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Catalyst 4500 Series, Catalyst 2948G, Catalyst 2948G-GE-TX, and Catalyst 2980G Switches Software Configuration Guide—Release 8.2GLX
78-15908-01
Chapter 30 Configuring Switch Access Using AAA
Understanding How Authentication Works
You can configure a key on the client and server. If you configure a key on the switch, it must
be the same as the one that is configured on the servers. The clients and servers
use the key to encrypt all transmitted packets. If you do not configure a key,
packets are not encrypted. The key must be fewer than 100 characters.
With , you can do the following:
•
Enable or disable authentication to determine whether a user has permission to access
the switch
•
Enable or disable authentication to determine whether a user has permission to enter
privileged mode
•
Specify a key that is used to encrypt the protocol packets
•
Specify the server on which the server daemon resides
•
Set the number of login attempts that are allowed
•
Set the timeout interval for server daemon response
•
Enable or disable the directed-request option
authentication is disabled by default. You can enable authentication and local
authentication at the same time.
If local authentication is disabled and you then disable all other authentication methods, local
authentication is reenabled automatically.
Understanding How RADIUS Authentication Works
RADIUS is a client-server authentication and authorization access protocol that is used by the NAS to
authenticate users attempting to connect to a network device. The NAS functions as a client, passing user
information to one or more RADIUS servers. The NAS permits or denies network access to a user based
on the response it receives from one or more RADIUS servers. RADIUS uses UDP for transport between
the RADIUS client and server.
You can configure a RADIUS key on the client and server. If you configure a key on the client, it must
be the same as the one that is configured on the RADIUS servers. The RADIUS clients and servers use
the key to encrypt all RADIUS-transmitted packets. If you do not configure a RADIUS key, packets are
not encrypted. The key itself is never transmitted over the network.
Note
For more information about the RADIUS protocol, refer to RFC 2138, “Remote Authentication Dial In
User Service (RADIUS).”
With RADIUS, you can do the following:
•
Enable or disable RADIUS authentication to control login access
•
Enable or disable RADIUS authentication to control enable access
•
Specify the IP addresses and User Datagram Protocol (UDP) ports of the RADIUS servers
•
Specify the RADIUS key that is used to encrypt RADIUS packets
•
Specify the RADIUS server timeout interval
•
Specify the RADIUS retransmit count
•
Specify the RADIUS server deadtime interval