User manual ZYXEL P-661H-D BROCHURE

[. . . ] Neither does it convey any license under its patent rights nor the patent rights of others. ZyXEL further reserves the right to make changes in any products described herein without notice. This publication is subject to change without notice. Trademarks ZyNOS (ZyXEL Network Operating System) is a registered trademark of ZyXEL Communications, Inc. Other trademarks mentioned in this publication are used for identification purposes only and may be properties of their respective owners. Copyright 2 P-661H-D/HW-D Series User's Guide Certifications Federal Communications Commission (FCC) Interference Statement This device complies with Part 15 of FCC rules. [. . . ] This is the starting global IP address (IGA). Enter 0. 0. 0. 0 here if you have a dynamic IP address from your ISP. This is the ending global IP address (IGA). This field is N/A for One-to-One, Manyto-One and Server mapping types. Local Start IP Local End IP Global Start IP Global End IP Server Mapping Only available when Type is set to Server. Set Select a number from the drop-down menu to choose a server mapping set. Chapter 8 Network Address Translation (NAT) Screens 142 P-661H-D/HW-D Series User's Guide Table 51 Edit Address Mapping Rule (continued) LABEL Edit Details Back Apply Cancel DESCRIPTION Click this link to go to the Port Forwarding screen to edit a server mapping set that you have selected in the Server Mapping Set field. Click Back to return to the previous screen. Click Apply to save your changes back to the ZyXEL Device. Click Cancel to begin configuring this screen afresh. 143 Chapter 8 Network Address Translation (NAT) Screens P-661H-D/HW-D Series User's Guide CHAPTER 9 Firewalls This chapter gives some background information on firewalls and introduces the ZyXEL Device firewall. 9. 1 Firewall Overview Originally, the term firewall referred to a construction technique designed to prevent the spread of fire from one room to another. The networking term "firewall" is a system or group of systems that enforces an access-control policy between two networks. It may also be defined as a mechanism used to protect a trusted network from an untrusted network. Of course, firewalls cannot solve every security problem. The ZyXEL Device also has packet filtering capabilities. The ZyXEL Device is installed between the LAN and the Internet. This allows it to act as a secure gateway for all data passing between the Internet and the LAN. The ZyXEL Device has one DSL/ISDN port and one Ethernet LAN port, which physically separate the network into two areas. · The DSL/ISDN port connects to the Internet. 145 Chapter 9 Firewalls P-661H-D/HW-D Series User's Guide · The LAN (Local Area Network) port attaches to a network of computers, which needs security from the outside world. These computers will have access to Internet services such as e-mail, FTP, and the World Wide Web. However, "inbound access" will not be allowed unless you configure remote management or create a firewall rule to allow a remote host to use a specific service. 9. 3. 1 Denial of Service Attacks Figure 81 Firewall Application 9. 4 Denial of Service 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. 9. 4. 1 Basics Computers share information over the Internet using a common language called TCP/IP. TCP/ IP, in turn, is a set of application protocols that perform specific functions. An "extension number", called the "TCP port" or "UDP port" identifies these protocols, such as HTTP (Web), FTP (File Transfer Protocol), POP3 (E-mail), etc. [. . . ] 1 In Internet Explorer, click Tools, Internet Options and then the Security tab. 345 Appendix M Pop-up Windows, JavaScripts and Java Permissions P-661H-D/HW-D Series User's Guide Figure 195 Internet Options 2 Click the Custom Level. . . 4 Under Active scripting make sure that Enable is selected (the default). 5 Under Scripting of Java applets make sure that Enable is selected (the default). 6 Click OK to close the window. Appendix M Pop-up Windows, JavaScripts and Java Permissions 346 P-661H-D/HW-D Series User's Guide Figure 196 Security Settings - Java Scripting Java Permissions 1 From Internet Explorer, click Tools, Internet Options and then the Security tab. [. . . ]