Chapter 11 Firewall Configuration
P-660W-Tx v2 User’s Guide
110
11.1.2 What You Need to Know About Firewall
DoS
Denials 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. The ZyXEL Device is pre-configured to
automatically detect and thwart all known DoS attacks.
Anti-Probing
If an outside user attempts to probe an unsupported port on your ZyXEL Device, an ICMP
response packet is automatically returned. This allows the outside user to know the ZyXEL
Device exists. The ZyXEL Device supports anti-probing, which prevents the ICMP response
packet from being sent. This keeps outsiders from discovering your ZyXEL Device when
unsupported ports are probed.
ICMP
Internet Control Message Protocol (ICMP) is a message control and error-reporting protocol
between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP)
datagrams, but the messages are processed by the TCP/IP software and directly apparent to the
application user.
DoS Thresholds
For DoS attacks, the ZyXEL Device uses thresholds to determine when to drop sessions that
do not become fully established. These thresholds apply globally to all sessions. You can use
the default threshold values, or you can change them to values more suitable to your security
requirements.
Finding Out More
See
for technical background information on WAN.
11.1.3 Firewall Rule Setup Example
The following Internet firewall rule example allows a hypothetical “My Service” connection
from the Internet.
1
Click
Firewall
in the navigation panel and click
Rule Summary
.
2
Select
WAN to LAN
in the
Packet Direction
field.
Summary of Contents for P-660W-T1 v2
Page 2: ......
Page 8: ...Safety Warnings P 660W Tx v2 User s Guide 8 ...
Page 10: ...Contents Overview P 660W Tx v2 User s Guide 10 ...
Page 18: ...Table of Contents P 660W Tx v2 User s Guide 18 ...
Page 22: ...List of Figures P 660W Tx v2 User s Guide 22 ...
Page 25: ...25 PART I Introduction Introducing the ZyXEL Device 27 Introducing the Web Configurator 31 ...
Page 26: ...26 ...
Page 30: ...Chapter 1 Introducing the ZyXEL Device P 660W Tx v2 User s Guide 30 ...
Page 36: ...Chapter 2 Introducing the Web Configurator P 660W Tx v2 User s Guide 36 ...
Page 37: ...37 PART II Setup Wizard Connection Setup Wizard 39 Media Bandwidth Management Wizard 47 ...
Page 38: ...38 ...
Page 46: ...Chapter 3 Connection Setup Wizard P 660W Tx v2 User s Guide 46 ...
Page 50: ...Chapter 4 Media Bandwidth Management Wizard P 660W Tx v2 User s Guide 50 ...
Page 52: ...52 ...
Page 83: ...Chapter 7 WAN Setup P 660W Tx v2 User s Guide 83 Figure 32 WAN Setup PPPoE ...
Page 104: ...Chapter 8 Network Address Translation NAT Screens P 660W Tx v2 User s Guide 104 ...
Page 130: ...Chapter 11 Firewall Configuration P 660W Tx v2 User s Guide 130 ...
Page 156: ...Chapter 15 Logs Screens P 660W Tx v2 User s Guide 156 ...
Page 169: ...169 PART IV Maintenance Maintenance 171 ...
Page 170: ...170 ...
Page 184: ...Chapter 17 Maintenance P 660W Tx v2 User s Guide 184 ...
Page 185: ...185 PART V Troubleshooting and Specifications Troubleshooting 187 Product Specifications 193 ...
Page 186: ...186 ...
Page 192: ...Chapter 18 Troubleshooting P 660W Tx v2 User s Guide 192 ...
Page 200: ...200 ...
Page 208: ...Appendix A Pop up Windows JavaScripts and Java Permissions P 660W Tx v2 User s Guide 208 ...
Page 226: ...Appendix C Common Services P 660W Tx v2 User s Guide 226 ...
Page 232: ...Appendix D Legal Information P 660W Tx v2 User s Guide 232 ...