Figure 15-12 Example Filter - Menu 21.1.3.1 - ZyXEL Communications ZyXEL ZyWALL 50 User Manual

Step 3. Enter a descriptive name or comment in the Edit Comments field and press [ENTER].
Step 4. Press [ENTER] at the message [Press ENTER to confirm] to open Menu 21.1.1 - Filter
Rules Summary.
Step 5. Enter 1 to configure the first filter rule (the only filter rule of this set). Make the entries in this
menu as shown in the following figure.
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
Action Matched= Drop
Action Not Matched= Forward
Press ENTER to Confirm or ESC to Cancel:
Press Space Bar to Toggle.
There are no more rules to
check.
Select Drop here so that the packet
will be dropped if its destination is
the telnet port.
Filter Configuration
Menu 21.1.3.1 - TCP/IP Filter Rule
Log= None
Select Equal here as you are looking for
packets going to port 23 only.
Figure 15-12 Example Filter — Menu 21.1.3.1
ZyWALL 50 Internet Security Gateway
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 Forward here so that the packet
will be forwarded if its destination is not
the telnet port.
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