Zyxel ZW50 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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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

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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

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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