ZyXEL Communications Prestige 645R - Manual (Page 120)

Prestige 645 ADSL Internet Access Router
Filter Configuration 8-21
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 #= 0
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.
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.
Press the [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.