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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
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Chapter9 Configuring IEEE 802 . 1x Port-Based Authentication Understanding IEEE 802.1x Port-Based Authentication
For examples of vendor-specific attributes, see the “Configuring the Switch to Use Vendor-Specific
RADIUS Attributes” section on page 7-29. For more information about configuring ACLs, see
Chapter 34, “Configuring Network Security with ACLs.”
To configure per-user ACLs, you need to perform these tasks:
•Enable AAA authentication.
•Enable AAA authorization by using the network keyword to allow interface configuration from the
RADIUS server.
•Enable IEEE 802.1x authentication.
•Configure the user profile and VSAs on the RADIUS server.
•Configure the IEEE 802.1x port for single-host mode.
Using IEEE 802.1x Authentication with Guest VLAN
You can configure a guest VLAN for each IEEE 802.1x port on the switch to provide limited servic es to
clients, such as downloading the IEEE 802.1x client. These clients migh t be upgrading their system for
IEEE 802.1x authentication, and some hosts, such as Windows 98 systems, might no t be
IEEE 802.1x-capable.
When you enable a guest VLAN on an IEEE 802.1x port, the switch assigns clients to a guest VLAN
when the switch does not receive a response to its EAP request/identity frame or when EAPOL packets
are not sent by the client.
The switch maintains the EAPOL packet history. If an EAPOL pack et is detecte d on the interf ace du ring
the lifetime of the link, the switch determines that the device connected to that interface is an
IEEE 802.1x-capable supplicant, and the interface doe s n ot c ha nge to t he gu est VLA N s ta te. EA PO L
history is cleared if the interface link status goes down. If no EAPOL packet is detected on the interface,
the interface changes to the guest VLAN state.
If the switch is trying to authorize an IEEE 802.1x-ca pa ble voice device and the AA A se r ver is
unavailable, the authorization attempt fails, but the detection of the EAPOL packet is saved in the
EAPOL history. When the AAA server becomes available, the switch authorizes the voice device.
However, the switch no longer allows other de vices acc ess to the guest VLAN. To prevent this situation,
use one of these command sequences:
•Enter the dot1x guest-vlan supplicant global configuration command to allow access to the guest
VLAN.
•Enter the shutdown interface configuration command followed by the no shutdown interface
configuration command to restart the port.
Use a restricted VLAN to allow clients that failed authentication access to the network by entering the
dot1x auth-fail vlan vlan-id interface configuration command.
If devices send EAPOL packets to the switch during the lifetime of the link, the switch no longer allows
clients that fail authentication access to the guest VLAN.
Note If an EAPOL packet is detected after the interface has changed to the guest VLAN, the interface reverts
to an unauthorized state, and IEEE 802.1x authentication rest ar ts.