Experiment One: Configure Telnet login for the router

"Experimental Purpose"

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

"Background description"
When routers are used to connect multiple subnets, the placement is usually far apart, and it is more difficult to see and modify the configuration.
At this point, if you can telnet to the router to operate, you will be able to significantly reduce the workload of administrators.
"Demand Analysis"
Need to know how to configure the password for the router, how to configure the Telnet service, and how to Telnet
The method by which the router operates.

"Experimental Equipment"

Router (with serial port) 2 units

v.35 Dce/dte Cable 1 Pair

"Pre-knowledge"

How routers work and basic configuration methods

"Experimental principle"

Connect two routers via serial port to v.35 DTE/DCE cable, configure Telnet separately to

Log in to each other with a Telnet method.

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). Requirements must be in

The DCE terminal configures the clock rate to ensure link connectivity.

"Experimental Steps"

Step One: Configure the name and interface of the router the 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 2/0

！ 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

R3740#configure Terminal

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

R3740 (config) #hostname Routerb

Routerb (config) #interface serial 4/0

Routerb (config-if) #ip address 192.168.1.2 255.255.255.0

Routerb (config-if) #no shutdown

Routerb (config-if) #exit

Step Two: Configure the second step: 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

Routerb (config) #enable password Ruijie

Routerb (config) #line vty 0 4

Routerb (Config-line) #password star

Routerb (Config-line) #login

Routerb (Config-line) #end

Step three: Test network connectivity in 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 here

routera>en

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

routerb#

Routera#ping 192.168.1.2

Sending 5, 100-byte ICMP echoes to 192.168.1.2, timeout is 2 seconds:

< Press CTRL + C to break >

!!!!!

Success rate is percent (5/5), round-trip Min/avg/max = 1/4/10 ms

Routera#telnet 192.168.1.2

Trying 192.168.1.2, 23 ...

User Access Verification

Password:

routerb>en

Password:

routerb#

Routerb#conf T

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

Routerb (config) #exit

routerb#

Routerb#exit

routera#

"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 remote login to the router can not enter the privileged mode, prompting

"Password required, but none set"

"Experimental Experience"

The experiment gave full play to the hands-on ability to recognize how to configure Telnet on the router

Experiment One: Configure Telnet login for the router