802.1X Configuration Guidelines - Cisco WS-C3550-12G Software Configuration Manual

Chapter 7 Configuring 802.1X Port-Based Authentication

802.1X Configuration Guidelines

These are the 802.1X authentication configuration guidelines:
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When 802.1X is enabled, ports are authenticated before any other Layer 2 or Layer 3 features are
enabled.
The 802.1X protocol is supported on both Layer 2 static-access ports and Layer 3 routed ports, but
it is not supported on these port types:
– Trunk port—If you try to enable 802.1X on a trunk port, an error message appears, and 802.1X
is not enabled. If you try to change the mode of an 802.1X-enabled port to trunk, 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 802.1X on a dynamic port, an error message appears, and 802.1X is
not enabled. If you try to change the mode of an 802.1X-enabled port to dynamic, the port mode
is not changed.
Dynamic-access ports—If you try to enable 802.1X on a dynamic-access (VLAN Query
–
Protocol [VQP]) port, an error message appears, and 802.1X is not enabled. If you try to change
an 802.1X-enabled port to dynamic VLAN assignment, an error message appears, and the
VLAN configuration is not changed.
– EtherChannel port—Before enabling 802.1X on the port, you must first remove it from the
EtherChannel. If you try to enable 802.1X on an EtherChannel or on an active port in an
EtherChannel, an error message appears, and 802.1X is not enabled. If you enable 802.1X on a
not-yet active port of an EtherChannel, the port does not join the EtherChannel.
– Secure port—You cannot configure a secure port as an 802.1X port. If you try to enable 802.1X
on a secure port, an error message appears, and 802.1X is not enabled. If you try to change an
802.1X-enabled port to a secure port, an error message appears, and the security settings are not
changed.
Switch Port Analyzer (SPAN) destination port—You can enable 802.1X on a port that is a SPAN
–
destination port; however, 802.1X is disabled until the port is removed as a SPAN destination.
You can enable 802.1X on a SPAN source port.
Catalyst 3550 Multilayer Switch Software Configuration Guide
Configuring 802.1X Authentication
7-7