C
ONFIGURING
THE
BARRICADE
4-40
Stateful Packet
Inspection
Enabled
This option allows you to select different
application types that are using dynamic port
numbers. If you wish to use Stateful Packet
Inspection (SPI) for blocking packets, click on the
Yes radio button in the “Enable SPI and Anti-DoS
firewall protection” field and then check the
inspection type that you need, such as Packet
Fragmentation, TCP Connection, UDP Session,
FTP Service and TFTP Service.
It is called a “stateful” packet inspection because it
examines the contents of the packet to determine
the state of the communication; i.e., it ensures that
the stated destination computer has previously
requested the current communication. This is a
way of ensuring that all communications are
initiated by the recipient computer and are taking
place only with sources that are known and trusted
from previous interactions. In addition to being
more rigorous in their inspection of packets,
stateful inspection firewalls also close off ports
until a connection to the specific port is requested.
When particular types of traffic are checked, only
the particular type of traffic initiated from the
internal LAN will be allowed. For example, if the
user only checks FTP Service in the Stateful Packet
Inspection section, all incoming traffic will be
blocked except for FTP connections initiated from
the local LAN.
When hackers
attempt to enter
your network,
we can alert you
by email
Your E-mail
Address
Enter your email address.
SMTP Server
Address
Enter your SMTP server address (usually the part
of the email address following the “@” sign).
POP3 Server
Address
Enter your POP3 server address (usually the part
of the email address following the “@” sign).
User Name
Enter your email account user name.
Parameter
Defaults
Description
19216811.live