telnet configuration experiment
1. Overview
Telnet is used in remote login to manage and configure one-to-many devices. Greatly improve the flexibility of user maintenance operations
2. Experimental topology:
3. Summary of the experiment: The
same segment of the network is connected by a switch for the convenience of user management. r2 can remotely telnet, and
password authentication is required to improve security . Only network administrators can manage device configuration. Ordinary users can only monitor.
Device interface Ip mask gateway
R1 G0/0/0 10.1.1.254 24 N/a
R2 G0/0/0 10.1.1.1 24 10.1.1.254
R3 G0/0/0 10.1.1.2 24 10.1.1.254
4. Experimental step
A. Basic configuration
B. Telnet password authentication:
Configure the telnet function. set password. The configuration file is displayed in an encrypted manner.
R1:
Sys
Sysname r1
User-interface vty 0 4
Authentication-mode password Huawei
Protocol inbound telnet
//允许被telnet
Display users view logged in
C. Differentiate user permissions The default vty user level is 0 visitor level, and you cannot enter the system view
R1: user-intface vty 0 4
User privilege level 1
D. Use user name and password alone to manage user level 3
R1: aaa
Local-user admin password cipher hello privilege level 3 // 用户名用户级别
Local-user admin service-type telnet
User-intface vty 0 4
Authentication-mode aaa
User level 3 can configure and manage remote routers.
Thinking: Is telnet based on tcp or udp? why
Tcp, telnet are one-to-one traffic, the traffic generated by tcp can only be sent unicast
Is the telnet application safe? why?
Insecure, no password protection, no strong authentication, no encryption.
display users view the information of logged-in users