Cisco IOS Basic CLI Configuration：Access Security 01

1. Telnet

Switch Config：

Switch>en

Switch#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Switch(config)#enable secret zhang

Switch(config)#line console 0

Switch(config-line)#password 123

Switch(config-line)#login

Switch(config-line)#exit

Switch(config)#line vty 0 15

Switch(config-line)#password hello

Switch(config-line)#login

Switch(config-line)#exit

Switch(config)#interface vlan 1

Switch(config-if)#ip address 192.168.1.1 255.255.255.0

Switch(config-if)#no shutdown

Switch(config-if)#

%LINK-5-CHANGED: Interface Vlan1, changed state to up

Switch(config-if)#exit

Switch(config)#exit

Switch#

Switch#show running-config

Building configuration...

Current configuration : 1152 bytes

!

hostname Switch

!

enable secret 5 $1$mERr$Ihkqz6Aphv2yflqGpdU2m0

!

interface Vlan1

ip address 192.168.1.1 255.255.255.0

!

line con 0

password 123

login

!

line vty 0 4

password hello

login

line vty 5 15

password hello

login

!

!

end

Switch#

PC1 Telnet Test：

2. SSH

Switch#conf t

Enter configuration commands, one per line. End with CNTL/Z.

Switch(config)#line vty 0 15

Switch(config-line)#login local

Switch(config-line)#exit

Switch(config)#username user1 password 123

Switch(config)#username user2 password 123

Switch(config)#ip domain-name example.com

Switch(config)#crypto key generate rsa

% Please define a hostname other than Switch.

Switch(config)#hostname zhang

zhang(config)#crypto key generate rsa

The name for the keys will be: zhang.example.com

Choose the size of the key modulus in the range of 360 to 2048 for your

General Purpose Keys. Choosing a key modulus greater than 512 may take

a few minutes.

How many bits in the modulus [512]: 1024

% Generating 1024 bit RSA keys, keys will be non-exportable...[OK]

zhang(config)#ip ssh version 2

*?? 1 0:30:20.486: %SSH-5-ENABLED: SSH 1.99 has been enabled

zhang(config)#

zhang(config)#

3. Encrypting Password

conf t

service password-encryption

4. Support Telnet SSH on vty line

transport input all or transport input telnet ssh : support both

transport input none: Support neither

transport input telnet: Support only Telnet

transport input ssh: Support only SSH