Users Guide

5 Verify that the port has been authorized and placed in the desired VLAN (refer to the illustration in Dynamic VLAN Assignment with
Port Authentication).
Guest and Authentication-Fail VLANs
Typically, the authenticator (the Dell system) denies the supplicant access to the network until the supplicant is authenticated. If the
supplicant is authenticated, the authenticator enables the port and places it in either the VLAN for which the port is congured or the
VLAN that the authentication server indicates in the authentication data.
NOTE: Ports cannot be dynamically assigned to the default VLAN.
If the supplicant fails authentication, the authenticator typically does not enable the port. In some cases this behavior is not appropriate.
External users of an enterprise network, for example, might not be able to be authenticated, but still need access to the network. Also,
some dumb-terminals, such as network printers, do not have 802.1X capability and therefore cannot authenticate themselves. To be able to
connect such devices, they must be allowed access the network without compromising network security.
The Guest VLAN 802.1X extension addresses this limitation with regard to non-802.1X capable devices and the Authentication-fail VLAN
802.1X extension addresses this limitation with regard to external users.
• If the supplicant fails authentication a specied number of times, the authenticator places the port in the Authentication-fail VLAN.
• If a port is already forwarding on the Guest VLAN when 802.1X is enabled, the port is moved out of the Guest VLAN and the
authentication process begins.
Conguring a Guest VLAN
If the supplicant does not respond within a determined amount of time ([reauth-max + 1] * tx-period, the system assumes that the host
does not have 802.1X capability and the port is placed in the Guest VLAN.
NOTE
: For more information about conguring timeouts, refer to Conguring Timeouts.
Congure a port to be placed in the Guest VLAN after failing to respond within the timeout period using the dot1x guest-vlan
command from INTERFACE mode. View your conguration using the show config command from INTERFACE mode or using the show
dot1x interface
command from EXEC Privilege mode.
Example of Viewing Guest VLAN Conguration
DellEMC(conf-if-Te-2/1)#dot1x guest-vlan 200
DellEMC(conf-if-Te 2/1))#show config
!
interface TenGigabitEthernet 2/1
switchport
dot1x guest-vlan 200
no shutdown
DellEMC(conf-if-Te 2/1))#
Conguring an Authentication-Fail VLAN
If the supplicant fails authentication, the authenticator re-attempts to authenticate after a specied amount of time.
NOTE
: For more information about authenticator re-attempts, refer to Conguring a Quiet Period after a Failed Authentication.
You can congure the maximum number of times the authenticator re-attempts authentication after a failure (3 by default), after which the
port is placed in the Authentication-fail VLAN.
Congure a port to be placed in the VLAN after failing the authentication process as specied number of times using the dot1x auth-
fail-vlan
command from INTERFACE mode. Congure the maximum number of authentication attempts by the authenticator using
the keyword max-attempts with this command.
104
802.1X