Configuring Port-Based and User-Based Access Control (802.1X)

802.1X Open VLAN Mode

Condition

Rule

 

 

Note: Limitation on Using an Unauthorized-Client VLAN on an 802.1X Port Configured to Allow Multiple-Client Access

You can optionally enable switches to allow up to 32 clients per-port. The Unauthorized-Client VLAN feature can operate on an 802.1X- configured port regardless of how many clients the port is configured to support. However, all clients on the same port must operate through the same untagged VLAN membership. This means that any client accessing a given port must be able to authenticate and operate on the same VLAN as any other previously authenticated clients that are currently using the port. Thus, an Unauthorized-Client VLAN configured on a switch port that allows multiple 802.1X clients cannot be used if there is already an authenticated client using the port on another VLAN. Also, a client using the Unauthenticated-Client VLAN will be blocked when another client becomes authenticated on the port. For this reason, the best utilization of the Unauthorized-Client VLAN feature is in instances where only one client is allowed per-port. Otherwise, unauthenticated clients are subject to being blocked at any time by authenticated clients using a different VLAN. (Using the same VLAN for authenticated and unauthenticated clients can create a security risk and is not recommended.)

N o t e

If you use the same VLAN as the Unauthorized-Client VLAN for all authenti-

 

cator ports, unauthenticated clients on different ports can communicate with

 

each other.

 

 

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