ZyXEL Communications ZyWALL 50 User Manual

ZyWALL 50

Internet Security Gateway

User’s Guide

Version 3.50

November 2001

ZyWALL 50 Internet Security Gateway

Copyright

Copyright © 2001 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.

Published by 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.

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.

ii Copyright

ZyWALL 50 Internet Security Gateway

Federal Communications Commission

(FCC) Interference Statement

This device complies with Part 15 of FCC rules. Operation is subject to the following two conditions:

• This device may not cause harmful interference.

• This device must accept any interference received, including interference that may cause undesired

operations.

This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to

Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful

interference in a commercial environment. This equipment generates, uses, and can radiate radio frequency

energy, and if not installed and used in accordance with the instructions, may cause harmful interference to

radio communications.

If this equipment does cause harmful interference to radio/television reception, which can be determined by

turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of

the following measures:

1. Reorient or relocate the receiving antenna.

2. Increase the separation between the equipment and the receiver.

3. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

4. Consult the dealer or an experienced radio/TV technician for help.

Notice 1

Changes or modifications not expressly approved by the party responsible for compliance could void the

user's authority to operate the equipment.

FCC iii

ZyWALL 50 Internet Security Gateway

Information for Canadian Users

The Industry Canada label identifies certified equipment. This certification means that the equipment meets

certain telecommunications network protective operation and safety requirements. The Industry Canada

label does not guarantee that the equipment will operate to a user's satisfaction.

Before installing this equipment, users should ensure that it is permissible to be connected to the facilities

of the local telecommunications company. The equipment must also be installed using an acceptable

method of connection. In some cases, the company's inside wiring associated with a single line individual

service may be extended by means of a certified connector assembly. The customer should be aware that

compliance with the above conditions may not prevent degradation of service in some situations.

Repairs to certified equipment should be made by an authorized Canadian maintenance facility designated

by the supplier. Any repairs or alterations made by the user to this equipment, or equipment malfunctions,

may give the telecommunications company cause to request the user to disconnect the equipment.

For their own protection, users should ensure that the electrical ground connections of the power utility,

telephone lines, and internal metallic water pipe system, if present, are connected together. This precaution

may be particularly important in rural areas.

Caution

Users should not attempt to make such connections themselves, but should contact the appropriate electrical

inspection authority, or electrician, as appropriate.

Note

This digital apparatus does not exceed the Class A limits for radio noise emissions from digital apparatus

set out in the radio interference regulations of Industry Canada.

iv Information for Canadian Users

Standard

• EN 55022

• EN 61000-3-2

• EN 61000-3-3

• EN 61000-4-2

• EN 61000-4-3

• EN 61000-4-4

• EN 61000-4-5

• EN 61000-4-6

• EN 61000-4-8

• EN 61000-4-11

ZyWALL 50 Internet Security Gateway

Declaration of Conformity

We, the Manufacturer/Importer,

ZyXEL Communications Corp.

No. 6, Innovation Rd. II,

Science-Based Industrial Park,

Hsinchu, Taiwan, 300 R.O.C

declare that the product

ZyWALL 50

is in conformity with

(reference to the specification under which conformity is declared)

Standard Item

Radio disturbance characteristics — Limits and method of
measurement.

Disturbance in supply system caused by household appliances
and similar electrical equipment “Harmonics”.

Disturbance in supply system caused by household appliances
and similar electrical equipment “Voltage fluctuations”.

Electrostatic discharge immunity test — Basic EMC Publication 1995
Radiated, radio-frequency, electromagnetic field immunity test 1996
Electrical fast transient / burst immunity test - Basic EMC

Publication
Surge immunity test 1995
Immunity to conducted disturbances, induced by radio-frequency

fields
1993
Voltage dips, short interruptions and voltage variations immunity

tests

Version

1994

1995

1995

1995

1996

1994

Certifications

Refer to the product page at www.zyxel.com

.

Declaration of Conformity v

ZyWALL 50 Internet Security Gateway

ZyXEL Limited Warranty

ZyXEL warrants to the original end user (purchaser) that this product is free from any defects in materials or
workmanship for a period of up to two years from the date of purchase. During the warranty period, and upon
proof of purchase, should the product have indications of failure due to faulty workmanship and/or materials,
ZyXEL will, at its discretion, repair or replace the defective products or components without charge for
either parts or labor, and to whatever extent it shall deem necessary to restore the product or components to
proper operating condition. Any replacement will consist of a new or re-manufactured functionally
equivalent product of equal value, and will be solely at the discretion of ZyXEL. This warranty shall not
apply if the product is modified, misused, tampered with, damaged by an act of God, or subjected to
abnormal working conditions.

Note

Repair or replacement, as provided under this warranty, is the exclusive remedy of the purchaser. This
warranty is in lieu of all other warranties, express or implied, including any implied warranty of
merchantability or fitness for a particular use or purpose. ZyXEL shall in no event be held liable for indirect
or consequential damages of any kind of character to the purchaser.
To obtain the services of this warranty, contact ZyXEL's Service Center for your Return Material
Authorization number (RMA). Products must be returned Postage Prepaid. It is recommended that the unit be
insured when shipped. Any returned products without proof of purchase or those with an out-dated warranty
will be repaired or replaced (at the discretion of ZyXEL) and the customer will be billed for parts and labor.
All repaired or replaced products will be shipped by ZyXEL to the corresponding return address, Postage
Paid. This warranty gives you specific legal rights, and you may also have other rights that vary from country
to country.

Online Registration

Don’t forget to register your ZyXEL product (fast, easy online registration at www.zyxel.com
product updates and information.

vi ZyXEL Limited Warranty

) for free future

ZyWALL 50 Internet Security Gateway

A

Customer Support

Please have the following information ready when you contact customer support.

• Product model and serial number.

• Information in Menu 24.2.1 – System Information.

• Warranty Information.

• Date that you received your device.

• Brief description of the problem and the steps you took to solve it.

METHOD

LOCATION

WORLDWIDE

USTRIA

[e-mail]

[e-mail]

[e-mail]

[e-mail] [phone]

[e-mail]

[e-mail] [phone] www.zyxel.dk SCANDINAVIA

[e-mail]

[e-mail] [phone] www.zyxel.at

[e-mail] [phone] ftp.zyxel.at

[e-mail] [phone] www.zyxel.de GERMANY

[e-mail]

[e-mail] [phone] www.zyxel.com.my MALAYSIA

[e-mail]

E-MAIL

SUPPORT/SALES

[phone] ftp.europe.zyxel.com

[phone] ftp.zyxel.com

[phone] ftp.zyxel.dk

[phone]

[phone]

TELEPHONE/FAX WEB SITE/ FTP SITE REGULAR MAIL

[phone] www.zyxel.com

800-255-4101

www.europe.zyxel.com

www.zyxel.com NORTH AMERICA

ZyXEL Communications Corp.,
6 Innovation Road II, Science­Based Industrial Park,
HsinChu, Taiwan 300, R.O.C.

ZyXEL Communications Inc.,
1650 Miraloma Avenue,
Placentia, CA 92870, U.S.A.

ZyXEL Communications A/S,
Columbusvej 5, 2860 Soeborg,
Denmark.

ZyXEL Communications
Services GmbH. Thaliastrasse
125a/2/2/4 A-1160 Vienna,
Austria

ZyXEL Deutschland GmbH.
Adenauerstr. 20/A4 D-52146
Wuerselen, Germany

Lot B2-06, PJ Industrial Park,
Section 13, Jalan Kemajuan,
46200 Petaling Jaya Selangor
Darul Ehasn, Malaysia

Customer Support vii

P312 Broadband Security Gateway

Table of Contents

Copyright..................................................................................................................................................... ii

Federal Communications Commission (FCC) Interference Statement ................................................. iii

Information for Canadian Users............................................................................................................... iv

ZyXEL Limited Warranty......................................................................................................................... vi

Customer Support..................................................................................................................................... vii

List of Figures........................................................................................................................................... xix

List Of Tables ......................................................................................................................................... xxvi

Preface..................................................................................................................................................... xxxi

GETTING STARTED...................................................................................................................................... I

Chapter 1 Getting to Know Your ZyWALL...........................................................................................1-1

1.1 The ZyWALL 50 Internet Security Gateway ............................................................................. 1-1

1.2 Features of The ZyWALL 50 ..................................................................................................... 1-1

1.3 Applications for the ZyWALL 50 .............................................................................................. 1-4

1.3.1 Secure Broadband Internet Access via Cable or DSL Modem ........................................... 1-4

1.3.2 VPN Application ................................................................................................................ 1-5

Chapter 2 Hardware Installation............................................................................................................2-1

2.1 Front Panel LEDs and Back Panel Ports .................................................................................... 2-1

2.1.1 Front Panel LEDs ............................................................................................................... 2-1

2.2 ZyWALL 50 Rear Panel and Connections................................................................................. 2-2

2.3 Additional Installation Requirements......................................................................................... 2-5

Chapter 3 Initial Setup ............................................................................................................................ 3-1

3.1 Turning On Your ZyWALL ....................................................................................................... 3-1

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3.1.1 Initial Screen.......................................................................................................................3-1

3.1.2 Entering the Password.........................................................................................................3-1

3.2 Navigating the SMT Interface ....................................................................................................3-2

3.2.1 Main Menu..........................................................................................................................3-3

3.2.2 System Management Terminal Interface Summary............................................................3-3

3.2.3 SMT Menus at a Glance .....................................................................................................3-5

3.3 Changing the System Password..................................................................................................3-7

3.4 Resetting the ZyWALL ..............................................................................................................3-8

3.4.1 Methods of Restoring Factory-Defaults.............................................................................. 3-8

3.4.2 Procedure To Use The Reset Button...................................................................................3-9

Chapter 4 General And WAN Setup .......................................................................................................4-1

4.1 System Name .............................................................................................................................. 4-1

4.2 Dynamic DNS............................................................................................................................. 4-1

4.3 WAN Setup.................................................................................................................................4-3

Chapter 5 LAN Setup...............................................................................................................................5-1

5.1 Introduction.................................................................................................................................5-1

5.2 LAN Port Filter Setup.................................................................................................................5-1

5.3 TCP/IP and DHCP for LAN .......................................................................................................5-1

5.3.1 Factory LAN Defaults.........................................................................................................5-2

5.3.2 DHCP Configuration ..........................................................................................................5-2

5.3.3 IP Address and Subnet Mask.............................................................................................. 5-2

5.3.4 Private IP Addresses ........................................................................................................... 5-3

5.3.5 RIP Setup............................................................................................................................ 5-4

5.3.6 IP Multicast.........................................................................................................................5-4

5.3.7 IP Alias ............................................................................................................................... 5-5

5.4 TCP/IP and DHCP Ethernet Setup Menu ...................................................................................5-5

5.4.1 IP Alias Setup ..................................................................................................................... 5-7

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P312 Broadband Security Gateway

Chapter 6 Internet Access ....................................................................................................................... 6-1

6.1 Internet Access Setup ................................................................................................................. 6-1

6.1.1 Ethernet Encapsulation....................................................................................................... 6-1

6.1.2 PPTP Encapsulation ........................................................................................................... 6-2

6.1.3 Configuring the PPTP Client.............................................................................................. 6-3

6.1.4 PPPoE Encapsulation .........................................................................................................6-4

6.2 Basic Setup Complete................................................................................................................. 6-5

ADVANCED APPLICATIONS ..................................................................................................................... II

Chapter 4 Remote Node Setup................................................................................................................ 4-1

4.1 Remote Node Profile .................................................................................................................. 4-1

4.1.1 Ethernet Encapsulation....................................................................................................... 4-1

4.1.2 PPPoE Encapsulation .........................................................................................................4-3

4.1.3 PPTP Encapsulation ........................................................................................................... 4-5

4.2 Editing TCP/IP Options (with Ethernet Encapsulation)............................................................. 4-7

4.2.1 Editing TCP/IP Options (with PPTP Encapsulation).......................................................... 4-8

4.2.2 Editing TCP/IP Options (with PPPoE Encapsulation)...................................................... 4-10

4.3 Remote Node Filter .................................................................................................................. 4-10

Chapter 5 IP Static Route Setup ............................................................................................................. 5-1

5.1 IP Static Route Setup.................................................................................................................. 5-2

Chapter 6 Network Address Translation (NAT).................................................................................... 6-1

6.1 Introduction ................................................................................................................................ 6-1

6.1.1 NAT Definitions.................................................................................................................6-1

6.1.2 What NAT Does................................................................................................................. 6-2

6.1.3 How NAT Works ............................................................................................................... 6-2

6.1.4 NAT Application................................................................................................................ 6-3

6.1.5 NAT Mapping Types.......................................................................................................... 6-4

6.2 Using NAT ................................................................................................................................. 6-6

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ZyWALL 50 Internet Security Gateway

6.2.1 SUA (Single User Account) Versus NAT .......................................................................... 6-6

6.2.2 Applying NAT....................................................................................................................6-6

6.3 NAT Setup .................................................................................................................................. 6-8

6.3.1 Address Mapping Sets ........................................................................................................6-8

6.4 NAT Server Sets – Port Forwarding.........................................................................................6-13

6.4.1 Configuring a Server behind NAT ....................................................................................6-14

6.5 General NAT Examples............................................................................................................6-16

6.5.1 Internet Access Only.........................................................................................................6-16

6.5.2 Example 2: Internet Access with an Inside Server............................................................ 6-17

6.5.3 Example 3: Multiple Public IP Addresses With Inside Servers........................................ 6-18

6.5.4 Example 4: NAT Unfriendly Application Programs.........................................................6-22

FIREWALL AND CONTENT FILTERS.....................................................................................................III

Chapter 7 Firewalls..................................................................................................................................7-1

7.1 What Is a Firewall?..................................................................................................................... 7-1

7.2 Types of Firewalls ......................................................................................................................7-1

7.2.1 Packet Filtering Firewalls ...................................................................................................7-1

7.2.2 Application-level Firewalls.................................................................................................7-1

7.2.3 Stateful Inspection Firewalls...............................................................................................7-2

7.3 Introduction to ZyXEL’s Firewall ..............................................................................................7-2

7.4 Denial of Service ........................................................................................................................7-3

7.4.1 Basics.................................................................................................................................. 7-3

7.4.2 Types of DoS Attacks......................................................................................................... 7-4

7.5 Stateful Inspection ......................................................................................................................7-7

7.5.1 Stateful Inspection Process .................................................................................................7-8

7.5.2 Stateful Inspection and the ZyWALL................................................................................. 7-9

7.5.3 TCP Security..................................................................................................................... 7-10

7.5.4 UDP/ICMP Security .........................................................................................................7-10

7.5.5 Upper Layer Protocols......................................................................................................7-11

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7.6 Guidelines For Enhancing Security With Your Firewall.......................................................... 7-11

7.6.1 Security In General........................................................................................................... 7-12

7.7 Packet Filtering Vs Firewall ..................................................................................................... 7-12

7.7.1 Packet Filtering:................................................................................................................ 7-13

7.7.2 Firewall............................................................................................................................. 7-13

Chapter 8 Introducing the ZyWALL Firewall.......................................................................................8-1

8.1 Remote Management and the Firewall....................................................................................... 8-1

8.2 Access Methods.......................................................................................................................... 8-1

8.3 Using ZyWALL SMT Menus..................................................................................................... 8-1

8.3.1 Activating the Firewall ....................................................................................................... 8-1

8.3.2 Viewing the Firewall Log................................................................................................... 8-2

Chapter 9 Using the ZyWALL Web Configurator ................................................................................ 9-1

9.1 Web Configurator Login and Main Menu Screens..................................................................... 9-1

9.2 Enabling the Firewall ................................................................................................................. 9-3

9.3 E-mail ......................................................................................................................................... 9-3

9.3.1 Alerts .................................................................................................................................. 9-3

9.3.2 Logs.................................................................................................................................... 9-4

9.3.3 SMTP Error Messages........................................................................................................ 9-6

9.3.4 Example E-mail Log........................................................................................................... 9-6

9.4 Attack Alert ................................................................................................................................ 9-7

9.4.1 Threshold Values................................................................................................................9-7

9.4.2 Half-Open Sessions ............................................................................................................ 9-8

Chapter 10 Creating Custom Rules...................................................................................................... 10-1

10.1 Rules Overview .................................................................................................................... 10-1

10.2 Rule Logic Overview ........................................................................................................... 10-1

10.2.1 Rule Checklist ..................................................................................................................10-1

10.2.2 Security Ramifications ..................................................................................................... 10-2

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ZyWALL 50 Internet Security Gateway

10.2.3 Key Fields For Configuring Rules....................................................................................10-2

10.3 Connection Direction ............................................................................................................ 10-3

10.3.1 LAN to WAN Rules..........................................................................................................10-3

10.3.2 WAN to LAN Rules..........................................................................................................10-4

10.4 Rule Summary ......................................................................................................................10-4

10.5 Predefined Services............................................................................................................... 10-7

10.5.1 Creating/Editing Firewall Rules......................................................................................10-10

10.5.2 Source and Destination Addresses.................................................................................. 10-11

10.6 Timeout...............................................................................................................................10-13

10.6.1 Factors Influencing Choices for Timeout Values ...........................................................10-13

Chapter 11 Custom Ports....................................................................................................................... 11-1

11.1 Introduction........................................................................................................................... 11-1

11.2 Creating/Editing A Custom Port........................................................................................... 11-3

Chapter 12 Logs .....................................................................................................................................12-1

12.1 Log Screen ............................................................................................................................12-1

Chapter 13 Example Firewall Rules.....................................................................................................13-1

13.1 Examples............................................................................................................................... 13-1

13.1.1 Example 1: Firewall Rule To Allow Web Service From The Internet..............................13-1

13.1.2 Example 2: Small Office With Mail, FTP and Web Servers ............................................13-6

13.1.3 Example 3: DHCP Negotiation and Syslog Connection from the Internet.....................13-12

Chapter 14 Content Filtering ................................................................................................................14-1

14.1 Categories .............................................................................................................................14-1

14.1.1 Restrict Web Features.......................................................................................................14-1

14.1.2 Filter List ..........................................................................................................................14-1

14.1.3 Days and Times ................................................................................................................14-1

14.2 Update List............................................................................................................................ 14-1

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14.3 Exempt Computers ............................................................................................................... 14-1

14.4 Customizing.......................................................................................................................... 14-2

14.5 Keywords.............................................................................................................................. 14-2

14.6 Log Records ......................................................................................................................... 14-2

ADVANCED MANAGEMENT ................................................................................................................... IV

Chapter 15 Filter Configuration........................................................................................................... 15-1

15.1 About Filtering ..................................................................................................................... 15-1

15.1.1 The Filter Structure of the ZyWALL................................................................................ 15-2

15.2 Configuring a Filter Set ........................................................................................................ 15-4

15.2.1 Filter Rules Summary Menu............................................................................................. 15-6

15.2.2 Configuring a Filter Rule.................................................................................................. 15-7

15.2.3 TCP/IP Filter Rule............................................................................................................ 15-7

15.2.4 Generic Filter Rule .........................................................................................................15-12

15.3 Example Filter ....................................................................................................................15-14

15.4 Filter Types and NAT......................................................................................................... 15-17

15.5 Firewall............................................................................................................................... 15-17

15.6 Applying a Filter and Factory Defaults ..............................................................................15-18

15.6.1 LAN traffic ..................................................................................................................... 15-18

15.6.2 Remote Node Filters....................................................................................................... 15-18

Chapter 16 SNMP Configuration ......................................................................................................... 16-1

16.1 About SNMP ........................................................................................................................ 16-1

16.2 Supported MIBs.................................................................................................................... 16-3

16.3 Configuring SNMP............................................................................................................... 16-3

16.4 SNMP Traps ......................................................................................................................... 16-4

Chapter 17 System Information & Diagnosis...................................................................................... 17-1

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17.1 System Status........................................................................................................................17-1

17.2 System Information and Console Port Speed........................................................................17-3

17.2.1 System Information...........................................................................................................17-4

17.2.2 Console Port Speed...........................................................................................................17-5

17.3 Log and Trace .......................................................................................................................17-5

17.3.1 Viewing Error Log............................................................................................................ 17-5

17.3.2 UNIX Syslog.....................................................................................................................17-7

17.3.3 Call-Triggering Packet.................................................................................................... 17-10

17.4 Diagnostic ...........................................................................................................................17-11

17.4.1 WAN DHCP ...................................................................................................................17-12

Chapter 18 Firmware and Configuration Maintenance .....................................................................18-1

18.1 Filename Conventions ..........................................................................................................18-1

18.2 Backup Configuration...........................................................................................................18-2

18.2.1 Backup Configuration....................................................................................................... 18-2

18.2.2 Using the FTP Command from the Command Line .........................................................18-3

18.2.3 Example of FTP Commands from the Command Line.....................................................18-3

18.2.4 GUI-Based FTP Clients ....................................................................................................18-4

18.2.5 TFTP and FTP over WAN Will Not Work When ............................................................18-4

18.2.6 Backup Configuration Using TFTP .................................................................................. 18-5

18.2.7 TFTP Command Example ................................................................................................18-5

18.2.8 GUI-Based TFTP Clients..................................................................................................18-6

18.2.9 Backup Via Console Port.................................................................................................. 18-6

18.3 Restore Configuration...........................................................................................................18-7

18.3.1 Restore Using FTP or TFTP .............................................................................................18-8

18.3.2 Procedure To Restore Using FTP .....................................................................................18-8

18.3.3 Restore Using FTP Session Example................................................................................18-9

18.3.4 Restore Via Console Port.................................................................................................. 18-9

18.4 Uploading Firmware and Configuration Files ....................................................................18-10

18.4.1 Firmware File Upload..................................................................................................... 18-11

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18.4.2 Configuration File Upload.............................................................................................. 18-11

18.4.3 FTP File Upload Command from the Command Line Example .................................... 18-12

18.4.4 FTP Session Example of Firmware File Upload ............................................................ 18-13

18.4.5 TFTP File Upload........................................................................................................... 18-13

18.4.6 TFTP Upload Command Example ................................................................................. 18-14

18.4.7 Uploading Via Console Port........................................................................................... 18-14

18.4.8 Uploading a Firmware File Via Console Port ................................................................ 18-14

18.4.9 Example Xmodem Firmware Upload Using HyperTerminal .........................................18-15

18.4.10 Uploading a Configuration File Via Console Port...................................................... 18-16

18.4.11 Example Xmodem Configuration Upload Using HyperTerminal .............................. 18-16

Chapter 19 System Maintenance & Information................................................................................ 19-1

19.1 Command Interpreter Mode ................................................................................................. 19-1

19.2 Call Control Support............................................................................................................. 19-2

19.2.1 Budget Management......................................................................................................... 19-2

19.2.2 Call History ...................................................................................................................... 19-4

19.3 Time and Date Setting .......................................................................................................... 19-5

19.3.1 Resetting the Time............................................................................................................ 19-7

Chapter 20 Remote Management......................................................................................................... 20-1

20.1 Telnet.................................................................................................................................... 20-1

20.2 FTP ....................................................................................................................................... 20-1

20.3 Web ...................................................................................................................................... 20-2

20.4 Remote Management............................................................................................................ 20-2

20.4.1 Remote Management Limitations..................................................................................... 20-3

20.5 Remote Management and NAT ............................................................................................ 20-4

20.6 System Timeout.................................................................................................................... 20-4

CALL SCHEDULING AND VPN/IPSEC .....................................................................................................V

Chapter 21 Call Scheduling................................................................................................................... 21-1

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21.1 Introduction........................................................................................................................... 21-1

Chapter 22 Introduction to IPSec.........................................................................................................22-1

22.1 Introduction........................................................................................................................... 22-1

22.1.1 VPN ..................................................................................................................................22-1

22.1.2 IPSec ................................................................................................................................. 22-1

22.1.3 Security Association ......................................................................................................... 22-1

22.1.4 Other Terminology ...........................................................................................................22-1

22.1.5 VPN Applications ............................................................................................................. 22-2

22.2 IPSec Architecture ................................................................................................................ 22-3

22.2.1 IPSec Algorithms..............................................................................................................22-4

22.2.2 Key Management..............................................................................................................22-4

22.3 Encapsulation........................................................................................................................22-5

22.3.1 Transport Mode.................................................................................................................22-5

22.3.2 Tunnel Mode.....................................................................................................................22-5

22.4 IPSec and NAT ..................................................................................................................... 22-5

Chapter 23 VPN/IPSec Setup................................................................................................................23-1

23.1 VPN/IPSec Setup .................................................................................................................. 23-1

23.2 IPSec Algorithms .................................................................................................................. 23-2

23.2.1 AH (Authentication Header) Protocol .............................................................................. 23-2

23.2.2 ESP (Encapsulating Security Payload) Protocol ............................................................... 23-2

23.3 IPSec Summary..................................................................................................................... 23-3

23.3.1 IPSec Setup....................................................................................................................... 23-7

23.4 IKE Setup............................................................................................................................ 23-10

23.4.1 IKE Phases......................................................................................................................23-10

23.4.2 Negotiation Mode ........................................................................................................... 23-11

23.4.3 Pre-Shared Key............................................................................................................... 23-12

23.4.4 Diffie-Hellman (DH) Key Groups .................................................................................. 23-12

23.4.5 Perfect Forward Secrecy (PFS)....................................................................................... 23-12

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23.5 Manual Setup...................................................................................................................... 23-15

23.5.1 Active Protocol............................................................................................................... 23-15

23.5.2 Security Parameter Index (SPI) ...................................................................................... 23-15

Chapter 24 SA Monitor ......................................................................................................................... 24-1

1.1. Introduction .............................................................................................................................. 24-1

Chapter 25 IPSec Log............................................................................................................................ 25-1

TROUBLESHOOTING, APPENDICES AND INDEX .............................................................................. VI

Chapter 26 Troubleshooting.................................................................................................................. 26-1

26.1 Problems Starting Up the ZyWALL..................................................................................... 26-1

26.2 Problems with the LAN Interface......................................................................................... 26-2

26.3 Problems with the WAN interface........................................................................................ 26-2

26.4 Problems with Internet Access ............................................................................................. 26-3

26.5 Problems with the Password................................................................................................. 26-3

26.6 Problems with Remote Management.................................................................................... 26-3

Appendix A The Big Picture.......................................................................................................................A

Appendix B PPPoE .....................................................................................................................................C

Appendix C PPTP ....................................................................................................................................... E

Appendix D Hardware Specifications ...................................................................................................... H

Appendix E Important Safety Instructions ...............................................................................................I

Appendix F Boot Commands .................................................................................................................... K

Appendix G Firewall CLI Commands .....................................................................................................M

Appendix H Power Adapter Specifications...............................................................................................R

Index.............................................................................................................................................................U

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List of Figures

Figure 1-1 Secure Internet Access via Cable .................................................................................................. 1-4

Figure 1-2 Secure Internet Access via DSL.................................................................................................... 1-4

Figure 1-3 VPN Application........................................................................................................................... 1-5

Figure 2-1 Front Panel.................................................................................................................................... 2-1

Figure 2-2 ZyWALL 50 Rear Panel and Connections .................................................................................... 2-3

Figure 3-1 Initial Screen................................................................................................................................. 3-1

Figure 3-2 Password Screen ........................................................................................................................... 3-2

Figure 3-3 ZyWALL Main Menu ................................................................................................................... 3-3

Figure 3-4 Getting Started and Advanced Applications SMT Menus............................................................. 3-5

Figure 3-5 Advanced Management SMT Menus............................................................................................ 3-6

Figure 3-6 IPSec VPN Configuration SMT Menus ........................................................................................ 3-7

Figure 3-7 Menu 23 — System Password...................................................................................................... 3-7

Figure 4-1 Configure Dynamic DNS..............................................................................................................4-2

Figure 4-2 Menu 2 — WAN Setup................................................................................................................. 4-4

Figure 5-1 Menu 3 — LAN Setup.................................................................................................................. 5-1

Figure 5-2 Menu 3.1 — LAN Port Filter Setup.............................................................................................. 5-1

Figure 5-3 Physical Network.......................................................................................................................... 5-5

Figure 5-4 Partitioned Logical Networks ....................................................................................................... 5-5

Figure 5-5 Menu 3 — TCP/IP and DHCP Setup ............................................................................................ 5-5

Figure 5-6 Menu 3.2 — TCP/IP and DHCP Ethernet Setup........................................................................... 5-6

Figure 5-7 Menu 3.2.1 — IP Alias Setup .......................................................................................................5-8

Figure 6-1 Menu 4 — Internet Access Setup (Ethernet) ................................................................................ 6-1

Figure 6-2 Internet Access Setup (PPTP) ....................................................................................................... 6-3

Figure 6-3 Internet Access Setup (PPPoE) ..................................................................................................... 6-4

Figure 4-1 Menu 11.1 — Remote Node Profile for Ethernet Encapsulation.................................................. 4-2

List Of Figures xix

P312 Broadband Security Gateway

Figure 4-2 Menu 11.1 — Remote Node Profile for PPPoE Encapsulation.................................................... 4-4

Figure 4-3 Menu 11.1 — Remote Node Profile for PPTP Encapsulation ...................................................... 4-6

Figure 4-4 Menu 11.3 — Remote Node Network Layer Options .................................................................. 4-7

Figure 4-5 Menu 11.3 — Remote Node Network Layer Options .................................................................. 4-9

Figure 4-6 Menu 11.5 — Remote Node Filter (Ethernet Encapsulation) ......................................................4-11

Figure 4-7 Menu 11.5 — Remote Node Filter (PPPoE or PPTP Encapsulation) ..........................................4-11

Figure 5-1 Example of Static Routing Topology............................................................................................ 5-1

Figure 5-2 Menu 12 — IP Static Route Setup................................................................................................ 5-2

Figure 5-3 Menu 12. 1 — Edit IP Static Route .............................................................................................. 5-2

Figure 6-1 How NAT Works .......................................................................................................................... 6-3

Figure 6-2 NAT Application With IP Alias .................................................................................................... 6-4

Figure 6-3 Menu 4 — Applying NAT for Internet Access ............................................................................. 6-6

Figure 6-4 Menu 11.3 — Applying NAT to the Remote Node....................................................................... 6-7

Figure 6-5 Menu 15 — NAT Setup................................................................................................................ 6-8

Figure 6-6 Menu 15.1 — Address Mapping Sets ........................................................................................... 6-8

Figure 6-7 Menu 15.1.255 — SUA Address Mapping Rules......................................................................... 6-9

Figure 6-8 Menu 15.1.1 — First Set ............................................................................................................ 6-10

Figure 6-9 Menu 15.1.1.1 — Editing/Configuring an Individual Rule in a Set ........................................... 6-12

Figure 6-10 Menu 15.2 — NAT Server Setup.............................................................................................. 6-15

Figure 6-11 Multiple Servers Behind NAT Example ................................................................................... 6-15

Figure 6-12 NAT Example 1 ........................................................................................................................ 6-16

Figure 6-13 Menu 4 — Internet Access & NAT Example ........................................................................... 6-16

Figure 6-14 NAT Example 2 ........................................................................................................................ 6-17

Figure 6-15 Menu 15.2 — Specifying an Inside Server............................................................................... 6-18

Figure 6-16 NAT Example 3 ........................................................................................................................ 6-19

Figure 6-17 Example 3: Menu 11.3.............................................................................................................. 6-20

Figure 6-18 Example 3: Menu 15.1.1.1........................................................................................................ 6-20

List Of Figures xx

ZyWALL 50 Internet Security Gateway

Figure 6-19 Example 3: Final Menu 15.1.1.................................................................................................. 6-21

Figure 6-20 Example 3: Menu 15.2.............................................................................................................. 6-21

Figure 6-21 NAT Example 4 ........................................................................................................................6-22

Figure 6-22 Example 4: Menu 15.1.1.1 — Address Mapping Rule ............................................................. 6-23

Figure 6-23 Example 4: Menu 15.1.1 — Address Mapping Rules............................................................... 6-23

Figure 7-1 ZyWALL Firewall Application ..................................................................................................... 7-3

Figure 7-2 Three-Way Handshake.................................................................................................................. 7-5

Figure 7-3 SYN Flood.................................................................................................................................... 7-5

Figure 7-4 Smurf Attack ................................................................................................................................. 7-6

Figure 7-5 Stateful Inspection ........................................................................................................................ 7-8

Figure 8-1 Menu 21 — Filter and Firewall Setup .......................................................................................... 8-1

Figure 8-2 Menu 21.2 — Firewall Setup........................................................................................................ 8-2

Figure 8-3 Example Firewall Log ..................................................................................................................8-2

Figure 9-1 Main Menu ................................................................................................................................... 9-2

Figure 9-2 Enabling the Firewall.................................................................................................................... 9-3

Figure 9-3 E-mail Screen................................................................................................................................ 9-4

Figure 9-4 E-mail Log.................................................................................................................................... 9-7

Figure 9-5 Attack Alert................................................................................................................................... 9-9

Figure 10-1 LAN to WAN Traffic ................................................................................................................10-3

Figure 10-2 WAN to LAN Traffic ................................................................................................................10-4

Figure 10-3 Firewall Rules Summary — First Screen ................................................................................. 10-5

Figure 10-4 Creating/Editing A Firewall Rule............................................................................................ 10-10

Figure 10-5 Adding/Editing Source and Destination Addresses................................................................. 10-12

Figure 10-6 Timeout Screen .......................................................................................................................10-14

Figure 11-1 Custom Ports............................................................................................................................. 11-1

Figure 11-2 Creating/Editing A Custom Port ............................................................................................... 11-3

Figure 12-1 Log Screen................................................................................................................................ 12-1

List Of Figures xxi

P312 Broadband Security Gateway

Figure 13-1 Activate the Firewall................................................................................................................. 13-2

Figure 13-2 Example 1: E-Mail Screen........................................................................................................ 13-3

Figure 13-3 Example 1: Configuring a Rule................................................................................................ 13-4

Figure 13-4 Example 1: Destination Address for Traffic Originating from the Internet .............................. 13-5

Figure 13-5 Example 1: Rule Summary Screen........................................................................................... 13-6

Figure 13-6 Send Alerts When Attacked...................................................................................................... 13-7

Figure 13-7 Configuring A POP Custom Port.............................................................................................. 13-8

Figure 13-8 Example 2: Local Network Rule 1 Configuration .................................................................... 13-9

Figure 13-9 Example 2: Local Network Rule Summary............................................................................ 13-10

Figure 13-10 Example: Internet to Local Network Rule Summary ............................................................13-11

Figure 13-11 Custom Port for Syslog......................................................................................................... 13-12

Figure 13-12 Syslog Rule Configuration ................................................................................................... 13-13

Figure 13-13 Example 3: Rule Summary................................................................................................... 13-14

Figure 15-1 Outgoing Packet Filtering Process ........................................................................................... 15-2

Figure 15-2 Filter Rule Process.................................................................................................................... 15-3

Figure 15-4 Menu 21 — Filter and Firewall Setup ...................................................................................... 15-4

Figure 15-5 Menu 21.1 — Filter Set Configuration..................................................................................... 15-4

Figure 15-6 NetBIOS_WAN Filter Rules Summary .................................................................................... 15-5

Figure 15-7 NetBIOS _LAN Filter Rules Summary.................................................................................... 15-5

Figure 15-8 Menu 21.1.1.1 — TCP/IP Filter Rule ....................................................................................... 15-8

Figure 15-9 Executing an IP Filter ..............................................................................................................15-11

Figure 15-10 Menu 21.4.1.1 — Generic Filter Rule.................................................................................. 15-12

Figure 15-11 Telnet Filter Example............................................................................................................ 15-14

Figure 15-12 Example Filter — Menu 21.1.3.1......................................................................................... 15-15

Figure 15-13 Example Filter Rules Summary — Menu 21.1.3.................................................................. 15-16

Figure 15-14 Protocol and Device Filter Sets ............................................................................................ 15-17

Figure 15-15 Filtering LAN Traffic ........................................................................................................... 15-18

List Of Figures xxii

ZyWALL 50 Internet Security Gateway

Figure 15-16 Filtering Remote Node Traffic.............................................................................................. 15-19

Figure 16-1 SNMP Management Model ......................................................................................................16-2

Figure 16-2 Menu 22 — SNMP Configuration ............................................................................................16-4

Figure 17-1 Menu 24 — System Maintenance............................................................................................. 17-1

Figure 17-2 Menu 24.1 — System Maintenance — Status .......................................................................... 17-2

Figure 17-3 Menu 24.2 — System Information and Console Port Speed .................................................... 17-4

Figure 17-4 Menu 24.2.1 — System Maintenance — Information............................................................. 17-4

Figure 17-5 Menu 24.2.2 — System Maintenance — Change Console Port Speed.................................... 17-5

Figure 17-6 Menu 24.3 — System Maintenance — Log and Trace ............................................................. 17-6

Figure 17-7 Examples of Error and Information Messages.......................................................................... 17-6

Figure 17-8 Menu 24.3.2 — System Maintenance — UNIX Syslog........................................................... 17-7

Figure 17-9 Call-Triggering Packet Example............................................................................................. 17-11

Figure 17-10 Menu 24.4 — System Maintenance — Diagnostic............................................................... 17-12

Figure 17-11 WAN & LAN DHCP.............................................................................................................17-13

Figure 18-1 Telnet in Menu 24.5 .................................................................................................................. 18-3

Figure 18-2 FTP Session Example ............................................................................................................... 18-4

Figure 18-3 System Maintenance — Backup Configuration........................................................................ 18-6

Figure 18-4 System Maintenance — Starting Xmodem Download Screen ................................................. 18-7

Figure 18-5 Backup Configuration Example................................................................................................ 18-7

Figure 18-6 Successful Backup Confirmation Screen.................................................................................. 18-7

Figure 18-7 Telnet into Menu 24.6 ............................................................................................................... 18-8

Figure 18-8 Restore Using FTP or TFTP Session Example ......................................................................... 18-9

Figure 18-9 System Maintenance — Restore Configuration........................................................................ 18-9

Figure 18-10 System Maintenance — Starting Xmodem Download Screen .............................................18-10

Figure 18-11 Restore Configuration Example............................................................................................ 18-10

Figure 18-12 Successful Restoration Confirmation Screen........................................................................ 18-10

Figure 18-13 Telnet Into Menu 24.7.1 — Upload System Firmware......................................................... 18-11

List Of Figures xxiii

P312 Broadband Security Gateway

Figure 18-14 Telnet Into Menu 24.7.2 — System Maintenance ................................................................ 18-12

Figure 18-15 FTP Session Example of Firmware File Upload .................................................................. 18-13

Figure 18-16 Menu 24.7.1 as seen using the Console Port ........................................................................ 18-15

Figure 18-17 Example Xmodem Upload ................................................................................................... 18-15

Figure 18-18 Menu 24.7.2 as seen using the Console Port ........................................................................ 18-16

Figure 18-19 Example Xmodem Upload ................................................................................................... 18-17

Figure 19-1 Command Mode in Menu 24.................................................................................................... 19-1

Figure 19-2 Valid Commands ...................................................................................................................... 19-2

Figure 19-3 Call Control .............................................................................................................................. 19-2

Figure 19-4 Budget Management................................................................................................................. 19-3

Figure 19-5 Call History .............................................................................................................................. 19-4

Figure 19-6 Menu 24 — System Maintenance............................................................................................. 19-5

Figure 19-7 Menu 24.10 System Maintenance — Time and Date Setting................................................... 19-6

Figure 20-1 Telnet Configuration on a TCP/IP Network.............................................................................. 20-1

Figure 20-2 Menu 24.11 – Remote Management Control............................................................................ 20-2

Figure 21-1 Menu 26 - Schedule Setup........................................................................................................ 21-1

Figure 21-2 Schedule Set Setup ................................................................................................................... 21-2

Figure 21-3 Applying Schedule Set(s) to a Remote Node (PPPoE)............................................................. 21-4

Figure 21-4 Applying Schedule Set(s) to a Remote Node (PPTP)............................................................... 21-4

Figure 22-1 Encryption and Decryption....................................................................................................... 22-2

Figure 22-2 VPN Application ...................................................................................................................... 22-3

Figure 22-3 IPSec Architecture .................................................................................................................... 22-4

Figure 22-4 Transport and Tunnel Mode IPSec Encapsulation .................................................................... 22-5

Figure 23-1 VPN SMT Menu Tree............................................................................................................... 23-1

Figure 23-2 Menu 27 — VPN/IPSec Setup ................................................................................................. 23-2

Figure 23-3 IPSec Summary Fields ............................................................................................................. 23-3

Figure 23-4 Telecommuter’s ZyWALL Configuration................................................................................. 23-4

List Of Figures xxiv

ZyWALL 50 Internet Security Gateway

Figure 23-5 HQ ZyWALL Configuration..................................................................................................... 23-5

Figure 23-6 Menu 27.1 — IPSec Summary ................................................................................................. 23-5

Figure 23-7 Menu 27.1.1 — IPSec Setup..................................................................................................... 23-8

Figure 23-8 Two Phases to set up the IPSec SA......................................................................................... 23-11

Figure 23-9 Menu 27.1.1.1 — IKE Setup....................................................................................................... 23-13

Figure 23-10 Menu 27.1.1.2 — Manual Setup........................................................................................... 23-16

Figure 24-1 Menu 27.2 — SA Monitor ........................................................................................................ 24-1

Figure 25-1 Example VPN Initiator IPSec Log............................................................................................ 25-1

Figure 25-2 Example VPN Responder IPSec Log........................................................................................25-1

List Of Figures xxv

ZyWALL 50 Internet Security Gateway

List Of Tables

Table 2-1 LED Descriptions ........................................................................................................................... 2-1

Table 3-1 Main Menu Commands .................................................................................................................. 3-2

Table 3-2 Main Menu Summary.....................................................................................................................3-3

Table 4-1 Configure Dynamic DNS Menu Fields .......................................................................................... 4-2

Table 4-2 WAN Setup Menu Fields................................................................................................................4-4

Table 5-1 Example of Network Properties for LAN Servers with Fixed IP Addresses .................................. 5-2

Table 5-2 Private IP Address Ranges.............................................................................................................. 5-3

Table 5-3 DHCP Ethernet Setup Menu Fields................................................................................................ 5-6

Table 5-4 LAN TCP/IP Setup Menu Fields.................................................................................................... 5-7

Table 5-5 IP Alias Setup Menu Fields ............................................................................................................5-8

Table 6-1 Internet Access Setup Menu Fields ................................................................................................6-1

Table 6-2 New Fields in Menu 4 (PPTP) screen ............................................................................................6-3

Table 6-3 New Fields in Menu 4 (PPPoE) screen ..........................................................................................6-4

Table 4-1 Fields in Menu 11.1........................................................................................................................4-2

Table 4-2 Fields in Menu 11.1 (PPPoE Encapsulation Specific)....................................................................4-5

Table 4-3 Fields in Menu 11.1 (PPTP Encapsulation)....................................................................................4-6

Table 4-4 Remote Node Network Layer Options Menu Fields ...................................................................... 4-7

Table 4-5 Remote Node Network Layer Options Menu Fields ...................................................................... 4-9

Table 5-1 IP Static Route Menu Fields........................................................................................................... 5-3

Table 6-1 NAT Definitions .............................................................................................................................6-1

Table 6-2 NAT Mapping Types ......................................................................................................................6-5

xxvi List of Tables

ZyWALL 50 Internet Security Gateway

Table 6-3 Applying NAT in Menus 4 & 11.3 ................................................................................................. 6-7

Table 6-4 SUA Address Mapping Rules ........................................................................................................ 6-9

Table 6-5 Fields in Menu 15.1.1 ...................................................................................................................6-11

Table 6-6 Menu 15.1.1.1 — Editing/Configuring an Individual Rule in a Set ............................................ 6-12

Table 6-7 Services & Port Numbers ............................................................................................................ 6-13

Table 7-1 Common IP Ports........................................................................................................................... 7-4

Table 7-2 ICMP Commands That Trigger Alerts........................................................................................... 7-6

Table 7-3 Legal NetBIOS Commands ........................................................................................................... 7-7

Table 7-4 Legal SMTP Commands................................................................................................................ 7-7

Table 8-1 View Firewall Log ......................................................................................................................... 8-2

Table 9-1 E-mail ............................................................................................................................................ 9-5

Table 9-2 SMTP Error Messages................................................................................................................... 9-6

Table 9-3 Attack Alert.................................................................................................................................... 9-9

Table 10-1 Firewall Rules Summary — First Screen .................................................................................. 10-5

Table 10-2 Predefined Services ................................................................................................................... 10-7

Table 10-3 Creating/Editing A Firewall Rule ............................................................................................ 10-10

Table 10-4 Adding/Editing Source and Destination Addresses ................................................................. 10-13

Table 10-5 Timeout Menu ......................................................................................................................... 10-15

Table 11-1 Custom Ports...............................................................................................................................11-2

Table 11-2 Creating/Editing A Custom Port .................................................................................................11-4

Table 12-1 Log Screen................................................................................................................................. 12-2

Table 15-1 Abbreviations Used in the Filter Rules Summary Menu ........................................................... 15-6

Table 15-2 Rule Abbreviations Used........................................................................................................... 15-6

List of Tables xxvii

ZyWALL 50 Internet Security Gateway

Table 15-3 TCP/IP Filter Rule Menu Fields.................................................................................................15-8

Table 15-4 Generic Filter Rule Menu Fields ..............................................................................................15-13

Table 16-1 General SNMP Commands ........................................................................................................16-3

Table 16-2 SNMP Configuration Menu Fields............................................................................................. 16-4

Table 16-3 SNMP Traps ...............................................................................................................................16-5

Table 17-1 System Maintenance — Status Menu Fields .............................................................................. 17-2

Table 17-2 Fields in System Maintenance — Information...........................................................................17-4

Table 17-3 System Maintenance Menu Syslog Parameters..........................................................................17-7

Table 17-4 System Maintenance Menu Diagnostic ....................................................................................17-13

Table 18-1 Filename Conventions................................................................................................................18-2

Table 18-2 General Commands for GUI-Based FTP Clients .......................................................................18-4

Table 18-3 General Commands for GUI-Based TFTP Clients.....................................................................18-6

Table 19-1 Budget Management ..................................................................................................................19-3

Table 19-2 Call History Fields .....................................................................................................................19-4

Table 19-3 Time and Date Setting Fields ..................................................................................................... 19-6

Table 20-1 Menu 24.11 – Remote Management Control .............................................................................20-3

Table 21-1 Schedule Set Setup Fields ..........................................................................................................21-2

Table 22-1 VPN and NAT ............................................................................................................................22-6

Table 23-1 AH and ESP................................................................................................................................23-3

Table 23-2 Telecommuter and HQ Configuration Example .........................................................................23-4

Table 23-3 Menu 27.1 — IPSec Summary...................................................................................................23-6

Table 23-4 Menu 27.1.1 — IPSec Setup ......................................................................................................23-8

Table 23-5 Menu 27.1.1.1 — IKE Setup ........................................................................................................ 23-13

xxviii List of Tables

ZyWALL 50 Internet Security Gateway

Table 23-6 Active Protocol — Encapsulation and Security Protocol ........................................................ 23-15

Table 23-7 Menu 27.1.1.2 — Manual Setup.............................................................................................. 23-16

Table 24-1 Menu 27.2 — SA Monitor......................................................................................................... 24-1

Table 25-1 Sample IKE Key Exchange Logs .............................................................................................. 25-2

Table 25-2 Sample IPSec Logs During Packet Transmission...................................................................... 25-3

Table 25-3 RFC-2408 ISAKMP Payload Types .......................................................................................... 25-4

Table 26-1 Troubleshooting the Start-Up of your ZyWALL........................................................................ 26-1

Table 26-2 Troubleshooting the LAN Interface........................................................................................... 26-2

Table 26-3 Troubleshooting the WAN interface .......................................................................................... 26-2

Table 26-4 Troubleshooting Internet Access................................................................................................ 26-3

Table 26-5 Troubleshooting the Password................................................................................................... 26-3

Table 26-6 Troubleshooting Remote Management...................................................................................... 26-4

List of Tables xxix

ZyWALL 50 Internet Security Gateway

Preface

About Your ZyWALL

Congratulations on your purchase of the ZyWALL 50 Internet Security Gateway.

Don’t forget to register your ZyWALL (fast, easy online registration at www.zyxel.com)

The ZyWALL 50 is a dual Ethernet Internet Security Gateway integrated with robust firewall solutions and
network management features that allows access to the Internet via cable/ADSL modem or Internet router. It
is designed for:

 Home offices and small businesses with cable, xDSL and wireless modem via Ethernet port as Internet

access media.

 Multiple office/department connections via access devices.
 E-commerce/EDI applications.

The ZyWALL 50 features an ICSA certified firewall, IPSec VPN capability (allowing up to 50 simultaneous
secure connections), MultiNAT (for multiple IP address translation), web page content filtering and an
embedded web server for easy configuration. See the next chapter for more details on these and other
features.

The embedded web configurator is an all-platform web-based utility that allows you to easily access the
ZyWALLs’ management settings and configure the firewall. There is an embedded web help (click the Help
button) for the configurator as well as more comprehensive HTML help on the accompanying CD.
Most functions of the ZyWALL are also software configurable via the SMT (System Management Terminal)
interface. The SMT is a menu-driven interface that you can access from a terminal emulator through the
console port or over a telnet connection.

You can configure most features of the ZyWALL 50 via SMT but we recommend you

for free future product updates and information.

configure the firewall using the ZyWALL Web Configurator.

About This User's Manual

This manual is designed to guide you through the SMT configuration of your ZyWALL 50 for its various
applications. There is also HTML help for the embedded web configurator.

Related Documentation

 Supporting Disk

More detailed information about the ZyWALL and examples of its use can be found in our included
disk (as well as on the zyxel.com web site). This disk contains information on configuring your
ZyWALL for Internet Access, a general FAQ, an advanced FAQ, Application Notes,
Troubleshooting, a reference for CI Commands as well as bundled software.

 Quick Start Guide

Preface xxxi

ZyWALL 50 Internet Security Gateway

Our Quick Start Guide is designed to help you get your ZyWALL up and running right away. It
contains a detailed easy-to-follow connection diagram, ZyWALL default settings, handy checklists,
information on setting up your network and information on configuring your ZyWALL for Internet
access.

 Packing List Card

Finally, you should have a Packing List Card, which lists all items that should have come with your
ZyWALL.

 Glossary

Please refer to www.zyxel.com

 ZyXEL Web Site

The ZyXEL download library at www.zyxel.com

Syntax Conventions

 “Enter” means for you to type one or more characters and press the carriage return. “Select” or

“Choose” means for you to make a selection from one of the predefined choices.

 The SMT menu titles and labels are in Bold Times font. The choices of a menu item are in Bold

Arial font. A single keystroke is in Arial font and enclosed in square brackets, for instance,

[ENTER] means the Enter, or carriage return, key; [ESC] means the escape key and [SPACE BAR]
means the space bar. [UP] and [DOWN] are the up and down arrow keys.

 For brevity’s sake, we will use “e.g.” as a shorthand for “for instance” and “i.e.” for “that is” or “in

other words” throughout this manual.

The ZyWALL 50 may be referred to simply as the ZyWALL throughout this manual.

for an online glossary of networking terms.

contains additional support documentation.

xxxii Preface

Getting Started

Part I:

Getting Started

This part is structured as a step-by-step guide to help you connect, install and setup your ZyWALL

to operate on your network and access the Internet.

I

ZyWALL 50 Internet Security Gateway

Chapter 1

Getting to Know Your ZyWALL

This chapter introduces the main features and applications of the ZyWALL.

1.1 The ZyWALL 50 Internet Security Gateway

The ZyWALL 50 is a dual Ethernet Internet security gateway integrated with a robust firewall and network
management features designed for home offices and small businesses to access the Internet via cable/ADSL
modem or Internet router.
By integrating NAT, firewall and VPN capability, ZyXEL’s ZyWALL 50 provides not only ease of
installation and Internet access, but also a complete security solution that protects your Intranet and
efficiently manages data traffic on your network.
The ZyWALL web configurator is a breeze to operate and totally independent of the operating system
platform you use.

1.2 Features of The ZyWALL 50

The following are the main features of the ZyWALL 50.

Auto-negotiating 10/100Mbps Ethernet LAN

This auto-negotiation feature allows the ZyWALL to detect the speed of incoming transmissions and adjust
appropriately without manual intervention. It allows data transfer of either 10 Mbps or 100 Mbps in either
half-duplex or full-duplex mode depending on your Ethernet network.

IPSec VPN Capability

Establish a Virtual Private Network (VPN) to connect with business partners and branch offices using data
encryption and the Internet to provide secure communications without the expense of leased site-to-site lines.
The ZyWALL 50 VPN is based on the IPSec standard and is fully interoperable with other IPSec-based VPN
products. The ZyWALL 50 supports up to 50 runtime SAs (Security Associations).

Firewall

The ZyWALL is a stateful inspection firewall with DoS (Denial of Service) protection. By default, when the
firewall is activated, all incoming traffic from the WAN to the LAN is blocked unless it is initiated from the
LAN. The ZyWALL firewall supports TCP/UDP inspection, DoS detection and prevention, real time alerts,
reports and logs.

Getting to Know Your ZyWALL 1-1

ZyWALL 50 Internet Security Gateway

You can configure most features of the ZyWALL 50 via SMT but we recommend

you configure the firewall and Content Filters using the ZyWALL web configurator.

Content Filtering

The ZyWALL can block web features such as ActiveX controls, Java applets and cookies, as well as disable
web proxies. The ZyWALL can also block specific URLs by using the keyword feature.

Packet Filtering

The Packet Filtering mechanism blocks unwanted traffic from entering/leaving your network.

Call Scheduling

Configure call time periods to restrict and allow access for users on remote nodes.

PPPoE

PPPoE facilitates the interaction of a host with an Internet modem to achieve access to high-speed data
networks via a familiar "dial-up networking" user interface.

PPTP Encapsulation

Point-to-Point Tunneling Protocol (PPTP) is a network protocol that enables secure transfer of data from a
remote client to a private server, creating a Virtual Private Network (VPN) using a TCP/IP-based network.
PPTP supports on-demand, multi-protocol and virtual private networking over public networks, such as the
Internet. The ZyWALL supports one PPTP server connection at any given time.

Dynamic DNS Support

With Dynamic DNS support, you can have a static hostname alias for a dynamic IP address, allowing the
host to be more easily accessible from various locations on the Internet. You must register for this service
with a Dynamic DNS client to use this service.

IP Multicast

Deliver IP packets to a specific group of hosts (only) using IP multicast. IGMP (Internet Group Management
Protocol) is the protocol used to support multicast groups. The latest version is version 2 (see RFC 2236); the
ZyWALL supports both versions 1 and 2.

IP Alias

IP Alias allows you to partition a physical network into logical networks over the same Ethernet interface.
The ZyWALL supports three logical LAN interfaces via its single physical Ethernet interface with the
ZyWALL itself as the gateway for each LAN network.

SNMP

SNMP (Simple Network Management Protocol) is a protocol used for exchanging management information
between network devices. SNMP is a member of the TCP/IP protocol suite. Your ZyWALL supports SNMP
agent functionality, which allows a manager station to manage and monitor the ZyWALL through the
network. The ZyWALL supports SNMP version one (SNMPv1).

1-2 Getting to Know Your ZyWALL

ZyWALL 50 Internet Security Gateway

Network Address Translation (NAT)

NAT (Network Address Translation - NAT, RFC 1631) allows the translation of an Internet Protocol address
used within one network to a different IP address known within another network.

Port Forwarding

Use this feature to forward incoming service requests to a server on your local network. You may enter a
single port number or a range of port numbers to be forwarded, and the local IP address of the desired server.

DHCP (Dynamic Host Configuration Protocol)

DHCP (Dynamic Host Configuration Protocol) allows the individual clients (workstations) to obtain the
TCP/IP configuration at start-up from a centralized DHCP server. The ZyWALL has built-in DHCP server
capability, enabled by default, which means it can assign IP addresses, an IP default gateway and DNS
servers to Windows 9X, Windows NT and other systems that support the DHCP client. The ZyWALL can
now also act as a surrogate DHCP server (DHCP Relay) where it relays IP address assignment from the
actual real DHCP server to the clients.

Full Network Management

This feature allows you to access the SMT (System Management Terminal) through the console port or telnet
connection.

RoadRunner Support

In addition to standard cable modem services, the ZyWALL supports Time Warner’s RoadRunner Service.

Time and Date Setting

This new feature (Menu 24.10) allows you to get the current time and date from an external server when you
power up your ZyWALL. The real time is then displayed in the ZyWALL error logs and firewall logs. If you
do not choose a time service protocol that your timeserver will send when the ZyWALL powers up, you can
enter the time manually but each time the system is booted, the time and date will be reset to
2000/01/0100:00:00.

Logging and Tracing

♦ Built-in message logging and packet tracing.
♦ Unix syslog facility support.

Upgrade ZyWALL Firmware via LAN

The firmware of the ZyWALL 50 can be upgraded via the LAN.

Embedded FTP and TFTP Servers

The ZyWALL’s embedded FTP and TFTP Servers enable fast firmware upgrades as well as configuration
file backups and restoration.

Getting to Know Your ZyWALL 1-3

ZyWALL 50 Internet Security Gateway

1.3 Applications for the ZyWALL 50

1.3.1 Secure Broadband Internet Access via Cable or DSL Modem

A cable modem or xDSL modem can connect to the ZyWALL 50 for broadband Internet access via Ethernet
port on the modem. It provides not only high speed Internet access, but secured internal network protection
and management as well.

Figure 1-1 Secure Internet Access via Cable

Figure 1-2 Secure Internet Access via DSL

You can also use your xDSL modem in the bridge mode for always-on Internet access and high-speed data
transfer.

1-4 Getting to Know Your ZyWALL

ZyWALL 50 Internet Security Gateway

1.3.2 VPN Application

ZyWALL VPN is an ideal cost-effective way to connect branch offices and business partners over the
Internet without the need (and expense) for leased lines between sites.

Figure 1-3 VPN Application

Getting to Know Your ZyWALL 1-5

ZyWALL 50 Internet Security Gateway

Chapter 2

Hardware Installation

This chapter explains the LEDs and ports as well as how to connect the hardware and perform

the initial setup.

2.1 Front Panel LEDs and Back Panel Ports

2.1.1 Front Panel LEDs

The LEDs on the front panel indicate the operational status of the ZyWALL.

Figure 2-1 Front Panel

The following table describes LED functions.

Table 2-1 LED Descriptions

LED FUNCTION COLOR STATUS MEANING

PWR Power Green On The ZyWALL is turned on.

Off The ZyWALL is turned off.

SYS System

Green Off The 10M LAN is not connected. 10M LAN LAN

On The ZyWALL is connected to a 10M LAN.

Hardware Installation 2-1

Off The system is not ready or failed.

On The system is ready and running.

Flashing The system is rebooting.

ZyWALL 50 Internet Security Gateway

Table 2-1 LED Descriptions

LED FUNCTION COLOR STATUS MEANING

Flashing The 10M LAN is sending/receiving packets.

100M
LAN

10M
WAN

100M
WAN

LAN Orange

WAN Green

WAN Orange

Off The 100M LAN is not connected.

On The ZyWALL is connected to a 100Mbps LAN.

Flashing The 100M LAN is sending/receiving packets.

Off The 10M WAN is not connected.

On The ZyWALL is connected to a 10M WAN.

Flashing The 10M WAN is sending/receiving packets.

Off The WAN Link is not ready, or has failed.

On The WAN Link is OK.

Flashing The 100M WAN link is sending/receiving packets.

2.2 ZyWALL 50 Rear Panel and Connections

The following figure shows the rear panel of your ZyWALL 50 and the related connections.

2-2 Hardware Installation

ZyWALL 50 Internet Security Gateway

Figure 2-2 ZyWALL 50 Rear Panel and Connections

This section outlines how to connect your ZyWALL 50 to the LAN and the WAN. If you want to connect a

cable modem you must connect the coaxial cable from your cable service to the threaded coaxial cable

connector on the back of the cable modem. Connect an xDSL modem to the xDSL wall jack. See also the

Appendices for important safety instructions when making connections to the ZyWALL.

Step 1. Connecting the Console Port

Use terminal emulator software on a computer when connecting a computer to the ZyWALL via the

console port. Connect the 9-pin end of the console cable to the console port of the ZyWALL and the other

end (choice of 9-pin or 25-pin, depending on your computer) to a serial port (COM1, COM2 or other COM

Hardware Installation 2-3

ZyWALL 50 Internet Security Gateway

port) of your computer. You can use an extension RS-232 cable if the enclosed one is too short. After the

initial setup, you can modify the configuration remotely through telnet connections.

Step 2. Connecting the ZyWALL to the Broadband Modem

Step 2a. Connecting the ZyWALL to the cable modem:

Connect the WAN port on the ZyWALL to the Ethernet port on the cable modem using

the cable that came with your cable modem. The Ethernet port on a cable modem is

sometimes labeled "PC" or "Workstation".

OR

Step 2b. Connecting the ZyWALL to the xDSL modem:

Connect the WAN port on the ZyWALL to the Ethernet port on the xDSL modem using

the cable that came with your xDSL modem.

Step 3. Connecting the ZyWALL to the LAN

For a single computer, connect the 10/100M LAN port on the ZyWALL to the Network Adapter on the

computer using the white straight-through cable and push in the Uplink button ("on"). If the Uplink button

is not “on”, you must use a crossover cable for this connection.

If you have more than one computer, then you must use an external hub. Connect the 10/100M LAN port

on the ZyWALL to a port on the hub using a straight-through Ethernet cable and make sure the Uplink

button is "off".

Step 4. Connecting the Power Adapter to your ZyWALL

Connect one end of the power adapter to the port labeled POWER on the rear panel of your ZyWALL.

Caution: To prevent damage to the ZyWALL, first make sure you have the correct

AC power adapter. See the Power Adapter Specification Appendix for regional

specifications.

Step 5. Grounding the ZyWALL

To ground the ZyWALL, connect a grounded wire to the F.G. (Frame Ground) of the ZyWALL.

2-4 Hardware Installation

ZyWALL 50 Internet Security Gateway

2.3 Additional Installation Requirements

In addition to the contents of your package, there are other hardware and software requirements you need

before you can install and use your ZyWALL. These requirements include:

1. A computer with an Ethernet NIC (Network Interface Card) installed.

2. A computer equipped with communications software configured to the following parameters:

♦ VT100 terminal emulation.

♦ 9600 Baud.

♦ No parity, 8 data bits, 1 stop bit, flow control set to none.

3. A cable/xDSL modem and an ISP account.

After the ZyWALL is properly set up, you can make future changes to the configuration through telnet or

web connections.

To keep the ZyWALL operating at optimal internal temperature, keep the bottom,

sides and rear clear of obstructions and away from the exhaust of other

equipment.

Hardware Installation 2-5

ZyWALL 50 Internet Security Gateway

Chapter 3

Initial Setup

This chapter explains how to perform initial ZyWALL setup and gives an overview of SMT menus.

3.1 Turning On Your ZyWALL

At this point, you should have connected the console port, the LAN port, the WAN port and the power port

to the appropriate devices or lines. Plug the power adapter into a wall outlet. The PWR LED should turn on.

The SYS LED will turn on after the system tests are complete. The WAN LED and one of the LAN LEDs

should turn on immediately after the SYS LED turns on, if connections have been made to the LAN and

WAN ports.

3.1.1 Initial Screen

When you turn on your ZyWALL, it performs several internal tests as well as line initialization.

After the tests, the ZyWALL asks you to press

[ENTER] to continue, as shown next.

Copyright (c) 1994 - 2001 ZyXEL Communications Corp.
initialize ch =0, ethernet address: 00:a0:c5:41:51:61
initialize ch =1, ethernet address: 00:a0:c5:41:51:62
Press ENTER to continue...

Figure 3-1 Initial Screen

3.1.2 Entering the Password

The login screen appears after you press [ENTER], prompting you to enter the password, as shown below.

For your first login, enter the default password “1234”. As you type the password, the screen displays an

(X) for each character you type.

Please note that if there is no activity for longer than five minutes after you log in, your ZyWALL will

automatically log you out and will display a blank screen. If you see a blank screen, press [ENTER] to

bring up the login screen again.

Initial Setup 3-1

ZyWALL 50 Internet Security Gateway

Enter Password : XXXX

Figure 3-2 Password Screen

3.2 Navigating the SMT Interface

The SMT (System Management Terminal) is the interface that you use to configure your ZyWALL.

Several operations that you should be familiar with before you attempt to modify the configuration are

listed in the table below.

Table 3-1 Main Menu Commands

OPERATION KEYSTROKE DESCRIPTION

Move down to
another menu

Move up to a
previous menu

Move to a “hidden”
menu

Move the cursor [ENTER] or

Entering
information

Required fields

N/A fields <N/A> Some of the fields in the SMT will show a <N/A>. This symbol

Save your
configuration

Exit the SMT Type 99, then press

[ENTER] To move forward to a submenu, type in the number of the desired

submenu and press [ENTER].

[ESC] Press [ESC] to move back to the previous menu.

Press [SPACE
BAR] to change No
to Yes then press
[ENTER].

[UP]/[DOWN] arrow
keys.

Type in or press
[SPACE BAR], then
press [ENTER].

<

?>

[ENTER] Save your configuration by pressing [ENTER] at the message

[ENTER].

Fields beginning with “Edit” lead to hidden menus and have a
default setting of No. Press [SPACE BAR] once to change No to
Yes, then press [ENTER] to go to the “hidden” menu.

Within a menu, press [ENTER] to move to the next field. You can
also use the [UP]/[DOWN] arrow keys to move to the previous
and the next field, respectively.

You need to fill in two types of fields. The first requires you to type
in the appropriate information. The second allows you to cycle
through the available choices by pressing [SPACE BAR].

All fields with the symbol <?> must be filled in order to be able to
save the new configuration.

refers to an option that is Not Applicable.

“Press ENTER to confirm or ESC to cancel”. Saving the data on
the screen will take you, in most cases to the previous menu.

Type 99 at the main menu prompt and press [ENTER] to exit the
SMT interface.

3-2 Initial Setup

ZyWALL 50 Internet Security Gateway

3.2.1 Main Menu

After you enter the password, the SMT displays the ZyWALL Main Menu, as shown next.

Copyright (c) 1994 - 2001 ZyXEL Communications Corp.

ZyWALL Main Menu

Getting Started Advanced Management

1. General Setup

2. WAN Setup

3. LAN Setup

4. Internet Access Setup

Advanced Applications

11. Remote Node Setup

12. Static Routing Setup

15. NAT Setup

Enter Menu Selection Number:

21. Filter and Firewall Setup

22. SNMP Configuration

23. System Password

24. System Maintenance

26. Schedule Setup

27. VPN/IPSec Setup

99. Exit

Figure 3-3 ZyWALL Main Menu

3.2.2 System Management Terminal Interface Summary

Table 3-2 Main Menu Summary

NO. MENU TITLE FUNCTION

1 General Setup Use this menu to set up administrative information and dynamic DNS.

2 WAN Setup Use this menu to clone a MAC address from a computer on your LAN.

3 LAN Setup Use this menu to configure LAN DHCP and TCP/IP settings as well as

apply LAN filters.

4 Internet Access Setup Configure your Internet Access setup (Internet address, gateway, login,

etc.) with this menu.

11 Remote Node Setup Use this menu to configure detailed remote node settings (your ISP is

also a remote node) as well as apply WAN filters.

12 Static Routing Setup Configure IP static routes in this menu.

15 NAT Setup Use this menu to configure Network Address Translation.

21 Filter and Firewall Setup Configure filters, activate/deactivate the firewall and view the firewall log.

22 SNMP Configuration Use this menu to configure SNMP-related parameters.

Initial Setup 3-3

ZyWALL 50 Internet Security Gateway

Table 3-2 Main Menu Summary

NO. MENU TITLE FUNCTION

23 System Password Change your password in this menu (recommended).

24 System Maintenance From displaying system status to uploading firmware, this menu provides

comprehensive system maintenance.

26 Schedule Setup Use this menu to schedule outgoing calls.

27 VPN/ IPSec Setup Use this menu to configure VPN connections.

99 Exit Use this menu to exit (necessary for remote configuration).

3-4 Initial Setup

ZyWALL 50 Internet Security Gateway

3.2.3 SMT Menus at a Glance

Figure 3-4 Getting Started and Advanced Applications SMT Menus

Initial Setup 3-5

ZyWALL 50 Internet Security Gateway

Figure 3-5 Advanced Management SMT Menus

3-6 Initial Setup

ZyWALL 50 Internet Security Gateway

Figure 3-6 IPSec VPN Configuration SMT Menus

3.3 Changing the System Password

The first thing you should do is change the default system password by following the steps shown next.

Step 1. Enter 23 in the main menu to open Menu 23 - System Password as shown below.

Menu 23 - System Password

Old Password= ?
New Password= ?
Retype to confirm= ?

Enter here to CONFIRM or ESC to CANCEL:

Figure 3-7 Menu 23 — System Password

Step 2. Type in your existing password and press [ENTER].

Step 3. Type in your new system password and press [ENTER].

Initial Setup 3-7

ZyWALL 50 Internet Security Gateway

Step 4. Re-type your new system password for confirmation and press [ENTER].

Note that as you type a password, the screen displays an (X) for each character you type.

3.4 Resetting the ZyWALL

If you forget your password or cannot access the ZyWALL, you will need to reload the factory-default

configuration file. Uploading this configuration file replaces the current configuration file with the factory-

default configuration file. This means that you will lose all configurations that you had previously and the

speed of the console port will be reset to the default of 9600bps with 8 data bit, no parity, one stop bit and

flow control set to none. The password will be reset to “1234” and the LAN IP address to 192.168.1.1also.

To obtain the default configuration file, download it from the ZyXEL FTP site, unzip it and save it in a

folder. Turn the ZyWALL off and then on to begin a session. When you turn on the ZyWALL again you

will see the initial screen. When you see the message “Press any key to enter Debug Mode within 3

seconds” press any key to enter debug mode.

To upload the configuration file, do the following:

1. Type atlc after the Enter Debug Mode message.

2. Wait for the Starting XMODEM upload message before activating XMODEM upload on your

terminal.

3. After a successful firmware upload, type atgo to restart the ZyWALL.

The ZyWALL is now reinitialized with a default configuration file including the default password of

“1234”.

3.4.1 Methods of Restoring Factory-Defaults

You can erase the current configuration and restore factory defaults in three ways:

1. Upload the default configuration file via the console port as described above. See later in this

User’s Guide for more information on how to transfer the configuration file to your ZyWALL

using the SMT menus.

2. Use the RESET button on the rear panel of the ZyWALL (see the next section). Use this method

for cases when the password or IP address of the ZyWALL is not known.

3. Use the web configurator to restore defaults (see the web configurator HTML help).

3-8 Initial Setup

ZyWALL 50 Internet Security Gateway

3.4.2 Procedure To Use The Reset Button

Make sure the SYS led is on (not blinking) before you begin this procedure.

1. Press the RESET button for ten seconds, then release it. If the SYS LED begins to blink, the

defaults have been restored and the ZyWALL restarts. Otherwise, go to step 2.

2. Turn the ZyWALL off.

3. While pressing the RESET button, turn the ZyWALL on.

4. Continue to hold the RESET button. The SYS LED will begin to blink and flicker very quickly

after about 10 or 15 seconds. This indicates that the defaults have been restored and the ZyWALL

is now restarting.

5. Release the RESET button and wait for the ZyWALL to finish restarting.

Initial Setup 3-9

ZyWALL 50 Internet Security Gateway

Chapter 4

General And WAN Setup

Menu 1 - General Setup contains administrative and system-related information. Clone a LAN

computer MAC address in the Menu 2 - WAN Setup.

4.1 System Name

System Name is for identification purposes. ZyXEL recommends you enter your computer’s “Computer

name”.

• In Windows 95/98 click Start -> Settings -> Control Panel and then double-click Network. Click the

Identification tab, note the entry for the Computer name field and enter it as the ZyWALL System

Name.

• In Windows 2000 click Start->Settings->Control Panel and then double-click System. Click the

Network Identification tab and then the Properties button. Note the entry for the Computer name

field and enter it as the ZyWALL System Name.

The Domain Name entry is what is propagated to the DHCP clients on the LAN. If you leave this field

blank, the domain name obtained by DHCP from the ISP is used. While you must enter the host name

(System Name) on each individual computer, the domain name can be assigned from the ZyWALL via

DHCP.

4.2 Dynamic DNS

Dynamic DNS (Domain Name System) allows you to update your current dynamic IP address with one or

many dynamic DNS services so that anyone can contact you (in NetMeeting, CU-SeeMe or other services).

You can also access your FTP server or Web site on your own computer using a DNS-like address (for

example, myhost.dhs.org, where myhost is a name of your choice) that will never change instead of using an

IP address that changes each time you reconnect. Your friends or relatives will always be able to call you

even if they don’t know your IP address.

General and WAN Setup 4-1

ZyWALL 50 Internet Security Gateway

First of all, you need to have registered a dynamic DNS account with www.dyndns.org. This is for people

with a dynamic IP from their ISP or DHCP server that would still like to have a DNS name.

To use this service, you must register with the Dynamic DNS service provider. The Dynamic DNS service

provider will give you a password or key. The ZyWALL supports www.dyndns.org. You can apply to this

service provider for Dynamic DNS service.

Menu 1.1 - Configure Dynamic DNS

Service Provider= WWW.DynDNS.ORG
Active= Yes
DDNSType= DynamicDNS
Host=
EMAIL=
USER=
Password= ********
Enable Wildcard= No
Offline= N/A

Press ENTER to confirm or ESC to cancel:

Figure 4-1 Configure Dynamic DNS

Follow the instructions in the next table to configure Dynamic DNS parameters.

Table 4-1 Configure Dynamic DNS Menu Fields

FIELD DESCRIPTION EXAMPLE

Service Provider This is the name of your Dynamic DNS service provider. WWW.DynDNS.ORG

(default)

Active

Press [SPACE BAR] to select Yes and then press [ENTER] to

Yes

make dynamic DNS active.

DDNS Type

Press [SPACE BAR] and then [ENTER] to select DynamicDNS
if you have a dynamic IP address(es). Select StaticDNS if you

DynamicDNS

(defautl)

have a static IP address(s).

Select CustomDNS to have dyns.org provide DNS service for a
domain name that you already have from a source other than
dyndns.org.

At the time of writing, dyndns.org provides the basic
DynamicDNS and StaticDNS services along with a limited
number of hostnames for free, but charges a fee for
CustomDNS. See www.dyndns.org

for details.

4-2 General and WAN Setup

ZyWALL 50 Internet Security Gateway

FIELD DESCRIPTION EXAMPLE

Host Enter the domain name assigned to your ZyWALL by your

Dynamic DNS provider.

EMAIL Enter your e-mail address. mail@mailserver

USER Enter your user name.

Password Enter the password assigned to you.

Enable Wildcard Your ZyWALL supports DYNDNS Wildcard. Press [SPACE BAR]

and then [ENTER] to select Yes or No This field is N/A when
you choose DDNS client as your service provider.

Offline

When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to save
your configuration, or press [ESC] at any time to cancel.

This field is only available when CustomDNS is selected in the
DDNS Type field. Press [SPACE BAR] and then [ENTER] to
select Yes. When Yes is selected, traffic is redirected to a URL
that you have previously specified (see www.dyndns.org
details).

for

me.dyndns.org

No

Yes

The IP address will be updated when you reconfigure menu 1 or perform DHCP client renewal.

If you have a private WAN IP address, then you cannot use Dynamic DNS.

4.3 WAN Setup

This section describes how to configure the WAN using Menu 2 — WAN Setup. From the main menu,

enter 2 to open menu 2.

ZyXEL recommends you configure this menu even if your ISP does not require

MAC address authentication.

General and WAN Setup 4-3

ZyWALL 50 Internet Security Gateway

MAC Address:

Assigned By= Factory default

Press Space Bar to Toggle

IP Address= N/A

Press ENTER to Confirm or ESC to Cancel:

Menu 2 - WAN Setup

Figure 4-2 Menu 2 — WAN Setup

The MAC address field allows users to configure the WAN port's MAC address by using either the factory

default or cloning the MAC address from a computer on your LAN. Once it is successfully configured, the

address will be copied to the rom file (ZyNOS configuration file). It will not change unless you change the

setting in menu 2 or upload a different rom file.

The following table contains instructions on how to configure your WAN setup.

Table 4-2 WAN Setup Menu Fields

FIELD DESCRIPTION EXAMPLE

MAC Address

Assigned By Press [SPACE BAR] to choose one of two methods to assign a MAC

Address. Choose Factory Default to select the factory assigned
default MAC Address. Choose IP Address attached on LAN to use
the MAC Address of that computer whose IP you give in the following
field.

IP Address

This field is applicable only if you choose the IP Address attached
on LAN method. Enter the IP address of the computer on the LAN
whose MAC you are cloning.

When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to save
your configuration, or press [ESC] at any time to cancel.

Factory

default

N/A

4-4 General and WAN Setup

ZyWALL 50 Internet Security Gateway

Chapter 5

LAN Setup

This chapter describes how to configure the LAN using Menu 3 – LAN Setup.

5.1 Introduction

This section describes how to configure the LAN using Menu 3 — LAN Setup. From the main menu, enter
3 to open menu 3.

Menu 3 - LAN Setup

1. LAN Port Filter Setup

2. TCP/IP and DHCP Setup

Enter Menu Selection Number:

Figure 5-1 Menu 3 — LAN Setup

5.2 LAN Port Filter Setup

This menu allows you to specify the filter sets that you wish to apply to the LAN traffic. You seldom need to
filter the LAN traffic, however, the filter sets may be useful to block certain packets, reduce traffic and
prevent security breaches. Menu 3.2 is discussed in the next chapter. Please read on.

Menu 3.1 – LAN Port Filter Setup

Input Filter Sets:

protocol filters= 2
device filters=

Output Filter Sets:

protocol filters=
device filters=

Press ENTER to Confirm or ESC to Cancel:

Figure 5-2 Menu 3.1 — LAN Port Filter Setup

5.3 TCP/IP and DHCP for LAN

The ZyWALL has built-in DHCP server capability that assigns IP addresses and DNS servers to systems that
support DHCP client capability.

LAN Setup 5-1

ZyWALL 50 Internet Security Gateway

5.3.1 Factory LAN Defaults

The LAN parameters of the ZyWALL are preset in the factory with the following values:

1. IP address of 192.168.1.1 with subnet mask of 255.255.255.0 (24 bits).

2. DHCP server enabled with 32 client IP addresses starting from 192.168.1.33.

These parameters should work for the majority of installations. If your ISP gives you an explicit DNS server
address(es), skip ahead to section 5.4 to see how to enter the DNS server address(es).

5.3.2 DHCP Configuration

DHCP (Dynamic Host Configuration Protocol, RFC 2131 and RFC 2132) allows individual clients to obtain
TCP/IP configuration at start-up from a server. You can configure the ZyWALL as a DHCP server or disable
it. When configured as a server, the ZyWALL provides the TCP/IP configuration for the clients. If set to
None, DHCP service will be disabled and you must have another DHCP server on your LAN, or else the
workstation must be manually configured.

IP Pool Setup

The ZyWALL is pre-configured with a pool of 32 IP addresses starting from 192.168.1.33 to 192.168.1.64.
This configuration leaves 31 IP addresses (excluding the ZyWALL itself) in the lower range for other server
machines, e.g., server for mail, FTP, Telnet, web, etc., that you may have.

DNS Server Address

Use DNS (Domain Name System) to map a domain name to its corresponding IP address and vice versa, e.g.,
the IP address of www.zyxel.com is 204.217.0.2. The DNS server is extremely important because without it,
you must know the IP address of a machine before you can access it.
There are two ways that an ISP disseminates the DNS server addresses.
The first is for an ISP to tell a customer the DNS server addresses, usually in the form of an information
sheet, when you sign up. If your ISP gives you the DNS server addresses, enter them in the DNS Server
fields in DHCP Setup.
The second is to leave this field blank, i.e., 0.0.0.0 — in this case, the ZyWALL acts as a DNS proxy.

Table 5-1 Example of Network Properties for LAN Servers with Fixed IP Addresses

Choose an IP address

Subnet mask 255.255.255.0

Gateway (or default route) 192.168.1.1 (ZyWALL LAN IP address)

192.168.1.2 - 192.168.1.32; 192.168.1.65 - 192.168.1.254

5.3.3 IP Address and Subnet Mask

Similar to the way houses on a street share a common street name, so too do computers on a LAN share one
common network number.

5-2 LAN Setup

ZyWALL 50 Internet Security Gateway

Where you obtain your network number depends on your particular situation. If the ISP or your network
administrator assigns you a block of registered IP addresses, follow their instructions in selecting the IP
addresses and the subnet mask.
If the ISP did not explicitly give you an IP network number, then most likely you have a single user account
and the ISP will assign you a dynamic IP address when the connection is established. If this is the case, it is
recommended that you select a network number from 192.168.0.0 to 192.168.255.0 and you must enable the
Network Address Translation (NAT) feature of the ZyWALL. The Internet Assigned Number Authority
(IANA) reserved this block of addresses specifically for private use; please do not use any other number
unless you are told otherwise. Let’s say you select 192.168.1.0 as the network number; which covers 254
individual addresses, from 192.168.1.1 to 192.168.1.254 (zero and 255 are reserved). In other words, the first
three numbers specify the network number while the last number identifies an individual workstation on that
network.
Once you have decided on the network number, pick an IP address that is easy to remember, e.g.,

192.168.1.1, for your ZyWALL, but make sure that no other device on your network is using that IP.
The subnet mask specifies the network number portion of an IP address. Your ZyWALL will compute the
subnet mask automatically based on the IP address that you entered. You don’t need to change the subnet
mask computed by the ZyWALL unless you are instructed to do otherwise.

5.3.4 Private IP Addresses

Every computer on the Internet must have a unique IP address. If your networks are isolated from the
Internet, e.g., only between your two branch offices, you can assign any IP addresses to the hosts without
problems. However, the Internet Assigned Numbers Authority (IANA) has reserved the following three
blocks of IP addresses specifically for private networks:

Table 5-2 Private IP Address Ranges

10.0.0.0 — 10.255.255.255

172.16.0.0 — 172.31.255.255

192.168.0.0 — 192.168.255.255

You can obtain your IP address from the IANA, from an ISP or have it assigned by a private network. If you
belong to a small organization and your Internet access is through an ISP, the ISP can provide you with the
Internet addresses for your local networks. On the other hand, if you are part of a much larger organization,
you should consult your network administrator for the appropriate IP addresses.

LAN Setup 5-3

ZyWALL 50 Internet Security Gateway

Regardless of your particular situation, do not create an arbitrary IP address;

always follow the guidelines above. For more information on address assignment,

please refer to RFC 1597, Address Allocation for Private Internets and RFC 1466,

Guidelines for Management of IP Address Space.

5.3.5 RIP Setup

RIP (Routing Information Protocol, RFC1058 and RFC 1389) allows a router to exchange routing
information with other routers. The RIP Direction field controls the sending and receiving of RIP packets.
When set to Both or Out Only, the ZyWALL will broadcast its routing table periodically. When set to
Both or In Only, it will incorporate the RIP information that it receives; when set to None, it will not send
any RIP packets and will ignore any RIP packets received.
The Version field controls the format and the broadcasting method of the RIP packets that the ZyWALL
sends (it recognizes both formats when receiving). RIP-1 is universally supported; but RIP-2 carries more
information. RIP-1 is probably adequate for most networks, unless you have an unusual network topology.
Both RIP-2B and RIP-2M sends the routing data in RIP-2 format; the difference being that RIP-2B uses
subnet broadcasting while RIP-2M uses multicasting. Multicasting can reduce the load on non-router
machines since they generally do not listen to the RIP multicast address and so will not receive the RIP
packets. However, if one router uses multicasting, then all routers on your network must use multicasting,
also.
By default, RIP Direction is set to Both and the Version set to RIP-1.

5.3.6 IP Multicast

Traditionally, IP packets are transmitted in one of either two ways - Unicast (1 sender — 1 recipient) or
Broadcast (1 sender — everybody on the network). Multicast delivers IP packets to a group of hosts on the
network - not everybody and not just 1.
IGMP (Internet Group Multicast Protocol) is a session-layer protocol used to establish membership in a
Multicast group - it is not used to carry user data. IGMP version 2 (RFC 2236) is an improvement over
version 1 (RFC 1112) but IGMP version 1 is still in wide use. If you would like to read more detailed
information about interoperability between IGMP version 2 and version 1, please see sections 4 and 5 of
RFC 2236. The class D IP address is used to identify host groups and can be in the range 224.0.0.0 to

239.255.255.255. The address 224.0.0.0 is not assigned to any group and is used by IP multicast computers.
The address 224.0.0.1 is used for query messages and is assigned to the permanent group of all IP hosts
(including gateways). All hosts must join the 224.0.0.1 group in order to participate in IGMP. The address

224.0.0.2 is assigned to the multicast routers group.
The ZyWALL supports both IGMP version 1 (IGMP-v1) and IGMP version 2 (IGMP-v2). At start up, the
ZyWALL queries all directly connected networks to gather group membership. After that, the ZyWALL
periodically updates this information. IP Multicasting can be enabled/disabled on the ZyWALL LAN and/or
WAN interfaces using menus 3.2 (LAN) and 11.3 (WAN). Select None to disable IP Multicasting on these
interfaces.

5-4 LAN Setup

ZyWALL 50 Internet Security Gateway

5.3.7 IP Alias

IP Alias allows you to partition a physical network into different logical networks over the same Ethernet
interface. The ZyWALL supports three logical LAN interfaces via its single physical Ethernet interface with
the ZyWALL itself as the gateway for each LAN network.

Figure 5-3 Physical Network Figure 5-4 Partitioned Logical Networks

Use menu 3.2.1 to configure IP Alias on your ZyWALL.

5.4 TCP/IP and DHCP Ethernet Setup Menu

From the main menu, enter 3 to open Menu 3 - LAN Setup to configure TCP/IP (RFC 1155) and DHCP
Ethernet setup.

Menu 3 – LAN Setup

1. LAN Port Filter Setup

2. TCP/IP and DHCP Setup

Enter Menu Selection Number:

Figure 5-5 Menu 3 — TCP/IP and DHCP Setup

From menu 3, select the submenu option TCP/IP and DHCP and press [ENTER]. The screen now displays
Menu 3.2 — TCP/IP and DHCP Ethernet Setup, as shown next.

LAN Setup 5-5

ZyWALL 50 Internet Security Gateway

Menu 3.2 - TCP/IP and DHCP Ethernet Setup

DHCP= Server
Configuration:

Client IP Pool Starting Address= 192.168.1.33
Size of Client IP Pool= 32
Primary DNS Server= 0.0.0.0
Secondary DNS Server= 0.0.0.0

DHCP Server Address= N/A

TCP/IP Setup:

IP Address= 192.168.1.1
IP Subnet Mask= 255.255.255.0
RIP Direction= Both

Version= RIP-1
Multicast= None
Edit IP Alias= No

Press ENTER to Confirm or ESC to Cancel:

First address
in the IP Pool

Size of the IP
Pool

IP addresses
of the DNS
servers

Figure 5-6 Menu 3.2 — TCP/IP and DHCP Ethernet Setup

Follow the instructions in the next table on how to configure the DHCP fields.

Table 5-3 DHCP Ethernet Setup Menu Fields

FIELD DESCRIPTION EXAMPLE

DHCP This field enables/disables the DHCP server.

If set to Server, your ZyWALL will act as a DHCP server.
If set to None, the DHCP server will be disabled.
If set to Relay, the ZyWALL acts as a surrogate DHCP server and relays
requests and responses between the remote server and the clients.

When set to Server, the following four items need to be set:

Server

Configuration:

Client IP Pool

Starting Address

Size of Client IP

This field specifies the first of the contiguous addresses in the IP address

192.168.1.33

pool.

This field specifies the size, or count of the IP address pool. 32

Pool

Primary DNS

Type in the IP addresses of the DNS servers. The DNS servers are passed

Server

to the DHCP clients along with the IP address and the subnet mask.

Secondary DNS

Server

5-6 LAN Setup

ZyWALL 50 Internet Security Gateway

Table 5-3 DHCP Ethernet Setup Menu Fields

FIELD DESCRIPTION EXAMPLE

DHCP Server

Address

If Relay is selected in the DHCP field above, then type in the IP address of
the actual, remote DHCP server here.

Follow the instructions in the following table to configure TCP/IP parameters for the LAN port.

Table 5-4 LAN TCP/IP Setup Menu Fields

FIELD DESCRIPTION EXAMPLE

TCP/IP Setup:

IP Address Enter the IP address of your ZyWALL in dotted decimal notation 192.168.1.1

(default)

IP Subnet Mask Your ZyWALL will automatically calculate the subnet mask based on

the IP address that you assign. Unless you are implementing
subnetting, use the subnet mask computed by the ZyWALL.

RIP Direction

Version Press [SPACE BAR] to select the RIP version. Options are:

Multicast IGMP (Internet Group Multicast Protocol) is a session-layer protocol

Edit IP Alias The ZyWALL supports three logical LAN interfaces via its single

When you have completed this menu, press [ENTER] at the prompt [Press ENTER to Confirm…] to save
your configuration, or press [ESC] at any time to cancel.

Press [SPACE BAR] to select the RIP direction. Options are: Both,

In Only, Out Only or None.

RIP-1, RIP-2B or RIP-2M.

used to establish membership in a Multicast group. The ZyWALL
supports both IGMP version 1 (IGMP-v1) and version 2 (IGMP-v2).
Press [SPACE BAR] to enable IP Multicasting or select None
(default) to disable it.

physical Ethernet interface with the ZyWALL itself as the gateway
for each LAN network. Press [SPACE BAR] to select Yes, then
press [ENTER] to display menu 3.2.1

255.255.255.0

Both

(default)

RIP-1

(default)

None

Yes

5.4.1 IP Alias Setup

Use menu 3.2 to configure the first network. Move the cursor to the Edit IP Alias field, press [SPACE
BAR] to choose Yes and press [ENTER] to configure the second and third network.
Pressing [ENTER] opens Menu 3.2.1 - IP Alias Setup, as shown next.

LAN Setup 5-7

ZyWALL 50 Internet Security Gateway

Menu 3.2.1 - IP Alias Setup

IP Alias 1= No

IP Address= N/A
IP Subnet Mask= N/A
RIP Direction= N/A

Version= N/A
Incoming protocol filters= N/A
Outgoing protocol filters= N/A

IP Alias 2= No

IP Address= N/A
IP Subnet Mask= N/A
RIP Direction= N/A

Version= N/A
Incoming protocol filters= N/A
Outgoing protocol filters= N/A

Enter here to CONFIRM or ESC to CANCEL:

Press Space Bar to Toggle.

Figure 5-7 Menu 3.2.1 — IP Alias Setup

Use the instructions in the following table to configure IP Alias parameters.

Table 5-5 IP Alias Setup Menu Fields

FIELD DESCRIPTION EXAMPLE

IP Alias

IP Address Enter the IP address of your ZyWALL in dotted decimal notation. 192.168.2.1

IP Subnet Mask Your ZyWALL will automatically calculate the subnet mask based on

RIP Direction Press [SPACE BAR] to select the RIP direction. Options are:

Version Press [SPACE BAR] to select the RIP version. Options are:

Choose Yes to configure the LAN network for the ZyWALL. Yes

255.255.255.0
the IP address that you assign. Unless you are implementing
subnetting, use the subnet mask computed by the ZyWALL.

None

Both, In Only, Out Only or None.

RIP-1

RIP-1, RIP-2B or RIP-2M.

Incoming
Protocol Filters

Outgoing
Protocol Filters

Enter the filter set(s) you wish to apply to the incoming traffic
between this node and the ZyWALL.

Enter the filter set(s) you wish to apply to the outgoing traffic between
this node and the ZyWALL.

1

2

When you have completed this menu, press [ENTER] at the prompt [Press ENTER to Confirm…] to save
your configuration, or press [ESC] at any time to cancel.

5-8 LAN Setup

ZyWALL 50 Internet Security Gateway

Chapter 6

Internet Access

This chapter shows you how to configure your ZyWALL for Internet access.

6.1 Internet Access Setup

You will see three different menu 4 screens depending on whether you chose Ethernet, PPTP or PPPoE

Encapsulation.

6.1.1 Ethernet Encapsulation

You must choose the Ethernet option when the WAN port is used as a regular Ethernet. The PPPoE choice
is for a dial-up connection using PPPoE. If you choose Ethernet in menu 4 you will see the next screen.

Menu 4 - Internet Access Setup

ISP's Name= ChangeMe
Encapsulation= Ethernet

Service Type= Standard
My Login= N/A
My Password= N/A
Login Server IP= N/A

IP Address Assignment= Dynamic

IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Address= N/A

Network Address Translation= SUA Only

Press ENTER to Confirm or ESC to Cancel:

Figure 6-1 Menu 4 — Internet Access Setup (Ethernet)

The following table describes this screen.

Table 6-1 Internet Access Setup Menu Fields

FIELD DESCRIPTION

ISP’s Name Enter the name of your Internet Service Provider, e.g., myISP. This

information is for identification purposes only.

Internet Access 6-1

ZyWALL 50 Internet Security Gateway

Table 6-1 Internet Access Setup Menu Fields

FIELD DESCRIPTION

Encapsulation

Service Type

Note: xDSL users must choose the Standard option only. The Server IP, My Login IP and My
Password fields are not applicable in this case.

My Login Name Enter the login name given to you by your ISP.

My Password Enter the password associated with the login name above.

Login Server IP The ZyWALL will find the RoadRunner Server IP if this field is left blank. If it

IP Address Assignment

IP Address Enter the (fixed) IP address assigned to you by your ISP (Static IP Address

IP Subnet Mask Enter the subnet mask associated with your static IP.

Gateway IP Address Enter the gateway IP address associated with your static IP.

Network Address
Translation

Press [SPACE BAR] and then press [ENTER] to choose Ethernet. The
encapsulation method influences your choices for IP Address.

Press [SPACE BAR] to select Standard, RR-Toshiba (RoadRunner Toshiba
authentication method) or RR-Manager (RoadRunner Manager
authentication method). Choose a RoadRunner flavor if your ISP is Time
Warner's RoadRunner; otherwise choose Standard.

does not, then you must enter the authentication server IP address.

If your ISP did not assign you a fixed IP address, select Dynamic, otherwise
select Static and enter the IP address & subnet mask in the following fields.

Assignment is selected in the previous field).

Please see the NAT chapter for a more detailed discussion on the Network
Address Translation feature. The choices are Full Feature, None and SUA
Only.

When you have completed this menu, press [ENTER] at the prompt “Press ENTER to Confirm…” to save
your configuration, or press [ESC] at any time to cancel.

6.1.2 PPTP Encapsulation

Point-to-Point Tunneling Protocol (PPTP) is a network protocol that enables secure transfer of data from a
remote client to a private server, creating a Virtual Private Network (VPN) using TCP/IP-based networks
PPTP supports on-demand, multi-protocol, and virtual private networking over public networks, such as the
Internet.

6-2 Internet Access

ZyWALL 50 Internet Security Gateway

The ZyWALL 50 supports one PPTP server connection at any given time.

6.1.3 Configuring the PPTP Client

To configure a PPTP client, you must configure the My Login and Password fields for a PPP connection and
the PPTP parameters for a PPTP connection.

After configuring My Login and Password for PPP connection, press [SPACE BAR] in the Encapsulation
field in Menu 4 -Internet Access Setup to choose PPTP as your encapsulation option. This brings up the
following screen.

Menu 4 - Internet Access Setup

ISP's Name= ChangeMe
Encapsulation= PPTP

Service Type= N/A
My Login=
My Password= ******
Idle Timeout= 100

IP Address Assignment= Dynamic

IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Address=N/A

Network Address Translation= SUA Only

Press ENTER to Confirm or ESC to Cancel:

Figure 6-2 Internet Access Setup (PPTP)

The following table contains instructions about the new fields when you choose PPTP in the Encapsulation
field in menu 4.

Table 6-2 New Fields in Menu 4 (PPTP) screen

FIELD DESCRIPTION EXAMPLE

Encapsulation Press [SPACE BAR] and then press [ENTER] to choose

PPTP

PPTP. The encapsulation method influences your choices for

IP Address.

Idle Timeout This value specifies the time in seconds that elapses before

the ZyWALL automatically disconnects from the PPTP

100

(default)

server.

Internet Access 6-3

ZyWALL 50 Internet Security Gateway

6.1.4 PPPoE Encapsulation

The ZyWALL supports PPPoE (Point-to-Point Protocol over Ethernet). PPPoE is an IETF Draft standard
(RFC 2516) specifying how a personal computer (PC) interacts with a broadband modem (i.e. xDSL, cable,
wireless, etc.) connection.

For the service provider, PPPoE offers an access and authentication method that works with existing access
control systems (e.g., Radius). For the user, PPPoE provides a login & authentication method that the
existing Microsoft Dial-Up Networking software can activate, and therefore requires no new learning or
procedures for Windows users.

One of the benefits of PPPoE is the ability to let end users access one of multiple network services, a function
known as dynamic service selection. This enables the service provider to easily create and offer new IP
services for specific users.
Operationally, PPPoE saves significant effort for both the end user and ISP/carrier, as it requires no specific
configuration of the broadband modem at the customer site.

By implementing PPPoE directly on the ZyWALL 50 (rather than individual computer’s), the computers on
the LAN do not need PPPoE software installed, since the ZyWALL does that part of the task. Furthermore,
with NAT, all of the LAN’s computers will have access.

If you enable PPPoE in menu 4, you will see the next screen. For more information on PPPoE, please see the
Appendices.

Menu 4 - Internet Access Setup

ISP's Name= ChangeMe
Encapsulation= PPPoE

Service Type=
My Login=
My Password= ********
Idle Timeout= 100

IP Address Assignment= Dynamic

IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Address= N/A

Network Address Translation= SUA Only

Press ENTER to Confirm or ESC to Cancel:

Figure 6-3 Internet Access Setup (PPPoE)

Table 6-3 New Fields in Menu 4 (PPPoE) screen

FIELD DESCRIPTION EXAMPLE

Encapsulation

Press [SPACE BAR] and then press [ENTER] to choose PPPoE. The

PPPoE

6-4 Internet Access

ZyWALL 50 Internet Security Gateway

Table 6-3 New Fields in Menu 4 (PPPoE) screen

FIELD DESCRIPTION EXAMPLE

Encapsulation

Idle Timeout This value specifies the time in seconds that elapses before the

Press [SPACE BAR] and then press [ENTER] to choose PPPoE. The
encapsulation method influences your choices for IP Address.

ZyWALL automatically disconnects from the PPPoE server.

PPPoE

100

(default)

If you need a PPPoE service name to identify and reach the PPPoE server, please go to menu 11 and enter the
PPPoE service name provided to you in the Service Name field.

6.2 Basic Setup Complete

Well done! You have successfully connected, installed and set up your ZyWALL to operate on your network
as well as access the Internet.

When the firewall is activated the default policy allows all communications to the

Internet that originate from the LAN and blocks all traffic to the LAN that originates

from the Internet.

You may deactivate the firewall in menu 21.2 or via the ZyWALL web configurator. You may also define
additional firewall rules or modify existing ones but please exercise extreme caution in doing so. See the
firewall part.

Internet Access 6-5

Advanced Applications

Part II:

Advanced Applications

This part covers Remote Node Setup, IP Static Route Setup and Network Address Translation.

II

ZyWALL 50 Internet Security Gateway

Chapter 4

Remote Node Setup

This chapter shows you how to configure a remote node.

A remote node is required for placing calls to a remote gateway. A remote node represents both the remote

gateway and the network behind it across a WAN connection. Note that when you use menu 4 to set up

Internet access, you are actually configuring a remote node. We will show you how to configure Menu 11.1

Remote Node Profile, Menu 11.3 - Remote Node Network Layer Options and Menu 11.5 - Remote

Node Filter.

4.1 Remote Node Profile

From the main menu, select menu option 11 to open Menu 11.1 - Remote Node Profile. There are two

variations of this menu depending on whether you choose Ethernet Encapsulation or PPPoE

Encapsulation.

4.1.1 Ethernet Encapsulation

You must choose the Ethernet option when the WAN port is used as a regular Ethernet. The first menu

11.1 screen you see is for Ethernet encapsulation shown next.

Remote Node Setup 4-1

ZyWALL 50 Internet Security Gateway

Rem Node Name= ChangeMe Route= IP
Active= Yes

Encapsulation= Ethernet Edit IP= No
Service Type= Standard Session Options:
Service Name= N/A Edit Filter Sets= No
Outgoing:

My Login= N/A
My Password= N/A
Server IP= N/A

Press ENTER to Confirm or ESC to Cancel:

Figure 4-1 Menu 11.1 — Remote Node Profile for Ethernet Encapsulation

Table 4-1 Fields in Menu 11.1

FIELD DESCRIPTION EXAMPLE

Menu 11.1 - Remote Node Profile

Rem Node Name Enter a descriptive name for the remote node. This field can be

LAoffice

up to eight characters.

Active

Press [SPACE BAR] to select Yes (activate remote node) or No

Yes

(deactivate remote node).

Encapsulation

Ethernet is the default encapsulation. Press [SPACE BAR] if you

Ethernet

wish to change to PPPoE encapsulation.

Service Type

Press [SPACE BAR] to select from Standard, RR-Toshiba

Standard

(RoadRunner Toshiba authentication method) or RR-Manager
(RoadRunner Manager authentication method). Choose one of
the RoadRunner methods if your ISP is Time Warner's
RoadRunner; otherwise choose Standard.

Service Name

This is valid only when you have chosen PPPoE encapsulation. If

poellc
you are using PPPoE encapsulation, then type the name of your
PPPoE service here.

Outgoing

My Login

This field is applicable for PPPoE encapsulation only. Enter the

jim
login name assigned by your ISP when the ZyWALL calls this
remote node. Some ISPs append this field to the Service Name
field above (e.g., jim@poellc) to access the PPPoE server.

4-2 Remote Node Setup

ZyWALL 50 Internet Security Gateway

Table 4-1 Fields in Menu 11.1

FIELD DESCRIPTION EXAMPLE

My Password Enter the password assigned by your ISP when the ZyWALL calls

this remote node. Valid for PPPoE encapsulation only.

Server IP This field is valid for RoadRunner service type only. The ZyWALL

will find the RoadRunner Server IP automatically if this field is left
blank. If it does not, then you must enter the authentication server
IP address here.

Route This field refers to the protocol that will be routed by your

ZyWALL – IP is the only option for the ZyWALL 50.

Edit IP This field leads to a “hidden” menu. Press [SPACE BAR] to select

Yes and press [ENTER] to go to Menu 11.3 - Remote Node
Network Layer Options.

Session Options

Edit Filter sets

Once you have configured the Remote Node Profile Menu, press [ENTER] to return to menu 11. Press
[ENTER] at the message “Press ENTER to Confirm...” to save your configuration, or press [ESC] at any
time to cancel.

This field leads to another “hidden” menu. Use [SPACE BAR] to
select Yes and press [ENTER] to open menu 11.5 to edit the filter
sets. See the Remote Node Filter section for more details.

*****

IP

Yes

Yes

4.1.2 PPPoE Encapsulation

The ZyWALL supports PPPoE (Point-to-Point Protocol over Ethernet). You can only use PPPoE

encapsulation when you’re using the ZyWALL with an xDSL modem as the WAN device. If you change

the Encapsulation to PPPoE, then you will see the next screen. Please see the Appendices for more

information on PPPoE.

Remote Node Setup 4-3

ZyWALL 50 Internet Security Gateway

Menu 11.1 - Remote Node Profile

Rem Node Name= ChangeMe Route= IP
Active= Yes

Encapsulation= PPPoE Edit IP= No
Service Type= Standard Telco Option:
Service Name= Allocated Budget(min)= 0
Outgoing= Period(hr)= 0

My Login= Schedules=
My Password= ******** Nailed-Up Connection= No
Authen= CHAP/PAP

Press ENTER to Confirm or ESC to Cancel:

Press Space Bar to Toggle.

Session Options:

Edit Filter Sets= No
Idle Timeout(sec)= 100

Figure 4-2 Menu 11.1 — Remote Node Profile for PPPoE Encapsulation

Outgoing Authentication Protocol

Generally speaking, you should employ the strongest authentication protocol possible, for obvious reasons.

However, some vendor’s implementation includes specific authentication protocol in the user profile. It

will disconnect if the negotiated protocol is different from that in the user profile, even when the negotiated

protocol is stronger than specified. If you encounter the case where the peer disconnects right after a

successful authentication, please make sure that you specify the correct authentication protocol when

connecting to such an implementation.

Nailed-Up Connection

A nailed-up connection is a dial-up line where the connection is always up regardless of traffic demand.

The ZyWALL does two things when you specify a nailed-up connection. The first is that idle timeout is

disabled. The second is that the ZyWALL will try to bring up the connection when turned on and whenever

the connection is down. A nailed-up connection can be very expensive for obvious reasons.

Do not specify a nailed-up connection unless your telephone company offers flat-rate service or you need a

constant connection and the cost is of no concern.

The following table describes the fields not already described in Table 4-1.

4-4 Remote Node Setup

ZyWALL 50 Internet Security Gateway

Table 4-2 Fields in Menu 11.1 (PPPoE Encapsulation Specific)

FIELD DESCRIPTION EXAMPLE

Authen This field sets the authentication protocol used for outgoing

calls.

Options for this field are:

CHAP/PAP - Your ZyWALL will accept either CHAP or PAP
when requested by this remote node.

CHAP - accept CHAP only.

PAP - accept PAP only.

Telco Option

Allocated Budget The field sets a ceiling for outgoing call time for this remote

node. The default for this field is 0 meaning no budget control.

Period(hr) This field is the time period that the budget should be reset. For

example, if we are allowed to call this remote node for a
maximum of 10 minutes every hour, then the Allocated
Budget is (10 minutes) and the Period(hr) is 1 (hour).

Schedules You can apply up to four schedule sets here. For more details

please refer to the Call Schedule Setup chapter.

Nailed-Up

Connection

Session Options

Idle Timeout

This field specifies if you want to make the connection to this
remote node a nailed-up connection. More details are given
earlier in this section.

This value specifies the idle time (i.e., the length of time there
is no traffic from the ZyWALL to the remote node) in seconds
that can elapse before the ZyWALL automatically disconnects
the PPPoE connection. This option only applies when the

ZyWALL initiates the call.

CHAP/PAP

10

1

100 seconds

(default)

4.1.3 PPTP Encapsulation

If you change the Encapsulation to PPTP in menu 11.1, then you will see the next screen. Please see the

Appendices for information on PPTP.

Remote Node Setup 4-5

ZyWALL 50 Internet Security Gateway

Menu 11.1 - Remote Node Profile

Rem Node Name= ChangeMe Route= IP
Active= Yes

Encapsulation= PPTP Edit IP= No
Service Type= Standard Telco Option:
Service Name=N/A Allocated Budget(min)= 0
Outgoing= Period(hr)= 0

My Login= Schedules=
My Password= ******** Nailed-up Connections= No
Authen= CHAP/PAP

PPTP : Edit Filter Sets= No

My IP Addr= Idle Timeout(sec)= 100
Server IP Addr=
Connection ID/Name=

Press ENTER to Confirm or ESC to Cancel:

Press Space Bar to Toggle.

Session Options:

Figure 4-3 Menu 11.1 — Remote Node Profile for PPTP Encapsulation

The next table shows how to configure fields in menu 11.1 not previously discussed above.

Table 4-3 Fields in Menu 11.1 (PPTP Encapsulation)

FIELD DESCRIPTION EXAMPLE

Encapsulation

Toggle the space bar to choose PPTP. You must also go to menu

11.3 to check the IP Address setting once you have selected the
encapsulation method.

My IP Addr Enter the IP address of the WAN Ethernet port. 10.0.0.140

My Server IP

Enter the IP address of the ANT modem. 10.0.0.138

Addr

Connection

ID/Name

Enter the connection ID or connection name in the ANT. It must
follow the “c:id” and “n:name” format.

This field is optional and depends on the requirements of your xDSL
Modem.

Schedules You can apply up to four schedule sets here. For more details

please refer to the Call Schedule Setup chapter.

Nailed-Up
Connections

Press [SPACE BAR] and then [ENTER] to select Yes if you want to
make the connection to this remote node a nailed-up connection.

PPTP

n:My ISP

No

4-6 Remote Node Setup

ZyWALL 50 Internet Security Gateway

p

4.2 Editing TCP/IP Options (with Ethernet Encapsulation)

Move the cursor to the Edit IP field in menu 11.1, press [SPACE BAR] to select Yes. Press [ENTER] to

open Menu 11.3 - Network Layer Options.

Menu 11.3 - Remote Node Network Layer Options

IP Address Assignment= Dynamic
IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Addr= N/A

Network Address Translation= SUA Only

Press Space Bar to Toggle

Figure 4-4 Menu 11.3 — Remote Node Network Layer Options

The next table gives you instructions about configuring remote node network layer options.

Metric= N/A
Private= N/A
RIP Direction= None

Version= N/A

Multicast= None

Enter here to CONFIRM or ESC to CANCEL:

Table 4-4 Remote Node Network Layer Options Menu Fields

FIELD DESCRIPTION EXAMPLE

IP Address
Assignment

If your ISP did not assign you an explicit IP address, select Dynamic;
otherwise select Static and enter the IP address & subnet mask in the

Dynamic

following fields.

IP Address If you have a Static IP Assignment, enter the IP address assigned to you

by your ISP.

IP Subnet
Mask

Gateway IP
Addr

Network
Address

If you have a Static IP Assignment, enter the subnet mask assigned to
you.

If you have a Static IP Assignment, enter the gateway IP address
assigned to you.

Use [SPACE BAR] to select either Full Feature, None or SUA Only. See
the NAT chapter for a full discussion on this feature.

SUA Only

Translation

Metric This field is valid only for PPTP/PPPoE encapsulation. The metric

resents the “cost” of transmission for routing purposes. IP routing

re

3

Remote Node Setup 4-7

ZyWALL 50 Internet Security Gateway

Table 4-4 Remote Node Network Layer Options Menu Fields

FIELD DESCRIPTION EXAMPLE

Metric This field is valid only for PPTP/PPPoE encapsulation. The metric

represents the “cost” of transmission for routing purposes. IP routing
uses hop count as the measurement of cost, with a minimum of 1 for
directly connected networks. Enter a number that approximates the cost
for this link. The number need not be precise, but it must be between 1
and 15. In practice, 2 or 3 is usually a good number.

Private This field is valid only for PPTP/PPPoE encapsulation. This parameter

determines if the ZyWALL will include the route to this remote node in its
RIP broadcasts. If set to Yes, this route is kept private and not included in
RIP broadcast. If No, the route to this remote node will be propagated to
other hosts through RIP broadcasts.

RIP

Version

Multicast IGMP (Internet Group Multicast Protocol) is a session-layer protocol used

Once you have completed filling in the Network Layer Options Menu, press [ENTER] to return to menu 11.
Press [ENTER] at the message “Press ENTER to Confirm...” to save your configuration, or press [ESC] at
any time to cancel.

Press [SPACE BAR] to select the RIP direction from Both/ None/In
Only/Out Only. Please see the RIP Setup section for more information
on RIP. The default for RIP on the WAN side is None. It is recommended
that you do not change this setting.

Press [SPACE BAR] to select the RIP version from RIP-1/RIP-2B/RIP-
2M or None.

to establish membership in a Multicast group. The ZyWALL supports both
IGMP version 1 (IGMP-v1) and version 2 (IGMP-v2). Press [SPACE
BAR] to enable IP Multicasting or select None to disable it. See the
previous Part for more information on this feature.

3

Yes

None

N/A

None

4.2.1 Editing TCP/IP Options (with PPTP Encapsulation)

Make sure that Encapsulation is set to PPTP in menu 11.1. Then move the cursor to the Edit IP field in

menu 11.1, press the [SPACE BAR] to toggle No to Yes. Press [ENTER]

Layer Options.

4-8 Remote Node Setup

to open Menu 11.3 - Network

ZyWALL 50 Internet Security Gateway

pp

Menu 11.3 - Remote Node Network Layer Options

IP Address Assignment= Dynamic
Rem IP Address= N/A
Rem Subnet Mask= N/A
My WAN Addr= 0.0.0.0

Network Address Translation= Full Feature
Metric= 1
Private= No
RIP Direction= None

Version= N/A

Multicast= None

Press Space Bar to Toggle.

Enter here to CONFIRM or ESC to CANCEL:

Figure 4-5 Menu 11.3 — Remote Node Network Layer Options

The next table gives you instructions about configuring remote node network layer options.

Table 4-5 Remote Node Network Layer Options Menu Fields

FIELD DESCRIPTION EXAMPLE

IP Address
Assignment

If your ISP did not assign you an explicit IP address, select Dynamic;
otherwise select Static and enter the IP address & subnet mask in
the following fields.

Rem IP
Address

Rem IP Subnet
Mask

If you have a Static IP Assignment, enter the IP address assigned
to the remote node.

If you have a Static IP Assignment, enter the subnet mask assigned
to the remote node.

My WAN Addr Some implementations, especially the UNIX derivatives, require the

WAN link to have a separate IP network number from the LAN and
each end must have a unique address within the WAN network
number. If this is the case, enter the IP address assigned to the WAN
port of your ZyWALL.

Note that this is the address assigned to your local ZyWALL, not the
remote router.

Network
Address

Use [SPACE BAR] to select either Full Feature, None or SUA Only.
See the NAT chapter for a full discussion on this feature.

Translation

Metric The metric represents the “cost” of transmission for routing purposes.

IP routing uses hop count as the measurement of cost, with a
minimum of 1 for directly connected networks. Enter a number that

roximates the cost for this link. The number need not be precise,

a

Dynamic

192.168.1.1

255.255.255.0

0.0.0.0

SUA Only

1 to 15

Remote Node Setup 4-9

ZyWALL 50 Internet Security Gateway

Table 4-5 Remote Node Network Layer Options Menu Fields

FIELD DESCRIPTION EXAMPLE

Metric The metric represents the “cost” of transmission for routing purposes.

IP routing uses hop count as the measurement of cost, with a
minimum of 1 for directly connected networks. Enter a number that
approximates the cost for this link. The number need not be precise,
but it must be between 1 and 15. In practice, 2 or 3 is usually a good
number.

Private This parameter determines if the ZyWALL will include the route to

this remote node in its RIP broadcasts. If set to Yes, this route is kept
private and not included in RIP broadcast. If No, the route to this
remote node will be propagated to other hosts through RIP
broadcasts.

RIP

Version

Multicast IGMP (Internet Group Multicast Protocol) is a session-layer protocol

Once you have completed filling in the Network Layer Options Menu, press [ENTER] to return to menu 11.
Press [ENTER] at the message “Press ENTER to Confirm...” to save your configuration, or press [ESC] at
any time to cancel.

Press [SPACE BAR] to select the RIP direction from Both/ None/In
Only/Out Only and None.

Press [SPACE BAR] to select the RIP version from RIP-1/RIP-
2B/RIP-2M.

used to establish membership in a Multicast group. The ZyWALL
supports both IGMP version 1 (IGMP-v1) and version 2 (IGMP-v2).
Press the [SPACE BAR] to enable IP Multicasting or select None to
disable it. See the previous Part for more information on this feature.

1 to 15

Yes

None

(default)

RIP-1

None

4.2.2 Editing TCP/IP Options (with PPPoE Encapsulation)

Make sure Encapsulation is set to PPPoE in menu 11.1. Move the cursor to the Edit IP field in Menu

11.1 and press [SPACE BAR] to select Yes. Press [ENTER]

to open Menu 11.3 - Network Layer

Options. The menu and fields are the same as described for PPTP encapsulation above.

4.3 Remote Node Filter

Move the cursor to the field Edit Filter Sets in menu 11.1, then press [SPACE BAR] to set the value to

Yes. Press [ENTER] to open Menu 11.5 - Remote Node Filter.

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ZyWALL 50 Internet Security Gateway

Use menu 11.5 to specify the filter set(s) to apply to the incoming and outgoing traffic between this remote

node and the ZyWALL to prevent certain packets from triggering calls. You can specify up to 4 filter sets

separated by commas, e.g., 1, 5, 9, 12, in each filter field. Note that spaces are accepted in this field. For

more information on defining the filters, please refer to the Filters chapter. For PPPoE or PPTP

encapsulation, you can also specify remote node call filter sets.

Menu 11.5 - Remote Node Filter

Input Filter Sets:

protocol filters= 3

device filters=

Output Filter Sets:

protocol filters= 1

device filters=

Enter here to CONFIRM or ESC to CANCEL:

Figure 4-6 Menu 11.5 — Remote Node Filter (Ethernet Encapsulation)

Menu 11.5 - Remote Node Filter

Input Filter Sets:

protocol filters= 3

Device filters=

Output Filter Sets:

protocol filters= 1

device filters=

Call Filter Sets:

protocol filters= 1

Device filters=

Enter here to CONFIRM or ESC to CANCEL:

Figure 4-7 Menu 11.5 — Remote Node Filter (PPPoE or PPTP Encapsulation)

Remote Node Setup 4-11

ZyWALL 50 Internet Security Gateway

Chapter 5

IP Static Route Setup

This chapter shows you how to configure static routes with your ZyWALL.

Static routes tell the ZyWALL routing information that it cannot learn automatically through other means.

This can arise in cases where RIP is disabled on the LAN.

Each remote node specifies only the network to which the gateway is directly connected, and the ZyWALL

has no knowledge of the networks beyond. For instance, the ZyWALL knows about network N2 in the

following diagram through remote node Router 1. However, the ZyWALL is unable to route a packet to

network N3 because it doesn’t know that there is a route through the same remote node Router 1 (via

gateway Router 2). The static routes are for you to tell the ZyWALL about the networks beyond the remote

nodes.

Figure 5-1 Example of Static Routing Topology

IP Static Route Setup 5-1

ZyWALL 50 Internet Security Gateway

5.1 IP Static Route Setup

You configure IP static routes in menu 12. 1 by selecting one of the IP static routes as shown next. Enter 12

from the main menu.

Menu 12 - IP Static Route Setup

1. ________

2. ________

3. ________

4. ________

5. ________

6. ________

7. ________

8. ________

Enter selection number:

Figure 5-2 Menu 12 — IP Static Route Setup

Now, enter the index number of one of the static routes you want to configure.

Menu 12.1 - Edit IP Static Route

Route #: 1
Route Name= ?
Active= No
Destination IP Address= ?
IP Subnet Mask= ?
Gateway IP Address= ?
Metric= 2
Private= No

Press ENTER to CONFIRM or ESC to CANCEL:

Figure 5-3 Menu 12. 1 — Edit IP Static Route

`The following table describes the IP Static Route Menu fields.

5-2 IP Static Route Setup

ZyWALL 50 Internet Security Gateway

Table 5-1 IP Static Route Menu Fields

FIELD DESCRIPTION

Route # This is the index number of the static route that you chose in menu 12.

Route Name Enter a descriptive name for this route. This is for identification purposes only.

Active This field allows you to activate/deactivate this static route.

Destination IP
Address

IP Subnet Mask Enter the IP subnet mask for this destination.

Gateway IP
Address

Metric Metric represents the “cost” of transmission for routing purposes. IP routing uses hop

Private This parameter determines if the ZyWALL will include the route to this remote node in

Once you have completed filling in this menu, press [ENTER] at the message “Press ENTER to
Confirm…” to save your configuration, or press [ESC] to cancel.

This parameter specifies the IP network address of the final destination. Routing is
always based on network number. If you need to specify a route to a single host, use a
subnet mask of 255.255.255.255 in the subnet mask field to force the network number
to be identical to the host ID.

Enter the IP address of the gateway. The gateway is an immediate neighbor of your
ZyWALL that will forward the packet to the destination. On the LAN, the gateway must
be a router on the same segment as your ZyWALL; over the WAN, the gateway must
be the IP address of one of the Remote Nodes.

count as the measurement of cost, with a minimum of 1 for directly connected
networks. Enter a number that approximates the cost for this link. The number need
not be precise, but it must be between 1 and 15. In practice, 2 or 3 is usually a good
number.

its RIP broadcasts. If set to Yes, this route is kept private and not included in RIP
broadcast. If No, the route to this remote node will be propagated to other hosts
through RIP broadcasts.

IP Static Route Setup 5-3

ZyWALL 50 Internet Security Gateway

Chapter 6

Network Address Translation (NAT)

This chapter discusses how to configure NAT on the ZyWALL.

6.1 Introduction

NAT (Network Address Translation - NAT, RFC 1631) is the translation of the IP address of a host in a

packet, e.g., the source address of an outgoing packet, used within one network to a different IP address

known within another network.

6.1.1 NAT Definitions

Inside/outside denotes where a host is located relative to the ZyWALL, e.g., the workstations of your

subscribers are the inside hosts, while the web servers on the Internet are the outside hosts.

Global/local denotes the IP address of a host in a packet as the packet traverses a router, e.g., the local

address refers to the IP address of a host when the packet is in the local network, while the global address

refers to the IP address of the host when the same packet is travelling in the WAN side.

Note that inside/outside refers to the location of a host, while global/local refers to the IP address of a host

used in a packet. Thus, an inside local address (ILA) is the IP address of an inside host in a packet when

the packet is still in the local network, while an inside global address (IGA) is the IP address of the same

inside host when the packet is on the WAN side. The following table summarizes this information.

Table 6-1 NAT Definitions

TERM DESCRIPTION

Inside This refers to the host on the LAN.

Outside This refers to the host on the WAN.

Local This refers to the packet address (source or destination) as the packet travels on the LAN.

Global This refers to the packet address (source or destination) as the packet travels on the

NAT 6-1

ZyWALL 50 Internet Security Gateway

Table 6-1 NAT Definitions

TERM DESCRIPTION

WAN.

NAT never changes the IP address (either local or global) of an outside host.

6.1.2 What NAT Does

In the simplest form, NAT changes the source IP address in a packet received from a subscriber (the inside

local address) to another (the inside global address) before forwarding the packet to the WAN side. When

the response comes back, NAT translates the destination address (the inside global address) back the inside

local address before forwarding it to the original inside host. Note that the IP address (either local or global)

of an outside host is never changed.

The global IP addresses for the inside hosts can be either static or dynamically assigned by the ISP. In

addition, you can designate servers, e.g., a web server and a telnet server, on your local network and make

them accessible to the outside world. If you do not define any servers (for Many-to-One and Many-to-Many

Overload mapping – see Table 6-2), NAT offers the additional benefit of firewall protection. If no server is

defined in these cases, all incoming inquiries will be filtered out by your ZyWALL, thus preventing

intruders from probing your network. For more information on IP address translation, refer to RFC 1631,

The IP Network Address Translator (NAT).

6.1.3 How NAT Works

Each packet has two addresses – a source address and a destination address. For outgoing packets, the ILA

(Inside Local Address) is the source address on the LAN, and the IGA (Inside Global Address) is the source

address on the WAN. For incoming packets, the ILA is the destination address on the LAN, and the IGA is

the destination address on the WAN. NAT maps private (local) IP addresses to globally unique ones

required for communication with hosts on other networks. It replaces the original IP source address (and

TCP or UDP source port numbers for Many-to-One and Many-to-Many Overload NAT mapping) in each

packet and then forwards it to the Internet. The ZyWALL keeps track of the original addresses and port

numbers so incoming reply packets can have their original values restored. The following figure illustrates

this.

6-2 NAT

ZyWALL 50 Internet Security Gateway

Figure 6-1 How NAT Works

6.1.4 NAT Application

The following figure illustrates a possible NAT application, where three inside LANs (logical LANs using

IP Alias) behind the ZyWALL can communicate with three distinct WAN networks. More examples follow

at the end of this chapter.

NAT 6-3

ZyWALL 50 Internet Security Gateway

Figure 6-2 NAT Application With IP Alias

6.1.5 NAT Mapping Types

NAT supports five types of IP/port mapping. They are:

1. One to One: In One-to-One mode, the ZyWALL maps one local IP address to one global IP address.

2. Many to One: In Many-to-One mode, the ZyWALL maps multiple local IP addresses to one global IP

address. This is equivalent to SUA (i.e., PAT, port address translation), ZyXEL’s Single User Account

feature that previous ZyXEL routers supported (the SUA Only option in today’s routers).

6-4 NAT

ZyWALL 50 Internet Security Gateway

3. Many to Many Overload: In Many-to-Many Overload mode, the ZyWALL maps the multiple local IP

addresses to shared global IP addresses.

4. Many to Many No Overload:

In Many-to-Many No Overload mode, the ZyWALL maps the each

local IP addresses to unique global IP addresses.

5. Server: This type allows you to specify inside servers of different services behind the NAT to be

accessible to the outside world.

Port numbers do not change for One-to-One and Many-to-Many-No Overload NAT mapping

types.

The following table summarizes these types.

Table 6-2 NAT Mapping Types

TYPE IP MAPPING SMT ABBREVIATION

One-to-One ILA1ÅÆ IGA1 1:1

Many-to-One (SUA/PAT) ILA1ÅÆ IGA1

ILA2ÅÆ IGA1

…

Many-to-Many Overload ILA1ÅÆ IGA1

ILA2ÅÆ IGA2

ILA3ÅÆ IGA1

ILA4ÅÆ IGA2

…

Many-to-Many No Overload ILA1ÅÆ IGA1

ILA2ÅÆ IGA2

ILA3ÅÆ IGA3

…

Server Server 1 IPÅÆ IGA1

Server 2 IPÅÆ IGA1

Server 3 IPÅÆ IGA1

M:1

M:M Ov

M:M No Ov

Server

NAT 6-5

ZyWALL 50 Internet Security Gateway

6.2 Using NAT

6.2.1 SUA (Single User Account) Versus NAT

SUA (Single User Account) is a ZyNOS implementation of a subset of NAT that supports two types of

mapping, Many-to-One and Server. See section 6.3.1 for a detailed description of the NAT set for SUA.

The ZyWALL also supports Full Feature NAT to map multiple global IP addresses to multiple private

LAN IP addresses of clients or servers using mapping types as outlined in Table 6-2.

1. Choose SUA Only if you have just one public WAN IP address for your ZyWALL.

2. Choose Full Feature if you have multiple public WAN IP addresses for your ZyWALL.

6.2.2 Applying NAT

You apply NAT via menus 4 or 11.3 as displayed next. The next figure shows you how to apply NAT for

Internet access in menu 4. Enter 4 from the main menu to go to Menu 4 - Internet Access Setup.

Menu 4 - Internet Access Setup

ISP's Name= ChangeMe
Encapsulation= Ethernet

Service Type= Standard
My Login= N/A
My Password= N/A
Login Server IP= N/A

IP Address Assignment= Dynamic

IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Address= N/A

Network Address Translation= SUA Only

Press ENTER to Confirm or ESC to Cancel:

Figure 6-3 Menu 4 — Applying NAT for Internet Access

The following figure shows how you apply NAT to the remote node in menu 11.1.

Step 1. Enter 11 from the main menu.

6-6 NAT

ZyWALL 50 Internet Security Gateway

Step 2. Move the cursor to the Edit IP field, press [SPACE BAR] to select Yes and then press

Menu 11.3 - Remote Node Network Layer Options

IP Address Assignment= Dynamic
IP Address= N/A
IP Subnet Mask= N/A
Gateway IP Addr= N/A

Network Address Translation= SUA Only
Metric= N/A
Private= N/A
RIP Direction= None

Version= N/A

Multicast= None

Enter here to CONFIRM or ESC to CANCEL:

Press Space Bar to Toggle.

[ENTER] to bring up Menu 11.3 - Remote Node Network Layer Options.

Figure 6-4 Menu 11.3 — Applying NAT to the Remote Node

The following table describes the options for Network Address Translation.

Table 6-3 Applying NAT in Menus 4 & 11.3

FIELD OPTIONS DESCRIPTION

Network
Address
Translation

Full
Feature

When you select this option the SMT will use Address Mapping Set 1
(menu 15.1 - see section 6.3.1 for further discussion). You can configure
any of the mapping types described in Table 6-2. Choose Full Feature if
you have multiple public WAN IP addresses for your ZyWALL.

None

SUA Only

NAT is disabled when you select this option.

When you select this option the SMT will use Address Mapping Set 255
(menu 15.1 - see section 6.3.1). Choose SUA Only if you have just one
public WAN IP address for your ZyWALL.

NAT 6-7

ZyWALL 50 Internet Security Gateway

6.3 NAT Setup

Use the Address Mapping Sets menus and submenus to create the mapping table used to assign global

addresses to computers on the LAN. You can see two NAT Address Mapping sets in menu 15.1. You can

only configure Set 1. Set 255 is used for SUA. When you select Full Feature in menu 4 or 11.3, the

SMT will use Set 1, which supports all mapping types as outlined in Table 6-2. When you select SUA

Only, the SMT will use the pre-configured Set 255 (read only).

A server set is a list of LAN side servers mapped to external ports. To use this set (one set for the

ZyWALL 50), a server rule must be set up inside the NAT Address Mapping set. Please see section 6.4 for

further information on these menus. To configure NAT, enter 15 from the main menu to bring up the

following screen.

Menu 15 — NAT Setup

1. Address Mapping Sets

2. Server Set

Enter Menu Selection Number:

Figure 6-5 Menu 15 — NAT Setup

6.3.1 Address Mapping Sets

Enter 1 to bring up Menu 15.1 — Address Mapping Sets.

Menu 15.1 — Address Mapping Sets

1. NAT_SET

255. SUA (read only)

Enter Menu Selection Number:

Figure 6-6 Menu 15.1 — Address Mapping Sets

6-8 NAT