Figure 16-15 Sample Filter - Menu 21.1.9.1 - ZyXEL Communications Prestige 652 User Manual

Prestige 652 ADSL Security Router
Filter #: 9,1
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6
Destination: IP Addr= 0.0.0.0
Source: IP Addr= 0.0.0.0
TCP Estab= No
More= No
Action Matched= Drop
Action Not Matched= Forward
Press ENTER to Confirm or ESC to Cancel:
There are no
more rules to
check.
Select Drop here so that
the packet will be
dropped if its destination
is the telnet port.
Step 5.
Type 1 to configure the first filter rule. Make the entries in this menu as shown next.
When you press [ENTER] to confirm, the following screen appears. Note that there is only one filter rule in
this set.
16-16
Menu 21.1.9.1 - TCP/IP Filter Rule
IP Source Route= No
IP Mask= 0.0.0.0
Port #= 23
Port # Comp= Equal
IP Mask= 0.0.0.0
Port #=
Port # Comp= None
Log= None
Figure 16-15 Sample Filter — Menu 21.1.9.1
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
Select Equal
numbers of well-known
here as we are
services.
looking for
packets going to
port 23 only.
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.
Filter Configuration