•
Configure the RADIUS server to send more than one VLAN name for a user. The multiple VLAN names
can be sent as part of the response to the user. The 802.1x user distribution tracks all the users in a
particular VLAN and achieves load balancing by moving the authorized user to the least populated
VLAN.
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Configure the RADIUS server to send a VLAN group name for a user. The VLAN group name can be
sent as part of the response to the user. You can search for the selected VLAN group name among the
VLAN group names that you configured by using the switch CLI. If the VLAN group name is found,
the corresponding VLANs under this VLAN group name are searched to find the least populated VLAN.
Load balancing is achieved by moving the corresponding authorized user to that VLAN.
The RADIUS server can send the VLAN information in any combination of VLAN-IDs,
VLAN names, or VLAN groups.
Note
802.1x User Distribution Configuration Guidelines
•
Confirm that at least one VLAN is mapped to the VLAN group.
•
You can map more than one VLAN to a VLAN group.
•
You can modify the VLAN group by adding or deleting a VLAN.
•
When you clear an existing VLAN from the VLAN group name, none of the authenticated ports in the
VLAN are cleared, but the mappings are removed from the existing VLAN group.
•
If you clear the last VLAN from the VLAN group name, the VLAN group is cleared.
•
You can clear a VLAN group even when the active VLANs are mapped to the group. When you clear
a VLAN group, none of the ports or users that are in the authenticated state in any VLAN within the
group are cleared, but the VLAN mappings to the VLAN group are cleared.
IEEE 802.1x Authentication with Voice VLAN Ports
A voice VLAN port is a special access port associated with two VLAN identifiers:
•
VVID to carry voice traffic to and from the IP phone. The VVID is used to configure the IP phone
connected to the port.
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PVID to carry the data traffic to and from the workstation connected to the switch through the IP phone.
The PVID is the native VLAN of the port.
The IP phone uses the VVID for its voice traffic, regardless of the authorization state of the port. This allows
the phone to work independently of IEEE 802.1x authentication.
In single-host mode, only the IP phone is allowed on the voice VLAN. In multiple-hosts mode, additional
clients can send traffic on the voice VLAN after a supplicant is authenticated on the PVID. When multiple-hosts
mode is enabled, the supplicant authentication affects both the PVID and the VVID.
A voice VLAN port becomes active when there is a link, and the device MAC address appears after the first
CDP message from the IP phone. Cisco IP phones do not relay CDP messages from other devices. As a result,
if several IP phones are connected in series, the switch recognizes only the one directly connected to it. When
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Configuring IEEE 802.1x Port-Based Authentication
IEEE 802.1x Authentication with Voice VLAN Ports