AVIRA PREMIUM SECURITY SUITE, User Manual

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Reference: Configuration options
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The Avira FireWall displays the adapter rules of all existing adapters on your computer
for which a driver was installed.
A predefined adapter rule depends on the security level. You can change the security
level in the Online protection :: You can change the FireWall settings in the Control
Center or define your own adapter rules. If you have defined your own adapter rules, in
the FireWall section of the Control Center, the security level is set to custom.
Note
The default security level setting for all predefined rules of the Avira FireWall is
Medium.
ICMP protocol
The Internet Control Message Protocol (ICMP) is used to exchange error and
information messages on networks. The protocol is also used for status messages with
ping or tracer.
With this rule, you can define the incoming and outgoing blocked message types, the
behavior in case of flooding and the reaction to fragmented ICMP packets. This rule
serves for preventing so-called ICMP flood attacks, which results in an increase of the
CPU load of the attacked machine as it responds to every packet.
Predefined rules for the ICMP protocol
Setting: Low Setting:
Medium
Setting: High
Incoming blocked types: no
type
.
Outgoing blocked types:
no
type .
Assume flooding if delay
between packets is less than
50 ms.
Reject fragmented ICMP
packets.
Same rule as for
the low level.
Incoming blocked types:
several types
Outgoing blocked types:
several types
Assume flooding if delay
between packets is less than
50 ms.
Reject fragmented ICMP
packets.
Incoming blocked types: no types/several types
With a mouse click on the link a list of ICMP packet types is displayed. From this list you
can specify the desired incoming ICMP message types you want to block.
Outgoing blocked types: no types/several types
With a mouse click on the link a list of ICMP packet types is displayed. From this list you
can select the desired outgoing ICMP message types you want to block.
Flooding
With a mouse click on the link, a dialog box is displayed where you can enter the
maximum allowed ICMPA delay.
Fragmented ICMP packets
With a mouse click on the link, you have the choice to reject or not to reject fragmented
ICMP packets.