ZyXEL Communications EMG5324-D10A ユーザーズマニュアル

 Chapter 13 Firewall

EMG5324-D10A User’s Guide

DoS (Denial of Service) attacks can flood your Internet connection with invalid packets and 
connection requests, using so much bandwidth and so many resources that Internet access 
becomes unavailable. 

Use the DoS screen to activate protection against DoS attacks. Click Security > Firewall > DoS 
to display the following screen. 

Security > Firewall > DoS

The following table describes the labels in this screen. 

This section provides some technical background information about the topics covered in this 
chapter.

Source/
Destination Port

These fields are displayed if you select TCP or UDP as the IP port.
Select Single to specify one port only or Range to specify a span of ports that define your 
customized service. If you select Any, the service is applied to all ports.
Type a single port number or the range of port numbers that define your customized 
service.

Policy

Use the drop-down list box to select whether to discard (DROP), deny and send an ICMP 
destination-unreachable message to the sender of (REJECT) or allow the passage of 
(ACCEPT) packets that match this rule.

Direction 

Use the drop-down list box to select the direction of traffic to which this rule applies.

Apply

Click Apply to save your changes.

Cancel

Click Cancel to exit this screen without saving.

Access Control: Add/Edit (continued)

Security > Firewall > DoS

DoS Protection 
Blocking

Select Enable to enable protection against DoS attacks.

Apply

Click Apply to save your changes.

Cancel

Click Cancel to exit this screen without saving.