ZyXEL Communications Internet Security Gateway ZyWALL 2 Series - Manual (Page 450)

ZyWALL 2 Series User’s Guide
30-14 Filter Configuration
Figure 30-9 Example Filter: Menu 21.1.3.1
When you press [ENTER] to confirm, you will see the following screen. Note that there is only one filter rule
in this set.
Menu 21.1.3.1 - 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.
Press [SPACE BAR] and then
[ENTER] 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 you 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.