Example Filter - Menu 21.1.1 - ZyXEL Communications Prestige 100L User Manual

Prestige 100L IDSL 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 is dropped if
its destination is the
telnet port.
When you press the [Enter] key to confirm, the following screen appears. Note that there is only one filter
rule in this set.
6-14
Menu 21.1.1 - 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 6-7
Select Equal
here as we are
looking for
packets going to
port 23 only.
Select Forward here so that
the packet is forwarded if its
destination is not the telnet
port.
Example Filter – Menu 21.1.1
Press the [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 1700 for port numbers
of well-known services.
Filters