TRENDnet TEG-S4000I - Manual (Page 45)

Port Security
Port Security allow you to restrict specific MAC addresses to reside
in some port. For example, a dummy hub is attached to some port
for extension, and you just only allow 2 users to access this port at
the same time, you can use the port security window to set the
parameters.
Figure 5-9. The Port Security page
To restrict the number of MAC address to reside in a port, you must
do the following :
Click the “ Enable “ checkbox for that port. IF the “ Enable
“checkbox is uncheck, there is no MAC address count restriction
for that port.
Type the number in the “ Max Allowed MAC Address Count
“ edit for that port. The upper bound of this number is the “ Max
Allowed MAC Address Count per port “
Press the “ Press “ button
The “ Used Count “ will tell you how many MAC address residing
in the corresponding port now.
Note : A trunked port is not allowed to enable the port security
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