Dell POWEREDGE M1000E - Manual (Page 280)

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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
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Chapter 10 Configuring IEEE 802.1x Port-Based Authentication
Understanding IEEE 802.1x Port-Based Authentication
Cisco Secure ACS and Attribute-Value Pairs for Downloadable ACLs
You can set the CiscoSecure-Defined-ACL Attribute-Value (AV) pair on the Cisco Secure ACS with the
RADIUS cisco-av-pair vendor-specific attributes (VSAs). This pair specifies the names of the
downloadable ACLs on the Cisco Secure ACS with the #ACL#-IP-name-number attribute.
• The name is the ACL name.
• The number is the version number (for example, 3f783768).
If a downloadable ACL is configured for a client on the authentication server, a default port ACL on the
connected client switch port must also be configured.
If the default ACL is configured on the switch and the Cisco Secure ACS sends a host-access-policy to
the switch, it applies the policy to traffic from the host connected to a switch port. If the policy does not
apply, the switch applies the default ACL. If the Cisco Secure ACS sends the switch a downloadable
ACL, this ACL takes precedence over the default ACL that is configured on the switch port. However,
if the switch receives an host access policy from the Cisco Secure ACS but the default ACL is not
configured, the authorization failure is declared.
For configuration details, see the “ “Authentication Manager” section on page 10-7 and the “Configuring
802.1x Authentication with Downloadable ACLs and Redirect URLs” section on page 10-57 .
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 services to
clients, such as downloading the IEEE 802.1x client. These clients might be upgrading their system for
IEEE 802.1x authentication, and some hosts, such as Windows 98 systems, might not 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 packet is detected on the interface during
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 does not change to the guest VLAN state. EAPOL
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-capable voice device and the AAA server 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 devices access 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.