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Cisco IE 3010 Switch Software Configuration Guide
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Chapter 10 Configuring IEEE 802.1x Port-Based Authentication
Understanding IEEE 802.1x Port-Based Authentication
The switch supports multidomain authentication (MDA), which allows both a data device and a voice
device, such as an IP Phone (Cisco or non-Cisco), to connect to the same switch port. For more
information, see the “Multidomain Authentication” section on page 10-12.
Multidomain Authentication
The switch supports multidomain authentication (MDA), which allows both a data device and voice
device, such as an IP phone (Cisco or non-Cisco), to authenticate on the same switch port. The port is
divided into a data domain and a voice domain.
MDA does not enforce the order of device authentication. However, for best results, we recommend that
a voice device is authenticated before a data device on an MDA-enabled port.
Follow these guidelines for configuring MDA:
• To configure a switch port for MDA, see the “Configuring the Host Mode” section on page 10-43.
• You must configure the voice VLAN for the IP phone when the host mode is set to multidomain.
For more information, see Chapter 14, “Configuring VLANs.”
• To authorize a voice device, the AAA server must be configured to send a Cisco Attribute-Value
(AV) pair attribute with a value of device-traffic-class=voice. Without this value, the switch
treats the voice device as a data device.
• The guest VLAN and restricted VLAN features only apply to the data devices on an MDA-enabled
port. The switch treats a voice device that fails authorization as a data device.
• If more than one device attempts authorization on either the voice or the data domain of a port, it is
error disabled.
• Until a device is authorized, the port drops its traffic. Non-Cisco IP phones or voice devices are
allowed into both the data and voice VLANs. The data VLAN allows the voice device to contact a
DHCP server to obtain an IP address and acquire the voice VLAN information. After the voice
device starts sending on the voice VLAN, its access to the data VLAN i s blocked.
• A voice device MAC address that is binding on the data VLAN is not counted t owards the port
security MAC address limit.
• MDA can use MAC authentication bypass as a fallback mechanism to allow the switch port to
connect to devices that do not support 802.1x authentication. For more information, see the “MAC
Authentication Bypass” section on page 10-37.
• When a data or a voice device is detected on a port, its MAC address is blocked until authorization
succeeds. If the authorization fails, the MAC address remains blocked for 5 minutes.
• If more than five devices are detected on the data VLAN or more than one voice device is detected
on the voice VLAN while a port is unauthorized, the port is error disabled.
• When a port host mode changes from single- or multihost to multidomain mode, an authorized data
device remains authorized on the port. However, a Cisco IP phone on the port voice VLAN is
automatically removed and must be reauthenticated on that port.
• Active fallback mechanisms such as guest VLAN and restricted VLAN remain configured after a
port changes from single-host or multiple-host mode to multidom ain mode.
• Switching a port host mode from multidomain to single-host or multiple-hosts mode removes all
authorized devices from the port.
• If a data domain is authorized first and placed in the guest VLAN, non-802.1x-capable voice devices
need their packets tagged on the voice VLAN to trigger authentication. The phone need not need to
send tagged traffic. (The same is true for an 802.1x-capable phone.)