ZyXEL Communications Corporation VMG1312B10C Manuel D’Utilisation

Chapter 14 Firewall

VMG1312-B10C 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

IP Type

Select whether your IP type is IPv4 or IPv6. 

Select Protocol

Select the transport layer protocol that defines your customized port from the drop-down 
list box. The specific protocol rule sets you add in the Security > Firewall > Service > 
Add screen display in this list. 

If you want to configure a customized protocol, select Specific Service.

Protocol

This field is displayed only when you select Specific Protocol in Select Protocol.

Choose the IP port (TCP/UDP, TCP, UDP, ICMP, or ICMPv6) that defines your customized 
port from the drop-down list box.

Custom Source 
Port

This field is displayed only when you select Specific Protocol in Select Protocol.

Enter a single port number or the range of port numbers of the source.

Custom 
Destination Port

This field is displayed only when you select Specific Protocol in Select Protocol.

Enter a single port number or the range of port numbers of the destination.

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.

Enable Rate 
Limit

Select this check box to set a limit on the upstream/downstream transmission rate for the 
specified protocol.

Specify how many packets per minute or second the transmission rate is.

Scheduler Rules Select a schedule rule for this ACL rule form the drop-down list box. You can configure a 

new schedule rule by click Add New Rule. This will bring you to the Security > Scheduler 
Rules screen.

Apply

Click Apply to save your changes.

Cancel

Click Cancel to exit this screen without saving.

Access Control: Add/Edit (continued)