ZyXEL Communications ZYAIR, User Manual

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ZyAIR Wireless Gateway Series User’s Guide
24-14 Filter and Firewall Configuration
Step 4. Press [ENTER] at the message
“
Press ENTER to confirm or ESC to cancel” to open Menu
21.1.3.1 – TCP/IP Filter Rule .
Step 5. Type 1 to configure the first filter rule. Make the entries in this menu as shown next.
Figure 24-12 Sample Filter - Menu 21.1.3.1
When you press [ENTER] to confirm, the following screen appears. 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 #=
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:
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 and there are no more
rules in this filter set to check. Select
Next if there are
more rules to check.