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Catalyst 2928 Switch Software Configuration Guide
OL-23389-01
Chapter 9 Configuring IEEE 802.1x Port-Based Authentication
Configuring IEEE 802.1x Authentication
IEEE 802.1x Authentication Configuration Guidelines
These section has configuration guidelines for these features:
•
IEEE 802.1x Authentication, page 9-19
•
VLAN Assignment and Guest VLAN, page 9-20
•
MAC Authentication Bypass, page 9-20
IEEE 802.1x Authentication
These are the IEEE 802.1x authentication configuration guidelines:
•
When IEEE 802.1x authentication is enabled, ports are authenticated before any other Layer 2
feature is enabled.
•
If you try to change the mode of an IEEE 802.1x-enabled port (for example, from access to trunk),
an error message appears, and the port mode is not changed.
•
If the VLAN to which an IEEE 802.1x-enabled port is assigned changes, this change is transparent
and does not affect the switch. For example, this change occurs if a port is assigned to a RADIUS
server-assigned VLAN and is then assigned to a different VLAN after re-authentication.
If the VLAN to which an IEEE 802.1x port is assigned to shut down, disabled, or removed, the port
becomes unauthorized. For example, the port is unauthorized after the access VLAN to which a port
is assigned shuts down or is removed.
•
The IEEE 802.1x protocol is supported on Layer 2 static-access ports and voice VLAN ports, but it
is not supported on these port types:
–
Trunk port—If you try to enable IEEE 802.1x authentication on a trunk port, an error message
appears, and IEEE 802.1x authentication is not enabled. If you try to change the mode of an
IEEE 802.1x-enabled port to trunk, an error message appears, and the port mode is not changed.
–
Dynamic ports—A port in dynamic mode can negotiate with its neighbor to become a trunk
port. If you try to enable IEEE 802.1x authentication on a dynamic port, an error message
appears, and IEEE 802.1x authentication is not enabled. If you try to change the mode of an
IEEE 802.1x-enabled port to dynamic, an error message appears, and the port mode is not
changed.
–
Dynamic-access ports—If you try to enable IEEE 802.1x authentication on a dynamic-access
(VLAN Query Protocol [VQP]) port, an error message appears, and IEEE 802.1x authentication
is not enabled. If you try to change an IEEE 802.1x-enabled port to dynamic VLAN assignment,
an error message appears, and the VLAN configuration is not changed.
–
EtherChannel port—Do not configure a port that is an active or a not-yet-active member of an
EtherChannel as an IEEE 802.1x port. If you try to enable IEEE 802.1x authentication on an
EtherChannel port, an error message appears, and IEEE 802.1x authentication is not enabled.
–
Switched Port Analyzer (SPAN) destination ports—You can enable IEEE 802.1x authentication
on a port that is a SPAN destination port. However, IEEE 802.1x authentication is disabled until
the port is removed as a SPAN destination port. You can enable IEEE 802.1x authentication on
a SPAN source port.
•
Before globally enabling IEEE 802.1x authentication on a switch by entering the
dot1x
system-auth-control
global configuration command, remove the EtherChannel configuration from
the interfaces on which IEEE 802.1x authentication and EtherChannel are configured.
