Figure 168 Example Filter Rules Summary: Menu 21.1.3 - ZyXEL Communications ZyAir G-2000 PlusV2 User Manual

ZyXEL G-2000 Plus v2 User's Guide
• The Port # for the telnet service (TCP protocol) is 23. See RFC 1060 for port numbers of
well-known services.
• Select Equal from the Port # Comp field as you are looking for packets going to port 23
only.
• Select Drop in the Action Matched field so that the packet will be dropped if its
destination is the telnet port.
• Select Forward from the Action Not Matched field so that the packet will be forwarded
if its destination is not the telnet port.
• Press [SPACE BAR] and then [ENTER] to choose this filter rule type. The first filter rule
type determines all subsequent filter types within a set.
When you press [ENTER] to confirm, you will see the following screen. Note that there is
only one filter rule in this set.

Figure 168 Example Filter Rules Summary: Menu 21.1.3

# A Type
- - ---- --------------------------------------------------------- - - -
1 Y IP
2 N
3 N
4 N
5 N
6 N
This shows you that you have configured and activated (A = Y) a TCP/IP filter rule (Type =
IP, Pr = 6) for destination telnet ports (DP = 23).
M = N means an action can be taken immediately. The action is to drop the packet (m = D) if
the action is matched and to forward the packet immediately (n = F) if the action is not
matched no matter whether there are more rules to be checked (there aren't in this example).
After you've created the filter set, you must apply it.
1 Enter 11 from the main menu to go to menu 11.
2 Go to the Edit Filter Sets field, press [SPACE BAR] to select Yes and press [ENTER].
3 This brings you to menu 11.5. Apply a filter set (our example filter set 3).
4 Press [ENTER] to confirm after you enter the set numbers and to leave menu 11.5.
308
Menu 21.1.3 - Filter Rules Summary
Pr=6, SA=0.0.0.0, DA=0.0.0.0, DP=23
Enter Filter Rule Number (1-6) to Configure:
Filter Rules
Chapter 28 Filter Configuration
M m n
N D F