Default 802.1X Configuration

Enabling 802.1X Authentication
Step 1 configure terminal
 Enter global configuration mode.
Step 2 aaa new-model Enable AAA.

Step 3 aaa authentication dot1x {default}
method1 [method2...]
Create an 802.1X authentication method list.
To create a default list that is used when a named list is not specified in
the authentication command, use the default keyword followed by the
methods that are to be used in default situations. The default method list
is automatically applied to all interfaces.
Enter at least one of these keywords:
• group radius—Use the list of all RADIUS servers for authentication.
• none—Use no authentication. The client is automatically
authenticated without the switch using the information supplied by
the client.

Step 4 interface interface-id
 Enter interface configuration mode, and specify the interface to be
enabled for 802.1X authentication.

Step 5 dot1x port-control auto Enable 802.1X authentication on the interface.
For feature interaction information with trunk, dynamic, dynamic-access,
EtherChannel, secure, and SPAN ports see the “802.1X Configuration
Guidelines” section on page 8-7.

Step 6 end Return to privileged EXEC mode.

Step 7 show dot1x Verify your entries.
Check the Status column in the 802.1X Port Summary section of the
display. An enabled status means the port-control value is set either to
auto or to force-unauthorized.

Step 8 copy running-config startup-config (Optional) Save your entries in the configuration file.
eg:
Switch# configure terminal
Switch(config)# aaa new-model
Switch(config)# aaa authentication dot1x default group radius
Switch(config)# interface fastethernet0/1
Switch(config-if)# dot1x port-control auto
Switch(config-if)# end

Configuring the Switch-to-RADIUS-Server Communication

Step 1 configure terminal Enter global configuration mode.
Step 2 radius-server host {hostname |
ip-address} auth-port port-number key
string
Configure the RADIUS server parameters on the switch.
For hostname | ip-address, specify the host name or IP address of the
remote RADIUS server.
For auth-port port-number, specify the UDP destination port for
authentication requests. The default is 1812.
For key string, specify the authentication and encryption key used
between the switch and the RADIUS daemon running on the RADIUS
server. The key is a text string that must match the encryption key used on
the RADIUS server.
Note Always configure the key as the last item in the radius-server
host command syntax because leading spaces are ignored, but
spaces within and at the end of the key are used. If you use spaces
in the key, do not enclose the key in quotation marks unless the
quotation marks are part of the key. This key must match the
encryption used on the RADIUS daemon.
If you want to use multiple RADIUS servers, re-enter this command.
Step 3 end Return to privileged EXEC mode.
Step 4 show running-config Verify your entries.
Step 5 copy running-config startup-config (Optional) Save your entries in the configuration file.

To delete the specified RADIUS server, use the no radius-server host {hostname | ip-address} global
configuration command.
This example shows how to specify the server with IP address 172.20.39.46 as the RADIUS server, to
use port 1612 as the authorization port, and to set the encryption key to rad123, matching the key on the
RADIUS server:
Switch(config)# radius-server host 172.l20.39.46 auth-port 1612 key rad123
You can globally configure the timeout, retransmission, and encryption key values for all RADIUS
servers by using the radius-server host global configuration command. If you want to configure these
options on a per-server basis, use the radius-server timeout, radius-server retransmit, and the
radius-server key global configuration commands.

Enabling Periodic Re-Authentication
Step 1 configure terminal Enter global configuration mode.
Step 2 dot1x re-authentication Enable periodic re-authentication of the client, which is disabled by
default.
Step 3 dot1x timeout re-authperiod seconds Set the number of seconds between re-authentication attempts.
The range is 1 to 4294967295; the default is 3600 seconds.
This command affects the behavior of the switch only if periodic
re-authentication is enabled.
Step 4 end Return to privileged EXEC mode.
Step 5 show dot1x Verify your entries.
Step 6 copy running-config startup-config (Optional) Save your entries in the configuration file.

Switch(config)# dot1x re-authentication
Switch(config)# dot1x timeout re-authperiod 4000

Manually Re-Authenticating a Client Connected to a Port
You can manually re-authenticate the client connected to a specific port at any time by entering the
dot1x re-authenticate interface interface-id privileged EXEC command. If you want to enable or
disable periodic re-authentication
Switch# dot1x re-authenticate interface fastethernet0/1
Starting reauthentication on FastEthernet0/1