16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series
Configuration Tasks
61
Cisco IOS Release 12.2(2)XT, 12.2(8)T, and 12.2(15)ZJ
802.1x Configuration Guidelines
These are the 802.1x authentication configuration guidelines:
•
When the 802.1x protocol is enabled, ports are authenticated before any other Layer 2 feature is
enabled.
•
The 802.1x protocol is supported on Layer 2 static-access 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.
–
EtherChannel port—Before enabling 802.1x on the port, you must first remove the port from
the EtherChannel before enabling 802.1x on it. 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.
–
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.
Enabling 802.1x Authentication
To enable 802.1x port-based authentication, you must enable AAA and specify the authentication
method list. A method list describes the sequence and authentication methods to be queried to
authenticate a user.
The software uses the first method listed to authenticate users; if that method fails to respond, the
software selects the next authentication method in the method list. This process continues until there is
successful communication with a listed authentication method or until all defined methods are
exhausted. If authentication fails at any point in this cycle, the authentication process stops, and no other
authentication methods are attempted.
Beginning in privileged EXEC mode, follow these steps to configure 802.1x port-based authentication.
This procedure is required.
Command
Purpose
Step 1
configure terminal
Enters global configuration mode.
Step 2
aaa new-model
Enables AAA.
Step 3
aaa authentication dot1x {default |
listname} method1 [method2...]
Creates an 802.1x authentication method list.
To create a default list that is used when a named list is not specified in
the authentication command, use the default keyword followed by the
methods that are to be used in default situations. The default method list
is automatically applied to all interfaces.
Enter at least one of these keywords:
•
group radius—Use the list of all RADIUS servers for authentication.
•
none—Use no authentication. The client is automatically
authenticated without the switch using the information supplied by
the client.
