ZyXEL Communications Prestige 642 User Manual page 23

Prestige 642 ADSL Internet Access Router
Filter #: 3,1
Filter Type= TCP/IP Filter Rule
Active= Yes
IP Protocol= 6
Destination: 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:
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.
When you press [ENTER] to confirm, you will see the following screen. Note that there is only one filter
rule in this set.
8-18
Menu 21.3.1 - TCP/IP Filter Rule
IP Source Route= No
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
Log= None
Figure 8-13 Example Filter – Menu 21.3.1
Press the [SPACEBAR] 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
Select Equal
of well-known services.
here as we are
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.
Filter Configuration