Figure 7-11 Example Filter - ZyXEL Communications Prestige 314 User Manual

P314 Broadband Sharing Gateway with 4-Port Switch
Menu 21.3.1 - TCP/IP Filter Rule
Filter #: 3,1
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= Check Next Rule
Press ENTER to Confirm or ESC to Cancel:
Press Space Bar to Toggle.
No more rules to
check to block
telnet.
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.
7-14
IP Source Route= No
IP Mask= 0.0.0.0
Port #= 23
Port # Comp= Equal
IP Mask= 0.0.0.0
Port #= 0
Port # Comp= None
Log= None
Select Equal
here as we are
looking for
packets going to
port 23 only.
Select Check Next Rule here
so that the next rule is
checked if the destination is
not the telnet port.
Figure 7-11 Example Filter
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 1060 for port numbers
of well-known services.
Filter Configuration