A: In Figure1, users want to configure and manage devices easily. To meet this requirement, AAA authentication can be configured on the server for Telnet users, and a security policy can be configured to ensure that only the users matching the security policy can log in to the devices.
Figure1 Configuring Telnet login

Procedure
Step1: Set the server port number and enable the server function.
<HUAWEI> system-view [HUAWEI] sysname Telnet Server [*HUAWEI] commit [Telnet Server] undo telnet server disable [*Telnet Server] telnet server port 1025
# Set the maximum number of VTY user interfaces.
[*Telnet Server] user-interface maximum-vty 8
[*Telnet Server] commit
# Specify the IP address of the host allowed to log in to the device.
[~Telnet Server] acl 2001
[*Telnet Server-acl4-basic-2001] rule permit source 10.137.217.10 32
[*Telnet Server-acl4-basic-2001] rule deny source 10.137.217.20 32
[*Telnet Server-acl4-basic-2001] quit
[*Telnet Server] user-interface vty 0 7
[*Telnet Server-ui-vty0-7] acl 2001 inbound
# Set an authentication mode for the VTY user interface.
[*Telnet Server-ui-vty0-7] authentication-mode aaa
[*Telnet Server-ui-vty0-7] quit
# Set an authentication mode for login users.
Step4: Log in to the client.
[*Telnet Server] aaa
[*Telnet Server-aaa] local-user admin1234 password irreversible-cipher Helloworld@6789
[*Telnet Server-aaa] local-user admin1234 service-type telnet
[*Telnet Server-aaa] local-user admin1234 level 3
[*Telnet Server-aaa] commit
[Telnet Server-aaa] quit
Step4: Log in to the client.
Run the following command at the Windows command line prompt of PC1 to log in to the device using Telnet.
C:\Documents and Settings\Administrator> telnet 10.137.217.177 1025
Press Enter, and input the configured user name and password in the login window. If authentication succeeds, the command line prompt of the user view is displayed, indicating that you have successfully logged in to the device.
Username:admin1234 Password: Info: The max number of VTY users is 8, the number of current VTY users online is 1, and total number of terminal users online is 1. The current login time is 2012-08-04 11:49. First login successfully. <Telnet Server>
You can also find the answer in Common Login Operations in Common Operation Guide.