

R3>enable

Password:

R3#

7.查看抓的包。这里基本应该提取出的信息是Telnet使用的是23号端口，而源端口是随机分配的。

 

8.在R2上查看有谁Telnet我

R2#show users

    Line       User       Host(s)              Idle       Location

*  0 con 0                idle                 00:00:00   

   2 vty 0                10.0.23.3            00:07:14 10.0.12.1