Configure Telnet login for router/switch

"Experiment Name"

Configure Telnet on the router.

"Experimental Purpose"

Learn how to configure Telnet on a router to enable remote login access to the router.

"Background description"

When a router is used to connect multiple subnets, the placement is usually far apart, and it is cumbersome to view and modify the configuration, which can greatly reduce the workload of the administrator if it is possible to remotely log on to the router.

"Demand Analysis"

You need to know how to configure the password for the router, how to configure the Telnet service, and how to telnet to the router by remote login.

"Experimental Equipment"

Router (with serial port) 2 units

v.35 Dce/dte Cable 1 Pair

"Experimental principle"

Two routers through the serial port, with the v.35 Dte/dce cable connected together, respectively, configure Telnet, you can telnet to each other. The router provides a WAN interface (serial high-speed synchronous serial port) that connects the WAN interface link with the v.35 cable. On a WAN connection, one end is DCE (data communication device) and one end is DTE (data terminal device). The clock rate must be configured at the DCE end to ensure link connectivity.

"Experimental Steps"

First step: Configure the name of the router, the interface IP address, and the clock

R3740#configure Terminal

Enter configuration commands, one per line. End with cntl/z.

R3740 (config) #hostname RouterA

！ Configure the name of the router

RouterA (config) #interface serial 4/0

！ Interface configuration mode into the serial port

RouterA (config-if) #clock rate 512000

！ Set the clock frequency for the DCE end

RouterA (config-if) #ip address 192.168.1.1 255.255.255.0

！ Configure Interface IP Address

RouterA (config-if) #no shutdown

！ Enable ports

RouterA (config-if) #exit

According to the above code, we can briefly write as shown: 650) this.width=650; "Src=" http://s5.51cto.com/wyfs02/M01/87/58/ Wkiol1fejh7j4hwdaaavfc5o9-i480.jpg-wh_500x0-wm_3-wmp_4-s_245964710.jpg "title=" 1.jpg "alt=" Wkiol1fejh7j4hwdaaavfc5o9-i480.jpg-wh_50 "/>

Step Two: Configure Telnet

RouterA (config) #enable password Ruijie

！ Configure the router's privileged mode password

RouterA (config) #line vty 0 4

！ Enter thread configuration mode

RouterA (Config-line) #password star

！ Configure the Telnet password

RouterA (Config-line) #login

！ To authenticate when you set Telnet logon

RouterA (Config-line) #end

From the above can be as shown:

The first picture is set to enter privileged mode cipher graph: 650) this.width=650; "Src=" http://s4.51cto.com/wyfs02/M00/87/5B/ Wkiom1fejqainxeaaaa5ryyc7dg475.jpg-wh_500x0-wm_3-wmp_4-s_1051380498.jpg "title=" 2.jpg "alt=" Wkiom1fejqainxeaaaa5ryyc7dg475.jpg-wh_50 "/>

The second one configures the Telnet password diagram:

650) this.width=650; "Src=" Http://s2.51cto.com/wyfs02/M01/87/59/wKioL1feJw_gcff9AAAuwrxUIgA263.jpg-wh_500x0-wm_3 -wmp_4-s_1415656905.jpg "title=" 3.jpg "alt=" Wkiol1fejw_gcff9aaauwrxuiga263.jpg-wh_50 "/>

Step three: Test network connectivity and log in to the router in Telnet mode

Routerb#ping 192.168.1.1

Sending 5, 100-byte ICMP echoes to 192.168.1.1, timeout is 2 seconds: < press CTRL + C to break >

!!!!!

Success rate is percent (5/5), round-trip Min/avg/max = 1/2/10 ms

Routerb#telnet 192.168.1.1

Trying 192.168.1.1, 23 ...

User Access Verification

Password:

！ Prompt for Telnet password, enter Ruijie routera>en here

Password:

！ Prompt for privileged mode password, enter star here

Routera#en

！ Telnet to router A for configuration

routera#

Routera#conf T

Enter configuration commands, one per line. End with cntl/z.

RouterA (config) #exit

routera#

routera#

Routera#exit

！ Use the exit command to exit Telnet login

The above steps can be operated from another machine, the figure is as follows: 650) this.width=650; "Src=" http://s3.51cto.com/wyfs02/M02/87/59/ Wkiol1feki7coyfoaacxvzgqqaa363.jpg-wh_500x0-wm_3-wmp_4-s_3146191415.jpg "title=" ping (1). JPG "alt=" Wkiol1feki7coyfoaacxvzgqqaa363.jpg-wh_50 "/>

Enter the login telnet password, then enter the password into the privileged mode:

650) this.width=650; "Src=" Http://s1.51cto.com/wyfs02/M00/87/59/wKioL1feKNKznZOsAAAtxq6W1zU875.jpg-wh_500x0-wm_3 -wmp_4-s_2406494991.jpg "title=" Capture (1). jpg "alt=" wkiol1feknkznzosaaatxq6w1zu875.jpg-wh_50 "/>

"Precautions"

1. If two routers are connected directly through the serial port, the clock frequency (DCE) must be set at one end.

2, if the Telnet password is not configured, the login will prompt "Password required, but none set".

3, if the Enable password is not configured, then telnet to the router can not enter the privileged mode, prompting "Password required, but none set".

Configure Telnet login for router/switch