3Com 3C17203 - SuperStack 3 Switch 4400, Руководство по внедрению

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What is Network Login? 105
NBX mode offers a reduced level of network security because the
Switch port is accessible at all times to allow NBX phone traffic to be
automatically forwarded.
When the port is configured in the Network Login with NBX operational
mode and the client device is removed, the Switch does not receive a link
down event and the port will continue to be authorized. This is because
the client device is not directly connected to the Switch.
What is Network
Login?
Network Login controls user access at the network edge by blocking or
unblocking access on a per-port basis.
When a client device attempts to connect to a Switch port, the user is
challenged to provide their identity and authentication credentials in the
form of a user name and password. The user information is then sent to a
remote RADIUS server in the network for authentication. This information
must be successfully authenticated and authorized before the client
device is granted access to the network.
For further information about RADIUS, see “What is RADIUS?” on
page 112 .
The client device must be directly connected to the Switch port (no
intervening switch or hub) as the Switch uses the link status to determine
if an authorized client device is connected. Network Login will not
operate correctly if there is a “bridge” device between the client device
and the Switch port, or if there are multiple client devices attached via a
hub to the Switch port.
In addition to providing protection against unauthorized network access,
Network Login also allows the user of a port to be identified. This user
identification information can be used for service accounting or billing, or
to help network administrators resolve problems.
Network Login is a feature that is particularly relevant in publicly
accessible networks, such as education campuses or conference facilities,
which often have limited control over physical access to areas with live
network connections.
Network Login is based on the IEEE Std 802.1X-2001, which defines a
mechanism for user authentication for port-based network access
control.