Using Ieee 802.1X Authentication With Vlan Assignment - Cisco IE 3000 Software Configuration Manual

Understanding IEEE 802.1x Port-Based Authentication

Using IEEE 802.1x Authentication with VLAN Assignment

The RADIUS server sends the VLAN assignment to configure the switch port. The RADIUS server
database maintains the username-to-VLAN mappings, assigning the VLAN based on the username of
the client connected to the switch port. You can use this feature to limit network access for certain users.
Voice device authentication is supported with multidomain host mode. When a voice device is authorized
and the RADIUS server returned an authorized VLAN, the voice VLAN on the port is configured to send
and receive packets on the assigned voice VLAN.
When configured on the switch and the RADIUS server, IEEE 802.1x authentication with VLAN
assignment has these characteristics:
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When the port is in the force authorized, force unauthorized, unauthorized, or shutdown state, it is put
into the configured access VLAN.
The IEEE 802.1x authentication with VLAN assignment feature is not supported on trunk ports, dynamic
ports, or with dynamic-access port assignment through a VLAN Membership Policy Server (VMPS).
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If no VLAN is supplied by the RADIUS server or if IEEE 802.1x authentication is disabled, the port
is configured in its access VLAN after successful authentication. Recall that an access VLAN is a
VLAN assigned to an access port. All packets sent from or received on this port belong to this
VLAN.
If IEEE 802.1x authentication is enabled but the VLAN information from the RADIUS server is not
valid, authorization fails and configured VLAN remains in use. This prevents ports from appearing
unexpectedly in an inappropriate VLAN because of a configuration error.
Configuration errors could include specifying a malformed VLAN ID, a nonexistent VLAN ID, an
RSPAN VLAN, a shut down or suspended VLAN. In the case of a mutlidomain host port,
configuration errors can also be due to an attempted assignment of a data VLAN that matches the
configured or assigned voice VLAN ID (or the reverse).
If IEEE 802.1x authentication is enabled and all information from the RADIUS server is valid, the
authorized device is placed in the specified VLAN after authentication.
If the multiple-hosts mode is enabled on an IEEE 802.1x port, all hosts are placed in the same VLAN
(specified by the RADIUS server) as the first authenticated host.
Enabling port security does not impact the RADIUS server-assigned VLAN behavior.
If IEEE 802.1x authentication is disabled on the port, it is returned to the configured access VLAN
and configured voice VLAN.
If an IEEE 802.1x port is authenticated and put in the RADIUS server-assigned VLAN, any change
to the port access VLAN configuration does not take effect. In the case of a multidomain host, the
same applies to voice devices when the port is fully authorized with these exceptions:
If the VLAN configuration change of one device results in matching the other device configured
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or assigned VLAN, then authorization of all devices on the port is terminated and multidomain
host mode is disabled until a valid configuration is restored where data and voice device
configured VLANs no longer match.
– If a voice device is authorized and is using a downloaded voice VLAN, the removal of the voice
VLAN configuration, or modifying the configuration value to dot1p or untagged results in voice
device un-authorization and the disablement of multi-domain host mode.
Chapter 10 Configuring IEEE 802.1x Port-Based Authentication
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