Dell Force10 S55T S55 Configuration Guide FTOS 8.3.5.3 - Page 97

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, then 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, see Configuring Timeouts on page 94) the system assumes that the host does not have 802.1X capability, and and the port is placed in the Guest VLAN. Configure a port to be placed in the Guest VLAN after failing to respond within the timeout period using the command dot1x guest-vlan from INTERFACE mode, as shown in Figure 6-12. Figure 6-12. Configuring a Guest VLAN Force10(conf-if-gi-1/2)#dot1x guest-vlan 200 Force10(conf-if-gi-1/2)#show config ! interface GigabitEthernet 1/2 switchport dot1x guest-vlan 200 no shutdown Force10(conf-if-gi-1/2)# View your configuration using the command show config from INTERFACE mode, as shown in Figure 6-12, or using the command show dot1x interface command from EXEC Privilege mode as shown in Figure 6-14. Configuring an Authentication-fail VLAN If the supplicant fails authentication, the authenticator re-attempts to authenticate after a specified amount of time (30 seconds by default, see Configuring a Quiet Period after a Failed Authentication on page 90). 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 command dot1x auth-fail-vlan from INTERFACE mode, as shown in Figure 6-13. Configure the maximum number of authentication attempts by the authenticator using the keyword max-attempts with this command. 802.1X | 97