ZyXEL Communications Prestige 643, User Manual

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Prestige 643 ADSL Router
8-18 Filter Configuration
Figure 8-14 Example Filter – Menu 21.3.1
When you press
[ENTER]
to confirm, you will see the following screen. Note that there is only one filter
rule in this set.
Menu 21.3.1 - TCP/IP Filter Rule
Filter #: 3,1
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6 IP Source Route= No
Destination: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #= 23
Port # Comp= Equal
Source: IP Addr= 0.0.0.0
IP Mask= 0.0.0.0
Port #=
Port # Comp= None
TCP Estab= No
More= No Log= None
Action Matched= Drop
Action Not Matched= Forward
Press ENTER to Confirm or ESC to Cancel:
Press Space Bar to Toggle.
Press
[SPACE BAR]
to choose
this filter rule type. The first filter
rule type determines all subsequent
filter types within a set.
Select Yes to make the rule active.
6 is the TCP protocol.
The port number for the telnet
service (TCP protocol) is
23 . See
RFC 1060 for port numbers of
well-known services.
Select Equal here as we are
looking for packets going to port
23 only.
There are no
more rules to
check.
Select Drop here so
that the packet will be
dropped if its
destination is the telnet
port.
Select Forward here so that
the packet will be forwarded
if its destination is not the
telnet port.