Reference Guide

Denying and Permitting Access to a Terminal Line
Dell Networking recommends applying only standard access control lists (ACLs) to deny and permit access to VTY lines.
● Layer 3 ACLs deny all traffic that is not explicitly permitted, but in the case of VTY lines, an ACL with no rules does not deny
traffic.
● You cannot use the show ip accounting access-list command to display the contents of an ACL that is applied
only to a VTY line.
To apply an IP ACL to a line, Use the following command.
● Apply an ACL to a VTY line.
LINE mode
ip access-class access-list
To view the configuration, use the show config command in LINE mode.
Dell(config-std-nacl)#show config
!
ip access-list standard myvtyacl
seq 5 permit host 10.11.0.1
Dell(config-std-nacl)#line vty 0
Dell(config-line-vty)#show config
line vty 0
access-class myvtyacl
Configuring Login Authentication for Terminal Lines
You can use any combination of up to six authentication methods to authenticate a user on a terminal line.
A combination of authentication methods is called a method list. If the user fails the first authentication method, the system
prompts the next method until all methods are exhausted, at which point the connection is terminated. The available
authentication methods are:
enable
Prompt for the enable password.
line
Prompt for the password you assigned to the terminal line. Configure a password for the terminal line to
which you assign a method list that contains the line authentication method. Configure a password using
the password command from LINE mode.
local
Prompt for the system username and password.
none
Do not authenticate the user.
radius
Prompt for a username and password and use a RADIUS server to authenticate.
tacacs+
Prompt for a username and password and use a TACACS+ server to authenticate.
1. Configure an authentication method list. You may use a mnemonic name or use the keyword default. The default
authentication method for terminal lines is local and the default method list is empty.
CONFIGURATION mode
aaa authentication login {method-list-name | default} [method-1] [method-2] [method-3]
[method-4] [method-5] [method-6]
2. Apply the method list from Step 1 to a terminal line.
CONFIGURATION mode
login authentication {method-list-name | default}
3. If you used the line authentication method in the method list you applied to the terminal line, configure a password for the
terminal line.
LINE mode
password
In the following example, VTY lines 0-2 use a single authentication method, line.
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