The Dos Protection Screen - ZyXEL Communications LTE3202-M430 User Manual

9.2 The DoS Protection Screen

Use this screen to enable DoS (Denial of Service) protection on the LTE3202-M430.
Denial of Service (DoS) attacks are aimed at devices and networks with a connection to the Internet.
Their goal is not to steal information, but to disable a device or network so users no longer have access
to network resources.
SYN attack floods a targeted system with a series of SYN packets. Each packet causes the targeted
system to issue a SYN-ACK response, While the targeted system waits for the ACK that follows the SYN-
ACK, it queues up all outstanding SYN-ACK responses on what is known as a backlog queue. SYN-ACKs
are moved off the queue only when an ACK comes back or when an internal timer (which is set a
relatively long intervals) terminates the TCP three-way handshake. Once the queue is full, the system will
ignore all incoming SYN requests, making the system unavailable for legitimate users.
ICMP attack floods a targeted system with ICMP/PING echo requests.
Click Configuration > Firewall > DoS Protection to open the following screen.
Figure 43 Configuration > Firewall > DoS Protection
The following table describes the labels on this screen.
Table 26 Configuration > Firewall > DoS Protection
LABEL
DoS Protection
Enable DoS protection
SYN Flood
ICMP Flood
Apply
Cancel
Chapter 9 Firewall
DESCRIPTION
Select this check box to enable DoS protection.
Select this to enable TCP SYN flood attack protection and specify the maximum
number of packets allowed per second. If the TCP SYN packets exceed the
threshold the LTE3202-M430 drops the over flooding packets.
Select this to enable ICMP flood attack protection and specify the maximum
number of packets allowed per second. If the ICMP packets exceed the threshold
the LTE3202-M430 drops the over flooding packets.
Click Apply to save your changes back to the LTE3202-M430.
Click Cancel to reload the previous configuration for this screen.
LTE3202-M430 User's Guide
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