SMC Networks Barricade SMC7401BRA User Manual page 137

Configuring Firewall Settings
2. Configure any of the following settings that figure in the
[Firewall Global Information] table:
Field
Blacklist Status:
Blacklist Period(min):
Attack Protection:
Dos Protection:
Max Half open TCP
Conn.:
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Description
If you want the device to maintain and use a black list,
click [Enable]. Click [Disable] if you do not want to maintain
a list.
This field specifies the number of minutes that a
computer's IP address will remain on the black list
(i.e., all traffic originating from that computer will be
blocked from passing through any interface on the ADSL
Barricade). For more information, see Managing the Black
List on page 138.
Click the [Enable] radio button to use the built-in firewall
protections that prevent the following common types of
attacks.
IP Spoofing: Sending packets over the WAN interface
using an internal LAN IP address as the source address.
Tear Drop: Sending packets that contain overlapping
fragments.
Smurf and Fraggle: Sending packets that use the WAN or
LAN IP broadcast address as the source address.
Land Attack: Sending packets that use the same address
as the source and destination address.
Ping of Death: Illegal IP packet length.
Click the [Enable] radio button to use the following denial
of service protections: SYN DoS, ICMP DoS, Per-host
DoS protection.
This field sets the percentage of concurrent IP sessions
that can be in the half-open state. In ordinary TCP
communication, packets are in the half-open state only
briefly as a connection is being initiated; the state
changes to active when packets are being exchanged, or
closed when the exchange is complete. TCP connections
in the half-open state can use up the available IP
sessions. If the percentage is exceeded, then the half-open
sessions will be closed and replaced with new sessions
as they are initiated.