Administrator Guide

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 specified 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.
Configuring 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 configuring timeouts, refer to Configuring Timeouts.
Configure 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 configuration using the show config command from INTERFACE mode or using the
show dot1x interface command from EXEC Privilege mode.
Example of Viewing Guest VLAN Configuration
DellEMC(conf-if-gi-2/1)#dot1x guest-vlan 200
DellEMC(conf-if-gi 2/1))#show config
!
interface GigabitEthernet 2/1
switchport
dot1x guest-vlan 200
no shutdown
DellEMC(conf-if-gi 2/1))#
Configuring an Authentication-Fail VLAN
If the supplicant fails authentication, the authenticator re-attempts to authenticate after a specified amount of time.
NOTE:
For more information about authenticator re-attempts, refer to Configuring a Quiet Period after a Failed
Authentication.
You can configure 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.
Configure a port to be placed in the VLAN after failing the authentication process as specified number of times using the dot1x auth-
fail-vlan command from INTERFACE mode. Configure the maximum number of authentication attempts by the authenticator using
the keyword max-attempts with this command.
Example of Configuring Maximum Authentication Attempts
DellEMC(conf-if-gi-2/1)#dot1x guest-vlan 200
DellEMC(conf-if-gi 2/1)#show config
!
interface GigabitEthernet 2/1
switchport
dot1x authentication
dot1x guest-vlan 200
no shutdown
DellEMC(conf-if-gi-2/1)#
DellEMC(conf-if-gi-2/1)#dot1x auth-fail-vlan 100 max-attempts 5
DellEMC(conf-if-gi-2/1)#show config
!
interface GigabitEthernet 2/1
switchport
dot1x authentication
dot1x guest-vlan 200
dot1x auth-fail-vlan 100 max-attempts 5
802.1X
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