4-28
C
H
A
P
T
E
R
4:
M
A
N
A
G
I
N
G
Y
O
U
R
H
U
B
U
S
I
N
G
Q
U
I
C
K
C
O
N
F
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G
M
A
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A
G
E
R
Hub Security
The OfficeConnect
Hub 8/TP
M provides flexible
communication between your workstations and
other network equipment. It is a good idea to
configure security for the hub to protect your
network from unwanted communications.
Security can be performed at two levels:
■
Port
— Configure security for an individual port.
■
Hub
— Configure security for one or more ports at a
time.
The way you set up your security depends on what
you want to do. For example, if you have one device
connected to a specific port, you would manage at
port
level to secure that connection. If you have
several devices that you want to connect to any of a
number of ports, you would manage at
hub
level to
secure that connection.
If you simply want to disable a port, see
“Configuring a Port” on page 4-25
.
3Com’s security is very advanced but easy to set up.
It works by learning in a number of ways what
devices are communicating through its ports. You
can configure the hub to react in two ways:
■
Disconnect Unknown Device (DUD)
— If the hub
detects a communication from an unknown device
at a port, it can disable that port to prevent
further
communication.
■
Need To Know (NTK)
— If a frame is to be forwarded
from a port, the destination address of the frame is
checked and if it does not match the device learnt
for that port, the frame is scrambled to prevent the
communication from being intercepted.
16710.bk : MANAGING.FRM Page 28 Tuesday, October 7, 1997 11:38 AM
