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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter7 Configuring 802.1X Port-Based Authentication
Configuring 802.1X Authentication
This example shows how to specify the server with IP address 172.20.39.46 as the RADIUS server, to
use port 1612 as the authorization port, and to set the encryption key to rad 123, matching the key on the
RADIUS server:
Switch(config)# radius-server host 172.l20.39.46 auth-port 1612 key rad123
You can globally configure the timeout, retransmission, and encryption key valu es for a ll RA DIU S
servers by using the radius-server host global configuration command. If you want to configure th ese
options on a per-server basis, use the radius-server timeout, radius-server retransmit, and the
radius-server key global configuration commands. For more information, see the “Configuring Sett ings
for All RADIUS Servers” section on page 6-28.
You also need to configure some settings on the RADIUS server. These settings include the IP address
of the switch and the key string to be shared by both th e serve r an d th e switc h. For m or e info rmat ion,
refer to the RADIUS server documentation.
Enabling Periodic Re-Authentication
You can enable periodic 802.1X client re-authentication and specify how often it occur s. If you d o not
specify a time period before enabling re-authentication, the number of seconds betwee n
re-authentication attempts is 3600.
Automatic 802.1X client re-authentication is a global setting and cannot be set for clien ts conne cted t o
individual ports. To manually re-authenticate the client connected to a specific port, see t he “Manually
Re-Authenticating a Client Connected to a Port” section on page 7-11.
Beginning in privileged EXEC mode, follow these steps to enable periodic re-authentication of the client
and to configure the number of seconds between re-authent ic ation a ttemp ts :
To disable periodic re-authentication, use the no dot1x re-authentication global configuration
command.To return to the default number of seconds between re-authentication attempts, use the no
dot1x timeout re-authperiod global configuration command.
This example shows how to enable periodic re-authentication and set the number of seconds between
re-authentication attempts to 4000:
Switch(config)# dot1x re-authentication
Switch(config)# dot1x timeout re-authperiod 4000
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 dot1x re-authentication Enable periodic re-authentication of the client, whi ch i s disa bled by
default.
Step3 dot1x timeout re-authperiod seconds Set the number of seconds between re-authentication attempts.
The range is 1 to 4294967295; the default is 3600 seconds.
This command affects the behavior of the switch only if periodic
re-authentication is enabled.
Step4 end Return to privileged EXEC mode.
Step5 show dot1x Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.