How to monitor failed authentications in wired Dot1X

bjoern.reese · ‎05-07-2009

Hi all,

I'd be glad if someone could point me to the right track for getting a clear picture of failed authentications with a 2960, 802.1X and EAP-TLS. I've assigned guest vlans to the switch-ports and I'm able to see successfull authentications in the (free)radius-server logs, but I don't see any message in logs if a client is assigned to the guest-vlan. One might say, this is part of the radius-server, agreed, but what if the client does not even try to authenticate with dot1x, because it may lack this function, or uses another method by default? Is anyone else here, who made a similar experience within a bigger installation and solved this? Maybe SNMP-Traps are an Option here? I'd simply like to see what's going on.

umedryk · ‎05-14-2009

When a port is in multiple-authentication mode, all the VLAN assignment features, including the RADIUS server supplied VLAN assignment, the Guest VLAN, the Inaccessible Authentication Bypass, and the Authentication Failed VLAN do not activate.

You can configure a restricted VLAN (also referred to as an authentication failed VLAN) for each 802.1x port on a switch to provide limited services to clients that cannot access the guest VLAN. These clients are 802.1x-compliant and cannot access another VLAN because they fail the authentication process. A restricted VLAN allows users without valid credentials in an authentication server (typically, visitors to an enterprise) to access a limited set of services. The administrator can control the services available to the restricted VLAN.

http://www.cisco.com/en/US/docs/switches/lan/catalyst2960/software/release/12.2_50_se/configuration/guide/sw8021x.html#wp1270660