Dell PowerSwitch S4820T Configuration Guide for the S4820T System 9.112.0P1 - Page 95

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 configured 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 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 Dell(conf-if-Te-2/1)#dot1x guest-vlan 200 Dell(conf-if-Te 2/1))#show config ! interface TenGigabitEthernet 2/1 switchport dot1x guest-vlan 200 no shutdown Dell(conf-if-Te 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. 802.1X 95