User`s guide

ericom D1000 modem User’s Guide 147

CHAPTER 13

Firewall

13.1 Overview

This chapter shows you how to enable the Device firewall. Use the firewall to protect your Device

and network from attacks by hackers on the Internet and control access to it. The firewall:

• allows traffic that originates from your LAN computers to go to all other networks.

• blocks traffic that originates on other networks from going to the LAN.

• blocks SYN and port scanner attacks.

By default, the Device blocks DDOS, LAND and Ping of Death attacks whether the firewall is enabled

or disabled.

The following figure illustrates the firewall action. User A can initiate an IM (Instant Messaging)

session from the LAN to the WAN (1). Return traffic for this session is also allowed (2). However

other traffic initiated from the WAN is blocked (3 and 4).

Figure 99 Default Firewall Action

13.1.1 What You Can Do in the Firewall Screens

•Use the General screen (Section 13.2 on page 149) to select the firewall protection level on the

Device.

•Use the Default Action screen (Section 13.3 on page 150) to set the default action that the

firewall takes on packets that do not match any of the firewall rules.

•Use the Rules screen (Section 13.4 on page 151) to view the configured firewall rules and add,

edit or remove a firewall rule.

•Use the DoS screen (Section 13.5 on page 156) to set the thresholds that the Device uses to

determine when to start dropping sessions that do not become fully established (half-open

sessions).

WAN

LAN