ZyXEL Communications P-1100 manual Executing an IP Filter

Prestige 1100 Internet Access Router

The following diagram illustrates the logic flow of an IP filter.

Packet into IP Filter

Filter Active?	No
Yes
Apply SrcAddrMask
to Src Addr
Check Src	Not Matched
IP Addr
Matched
Apply DestAddrMask
to Dest Addr
Check Dest	Not Matched
IP Addr
Matched
Check	Not Matched
IP Protocol
Matched
Check Src &	Not Matched
Dest Port
Matched
More?	Yes
No		Action Not Matched
Action Matched	Check Next Rule	Check Next Rule
		Drop	Forward
Drop	Forward

Drop Packet Check Next Rule Accept Packet

Figure 8-6 Executing an IP Filter

8-10 Filter Configuration