User manual ZYXEL P-334U

[. . . ] P-334U/P-335U 802. 11a/g Wireless Router User's Guide Version 3. 60 Edition 2 11/2006 P-334U/P-335U User's Guide Copyright Copyright © 2006 by ZyXEL Communications Corporation. The contents of this publication may not be reproduced in any part or as a whole, transcribed, stored in a retrieval system, translated into any language, or transmitted in any form or by any means, electronic, mechanical, magnetic, optical, chemical, photocopying, manual, or otherwise, without the prior written permission of ZyXEL Communications Corporation. All rights reserved. Disclaimer ZyXEL does not assume any liability arising out of the application or use of any products, or software described herein. Neither does it convey any license under its patent rights nor the patent rights of others. [. . . ] Select From and enter the time period, in 24-hour format, during which content filtering will be enforced. Click Reset to begin configuring this screen afresh Time of Day to Block (24-Hour Format) Apply Reset 12. 6 Customizing Keyword Blocking URL Checking You can use commands to set how much of a website's URL the content filter is to check for keyword blocking. See the appendices for information on how to access and use the command interpreter. 12. 6. 1 Domain Name or IP Address URL Checking By default, the ZyXEL Device checks the URL's domain name or IP address when performing keyword blocking. This means that the ZyXEL Device checks the characters that come before the first slash in the URL. For example, with the URL www. zyxel. com. tw/news/pressroom. php, content filtering only searches for keywords within www. zyxel. com. tw. 12. 6. 2 Full Path URL Checking Full path URL checking has the ZyXEL Device check the characters that come before the last slash in the URL. For example, with the URL www. zyxel. com. tw/news/pressroom. php, full path URL checking searches for keywords within www. zyxel. com. tw/news/. Use the ip urlfilter customize actionFlags 6 [disable | enable] command to extend (or not extend) the keyword blocking search to include the URL's full path. 136 Chapter 12 Content Filtering P-334U/P-335U User's Guide 12. 6. 3 File Name URL Checking Filename URL checking has the ZyXEL Device check all of the characters in the URL. For example, filename URL checking searches for keywords within the URL www. zyxel. com. tw/news/pressroom. php. Use the ip urlfilter customize actionFlags 8 [disable | enable] command to extend (or not extend) the keyword blocking search to include the URL's complete filename. Chapter 12 Content Filtering 137 P-334U/P-335U User's Guide 138 Chapter 12 Content Filtering P-334U/P-335U User's Guide CHAPT E R 1 3 IPSec VPN This chapter explains how to set up and maintain IPSec VPNs in the ZyXEL Device. This chapter applies to the P-335U. 13. 1 IPSec VPN Overview A virtual private network (VPN) provides secure communications between sites without the expense of leased site-to-site lines. A secure VPN is a combination of tunneling, encryption, authentication, access control and auditing. It is used to transport traffic over the Internet or any insecure network that uses TCP/IP for communication. Internet Protocol Security (IPSec) is a standards-based VPN that offers flexible solutions for secure data communications across a public network like the Internet. IPSec is built around a number of standardized cryptographic techniques to provide confidentiality, data integrity and authentication at the IP layer. The following figure provides one perspective of a VPN tunnel. Figure 82 VPN: Example The VPN tunnel connects the ZyXEL Device (X) and the remote IPSec router (Y). These routers then connect the local network (A) and remote network (B). Each phase establishes a security association (SA), a contract indicating what security parameters the ZyXEL Device and the remote IPSec router will use. The first phase establishes an Internet Key Exchange (IKE) SA between the ZyXEL Device and remote IPSec router. The second phase uses the IKE SA to securely establish an IPSec SA through which the ZyXEL Device and remote IPSec router can send data between computers on the local network and remote network. The following figure illustrates this. Chapter 13 IPSec VPN 139 P-334U/P-335U User's Guide Figure 83 VPN: IKE SA and IPSec SA In this example, a computer in network A is exchanging data with a computer in network B. Inside networks A and B, the data is transmitted the same way data is normally transmitted in the networks. Between routers X and Y, the data is protected by tunneling, encryption, authentication, and other security features of the IPSec SA. [. . . ] If the alternate gateway is on the LAN (and it's IP address is in the same subnet), the "triangle route" problem may occur. 1 A computer on the LAN initiates a connection by sending out a SYN packet to a receiving server on the WAN. 2 The Prestige reroutes the SYN packet through Gateway B on the LAN to the WAN. 3 The reply from the WAN goes directly to the computer on the LAN without going through the Prestige. [. . . ]