Draytek VIGOR 2700GE/E User Manual page 48

Keep State
Fragments
Vigor2700Ge/e User's Guide
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).
This function should work along with Direction, Protocol, IP address,
Subnet Mask, Operator, Start Port and End Port settings. It is used
for Data Filter only.
Keep State is in the same nature of modern term Stateful Packet
Inspection. It tracks packets, and accept the packets with appropriate
characteristics showing its state is legal as the protocol defines. It
will deny unsolicited incoming data. You may select protocols from
any, TCP, UDP, TCP/UDP, ICMP and IGMP.
Specify the action for fragmented packets. And it is used for Data
Filter only.
Don't care -No action will be taken towards fragmented packets.
Unfragmented -Apply the rule to unfragmented packets.
Fragmented - Apply the rule to fragmented packets.
Too Short - Apply the rule only to packets that are too short to contain
a complete header.
43