CLI Guide

Security Commands 949
The critical data VLAN capability allows hosts to authenticate when no
RADIUS server is reachable. This allows potentially limited access to the
network via VLAN configuration. The dead-server (all RADIUS servers
marked dead) actions are configured per interface using this command.
When the dead-server action is configured to reinitialize, the switch triggers
802.1X re-authentication of all authenticated hosts on the port. Hosts on the
voice VLAN, unauthenticated VLAN (authentication failed hosts) or guest
VLAN are not disturbed. During re-authentication, if all the servers are still
dead, the hosts are authenticated successfully into the critical data VLAN.
When the dead server action is configured to authorize, the switch authorizes
the authenticated supplicants into the critical data VLAN. Hosts on a
RADIUS assigned VLAN, voice VLAN, unauthenticated VLAN or guest
VLAN are not disturbed. Hosts authorized on the port PVID are re-
authorized into the critical VLAN.
Command History
Syntax added in version 6.6 firmware.
Example
The following example configures an interface to support a critical data
VLAN (100) and to re-authenticate hosts when no RADIUS server is
reachable.
console(config)#vlan 100
console(config-vlan100)#interface gi1/0/1
console(config-if-Gi1/0/1)#authentication event server dead action
reinitialize vlan 100
authentication event server alive action
This command configures the actions to take when at least one
authentication server is reachable. Use the no form of the command to set
the interface configuration to the default.
Syntax
authentication event server alive action reinitialize
no authentication event server alive action reinitialize