Configuring A Guest Vlan - Cisco Catalyst 2950 Software Configuration Manual

Chapter 9 Configuring IEEE 802.1x Port-Based Authentication

Configuring a Guest VLAN

When you configure a guest VLAN, clients that are not IEEE 802.1x-capable are put into the guest
VLAN when the server does not receive a response to its EAPOL request/identity frame. Clients that are
IEEE 802.1x-capable but fail authentication are not granted access to the network. The switch supports
guest VLANs in single-host or multiple-hosts mode.
Beginning in privileged EXEC mode, follow these steps to configure a guest VLAN. This procedure is
optional.
Command
Step 1
configure terminal
Step 2 interface interface-id
Step 3 switchport mode access
Step 4 dot1x port-control auto
Step 5
dot1x guest-vlan vlan-id
Step 6
end
Step 7 show dot1x interface interface-id
Step 8 copy running-config startup-config
To disable and remove the guest VLAN, use the no dot1x guest-vlan interface configuration command.
The port returns to the unauthorized state.
This example shows how to enable VLAN 9 as an IEEE 802.1x guest VLAN on a port:
Switch(config)# interface fastethernet0/1
Switch(config-if)# dot1x guest-vlan 9
This example shows how to set 3 as the quiet time on the switch, to set 15 as the number of seconds that
the switch waits for a response to an EAP-request/identity frame from the client before resending the
request, and to enable VLAN 2 as an IEEE 802.1x guest VLAN when an IEEE 802.1x port is connected
to a DHCP client:
Switch(config-if)# dot1x timeout quiet-period 3
Switch(config-if)# dot1x timeout tx-period 15
Switch(config-if)# dot1x guest-vlan 2
You can enable optional guest VLAN behavior by using the dot1x guest-vlan supplicant global
configuration command. When enabled, the switch does not maintain the EAPOL packet history and
allows clients that fail authentication access to the guest VLAN, regardless of whether EAPOL packets
had been detected on the interface.
78-11380-12
Purpose
Enter global configuration mode.
Specify the interface to be configured, and enter interface configuration
mode. For the supported interface types, see the
Configuration Guidelines" section on page
Set the port to access mode.
Enable IEEE 802.1x authentication on the port.
Specify an active VLAN as an IEEE 802.1x guest VLAN. The range is 1
to 4094.
You can configure any active VLAN except an RSPAN VLAN or a voice
VLAN as an IEEE 802.1x guest VLAN.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entries in the configuration file.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
Configuring IEEE 802.1x Authentication
"IEEE 802.1x
9-12.
9-21