9-12
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
78-11380-12
Chapter 9      Configuring IEEE 802.1x Port-Based Authentication
    Configuring IEEE 802.1x Authentication
IEEE 802.1x Configuration Guidelines
These are the IEEE 802.1x authentication configuration guidelines:
• When IEEE 802.1x is enabled, ports are authenticated before any other Layer 2 features are enabled.
• The IEEE 802.1x protocol is supported on Layer 2 static-access ports and voice VLAN ports, but it 
is not supported on these port types:
–
Trunk port—If you try to enable IEEE 802.1x on a trunk port, an error message appears, and 
IEEE 802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled port to 
trunk, the port mode is not changed.
–
Dynamic ports—A port in dynamic mode can negotiate with its neighbor to become a trunk 
port. If you try to enable IEEE 802.1x on a dynamic port, an error message appears, and IEEE 
802.1x is not enabled. If you try to change the mode of an IEEE 802.1x-enabled port to dynamic, 
the port mode is not changed.
–
Dynamic-access ports—If you try to enable IEEE 802.1x on a dynamic-access (VLAN Query 
Protocol [VQP]) port, an error message appears, and IEEE 802.1x is not enabled. If you try to 
change an IEEE 802.1x-enabled port to dynamic VLAN assignment, an error message appears, 
and the VLAN configuration is not changed.
–
EtherChannel ports—Do not configure a port that is an active or a not-yet-active member of an 
EtherChannel as an IEEE 802.1x port. If you try to enable IEEE 802.1x on an EtherChannel 
port, an error message appears, and IEEE 802.1x is not enabled. 
Quiet period  60 seconds (number of seconds that the switch remains in 
the quiet state following a failed authentication exchange 
with the client).
Retransmission time  30 seconds (number of seconds that the switch should 
wait for a response to an EAP request/identity frame 
from the client before resending the request).
Maximum retransmission number 2 times (number of times that the switch will send an 
EAP-request/identity frame before restarting the 
authentication process).
Host mode Single-host mode.
Guest VLAN None specified.
Client timeout period  30 seconds (when relaying a request from the 
authentication server to the client, the amount of time the 
switch waits for a response before resending the request 
to the client.
Authentication server timeout period  30 seconds (when relaying a response from the client to 
the authentication server, the amount of time the switch 
waits for a reply before resending the response to the 
server. This setting is not configurable.)
Table 9-2 Default IEEE 802.1x Configuration (continued)
Feature Default Setting