Troubleshooting

Unusual Network Activity

The switch does not receive a response to RADIUS authentication

requests. In this case, the switch will attempt authentication using the secondary method configured for the type of access you are using (console, Telnet, or SSH).

There can be several reasons for not receiving a response to an authentication request. Do the following:

■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 authenticating 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 configured 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 parameters of the supplicant configuration. If instead, you enter the enable (manager- level) username and password, access will be denied.

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