Troubleshooting

Unusual Network Activity

�Use ping to ensure that the switch has access to the configured RADIUS servers.

�Verify that the switch is using the correct encryption key (RADIUS secret key) for each server.

�Verify that the switch has the correct IP address for each RADIUS server.

�Ensure that the radius-server timeout period is long enough for network conditions.

The switch does not authenticate a client even though the RADIUS server is properly configured and providing a response to the authentication request. If the RADIUS server configuration for authenti­ cating the client includes a VLAN assignment, ensure that the VLAN exists as a static VLAN on the switch. Refer to “How 802.1x Authentication Affects VLAN Operation” in the Access Security Guide for your switch.

During RADIUS-authenticated client sessions, access to a VLAN on the

port used for the client sessions is lost. If the affected VLAN is config­ ured as untagged on the port, it may be temporarily blocked on that port during an 802.1x session. This is because the switch has temporarily assigned another VLAN as untagged on the port to support the client access, as specified in the response from the RADIUS server. Refer to “How 802.1x Authentication Affects VLAN Operation” in the Access Security Guide for your switch.

The switch appears to be properly configured as a supplicant, but cannot gain access to the intended authenticator port on the switch to which it is connected. If aaa authentication port-access is configured for Local, ensure that you have entered the local login (operator-level) username and password of the authenticator switch into the identity and secret parame­ ters of the supplicant configuration. If instead, you enter the enable (manager- level) username and password, access will be denied.

The supplicant statistics listing shows multiple ports with the same

authenticator MAC address. The link to the authenticator may have been moved from one port to another without the supplicant statistics having been cleared from the first port. Refer to “Note on Supplicant Statistics” in the chapter on Port-Based Access Control in the Access Security Guide for your switch.

The show port-access authenticator < port-list> command shows one or more ports remain open after they have been configured with control unauthorized. 802.1x is not active on the switch. After you execute aaa port- access authenticator active, all ports configured with control unauthorized should be listed as Closed.

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