Draytek Vigor2100V User Manual page 62

IP Address: Specify a source and destination IP address for this filter rule
to apply to. Place the symbol ! before a particular IP Address will
prevent this rule from being applied to that IP address. It is equal to
the logical NOT operator.
Subnet Mask: Specify the Subnet Mask for the IP Address column for
this filter rule to apply to.
Operator: The operator column specifies the port number settings. If
the Start Port is empty, the Start Port and the End Port column will be
ignored. The filter rule will filter out any port number.
= : If the End Port is empty, the filter rule will set the port number to be
the value of the Start Port. Otherwise, the port number ranges
between the Start Port and the End Port (including the Start Port
and the End Port).
!= : If the End Port is empty, the port number is not equal to the value
of the Start Port. Otherwise, this port number is not between the
Start Port and the End Port (including the Start Port and End
Port).
> : Specify the port number is larger than the Start Port (includes the
Start Port).
< : Specify the port number is less than the Start Port (includes the
Start Port).
Keep State: i.e. Stateful Packet Inspection. It tracks packets and
denies unsolicited incoming data. On the protocol entry, you can
choose TCP or UDP or TCP/UDP or ICMP.
Protect Your Network
6-10