3Com 3C16685 User Manual - page 60
60
C
HAPTER
3: U
SING
THE
C
OMMAND
L
INE
I
NTERFACE
Need to Know (NTK)
In normal Hub operation, packets received
are sent to all ports irrespective of the packet destination address.
With NTK enabled, the Hub sends a packet to its destination
address, but will scramble it when sending the packet to all the
other secure ports.
1 To enable and disable DUD and NTK using the command line
interface, at the Top-level menu enter:
ethernet security
The following prompt is displayed:
Select Ethernet port (1-26): 5
2 You are then prompted to enter the security operation mode
required:
Enter mode (noSecurity, continuallyLearn, autoLearn)
[noSecurity]:
a If you enter
noSecurity
, all security features will be disabled.
b If you enter
continuallyLearn
, the following prompt is
displayed:
Enter the number of authorized addresses (0–33) [1]:
The number of authorized addresses you enter is the number of
devices allowed to transmit or receive on that port. For example, if
you enter
3
, the Hub will learn three addresses at any one time for
the specified port. When a new address is received, the most
recent three addresses received will be remembered, and the
oldest one dropped.
c If you enter
autoLearn
, the following prompt is displayed:
Enter the number of authorized addresses (0–33) [1]:
The number of authorized addresses you enter is the number of
devices allowed to transmit or receive on that port. For example, if
you enter
3
, the Hub will remember three addresses only for the
specified port. Any new addresses will not be allowed to transmit
or receive from this port.
3 If you have entered
continuallyLearn
or
autoLearn
the
following prompt is displayed:
Need to Know Mode (enable, disable) [disable]:
a If you have entered
continuallyLearn
enable or disable NTK as
required.