VoIP/(802.11g) ADSL2+ (VPN) Firewall Router
Chapter 4: Configuration
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Intrusion Detection
The router’s
Intrusion Detection System
(IDS) is used to detect hacker attacks and intrusion attempts
from the Internet. If the IDS function of the firewall is enabled, inbound packets are filtered and blocked
depending on whether they are detected as possible hacker attacks, intrusion attempts or other
connections that the router determines to be suspicious.
Blacklist
: If the router detects a possible attack, the source IP or destination IP address will be added to
the Blacklist. Any further attempts using this IP address will be blocked for the time period specified as the
Block Duration
. The default setting for this function is false (disabled). Some attack types are denied
immediately without using the Blacklist function, such as
Land attack
and
Echo/CharGen scan
.
Intrusion Detection
: If enabled, IDS will block Smurf attack attempts. Default is false.
Block Duration:
~
Victim Protection Block Duration
: This is the duration for blocking
Smurf
attacks. Default
value is 600 seconds.
~
Scan Attack Block Duration
: This is the duration for blocking hosts that attempt a possible
Scan attack. Scan attack types include
X’mas scan, IMAP SYN/FIN scan
and similar attempts.
Default value is 86400 seconds.
~
DoS Attack Block Duration
: This is the duration for blocking hosts that attempt a possible
Denial of Service (DoS) attack. Possible DoS attacks this attempts to block include
Ascend Kill
and
WinNuke
. Default value is 1800 seconds.
Max TCP Open Handshaking Count
: This is a threshold value to decide whether a
SYN Flood
attempt
is occurring or not. Default value is 100 TCP SYN per seconds.
Max PING Count
: This is a threshold value to decide whether an
ICMP Echo Storm
is occurring or not.
Default value is 15 ICMP Echo Requests (PING) per second.
Max ICMP Count
: This is a threshold to decide whether an
ICMP flood
is occurring or not. Default value
is 100 ICMP packets per seconds except ICMP Echo Requests (PING).
For
SYN Flood
,
ICMP Echo Storm
and
ICMP flood
, IDS will just warn the user in the Event Log. It cannot
protect against such attacks.