C
ONFIGURING
THE
S
WITCH
2-48
Configuring 802.1x Port Authentication
Network switches can provide open and easy access to network resources
by simply attaching a client PC. Although this automatic configuration and
access is a desirable feature, it also allows unauthorized personnel to easily
intrude and possibly gain access to sensitive network data.
The IEEE 802.1x standard defines a port-based access control procedure
that prevents unauthorized access to a network by requiring users to first
submit credentials for authentication. Access to all switch ports in a
network can be centrally controlled from a server, which means that
authorized users can use a single user ID and password for authentication
from any point within the network.
This switch uses the
Extensible Authentication
Protocol over LANs
(EAPOL) to exchange
authentication protocol
messages with the client,
and a remote RADIUS
authentication server to
verify user identity and
access rights. When a client (i.e., Supplicant) connects to a switch port, the
switch (i.e., Authenticator) responds with an EAPOL identity request. The
client provides its identity (such as a user name) in an EAPOL response to
the switch, which it forwards to the RADIUS server. The RADIUS server
verifies the client identity and sends an access challenge back to the client.
The EAP packet from the RADIUS server contains not only the challenge,
but the authentication method to be used.The client can reject the
authentication method and request another, depending on the
configuration of the client software and the RADIUS server. The
authentication method can be MD5, TLS (Transport Layer Security),
TTLS (Tunneled Transport Layer Security), or other. The client responds
to the appropriate method with its credentials, such as a password or
802.1x
client
RADIUS
server
1. Client attempts to access a switch port.
2. Switch sends client an identity request.
3. Client sends back identity information.
4. Switch forwards this to authentication server.
5. Authentication server challenges client.
6. Client responds with proper credentials.
7. Authentication server approves access.
8. Switch grants client access to this port.
Summary of Contents for 6724AL2
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Page 404: ...COMMAND LINE INTERFACE 3 216 ...
Page 406: ...TROUBLESHOOTING A 2 ...
Page 418: ...GLOSSARY Glossary 8 ...
Page 422: ...INDEX Index 4 ...
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