The invention enables a client device that does not support IEEE 802.1X authentication to access at least some resources provided through a switch that supports 802.1X authentication by using dynamic authentication with different protocols. When the client device attempts to join a network, the switch monitors for an 802.1X authentication message from the client device. In one embodiment, if the client fails to send an 802.1X authentication message, respond to an 802.1X request from the switch, or a predefined failure condition is detected the client may be deemed incapable of supporting 802.1X authentication. In one embodiment, the client may be initially placed on a quarantine VLAN after determination that the client fails to perform an 802.1X authentication within a backoff time limit. However, the client may still gain access to resources based on various non-802.1X authentication mechanisms, including name/passwords, digital certificates, or the like.