D-Link DSL-504G manual Firewall, Attacks Port Scans

DSL-504G ADSL Router User’s Guide

Firewall

The Firewall Configuration menu allows the Router to enforce specific predefined policies intended to protect against certain common types of attacks. There are two general types of protection that can be enabled on the Router, as well as filtering for specific packet types sometimes used by hackers.

Figure 4- 5. Firewall Configuration Menu

Under Protection Policy you can choose to Enable or Disable protection against a basket of attack and scan types included as Attack Protection. When Attack Protection is enabled, it will create a firewall policy to protect your network against the following attack types and port scans:

Attacks	Port Scans
Ping of Death Attack	Fragmentation Scan	Null Scan
Tear Drop Attack	UDP Scan	RST Scan
IP Spoofing Attack	ICMP Scan	SYNACK Scan
Smurf Attack	TCP Session Scan	FIN Scan
Land Attack	Xmas Scan	ACK Scan

You can also choose to Enable or Disable protection against various denial-of-service type attacks with the DOS Protection option.

A "denial-of-service" attack is characterized by an explicit attempt by attackers to prevent legitimate users of a service from using that service. Examples include: attempts to "flood" a network, thereby preventing legitimate network traffic, attempts to disrupt connections between two machines, thereby preventing access to a service, attempts to prevent a particular individual from accessing a service, or, attempts to disrupt service to a specific system or person.

The Service Filtering options allow you to block FTP, Telnet or response to Pings from the external network. Check the category you want to block to enable filtering of that type of packet.

When you have selected the desired Firewall policies, click the Apply button to enforce the policies. Remember to save any configuration changes.

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