ZyXEL Communications ZYWALL10 User Manual

ZyWALL 10

Internet Security Gateway

User’s Guide

Version 3.24

April 2001

ZyWALL 10 Internet Security Gateway

Copyright

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 so ftware 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

Trademarks mentioned in this publication are used for identification purposes only and may be properties of their respective owners.

ii Copyright

ZyWALL 10 Internet Security Gateway

Federal Communications Commission

(FCC) Interference Statement

This device complies with Part 15 of FCC rules. Operation is subj ect 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: Reorient or relocate the receiving antenna. Increase the separation between the equipment and the receiver. Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. 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. Notice 2 Use of Shielded RS-232 cables is required to ensure compliance with FCC Part 15, and it is the responsibility of the user to provide and use shielded RS-232 cables.

FCC iii

ZyWALL 10 Internet Security Gateway

Information for Canadian Users

The Industry Canada label identifies certifi ed equi pme nt. This certification means that the equipment meets certain telecommunications network protective, operation, and safety requirements. The Industry Canada 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 the 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 connectio ns themselves, but should contact the appropri ate 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.

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ZyWALL 10 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 10

(reference to the specification under which conformity is declared)

is in conformity with

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

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

Voltage dips, short interruptions and voltage variations immunity tests

Version

1994

1995

1996

1993 1994

Declaration of Conformity v

ZyWALL 10 Internet Security Gateway

vi CE

ZyWALL 10 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 ri ghts, and you may also have other rig ht s that vary from country to country.

Online Registration

Don’t forge t to register your ZyXEL product (fast, easy online regi stration at www.zyxel.com) for free future product updates and information.

ZyXEL Limited Warranty vii

ZyWALL 10 Internet Security Gateway

Customer Support

When you contact your customer support representative please have the following information ready:

♦ ZyWALL Model and serial number. ♦ Information in Menu 24.2.1 —System Information. ♦ Warranty Information. ♦ Date you received your ZyWALL. ♦ Brief description of the problem and the steps you took to solve it.

Method

Region

Worldwide

North

America

Scandinavia

Austria

Germany

EMAIL — Support Telephone Web Site

EMAIL — Sales Fax FTP Site

support@zyxel.com.tw support@europe.zyxel.com

sales@zyxel.com.tw +886-3-578-2439 ftp.europe.zyxel.com support@zyxel.com +1-714-632-0882

sales@zyxel.com +1-714-632-0858 ftp.zyxel.com support@zyxel.dk +45-3955-0700 www.zyxel.dk

sales@zyxel.dk +45-3955-0707 ftp.zyxel.dk support@zyxel.at +43-1-4948677-0

sales@zyxel.at

support@zyxel.de

sales@zyxel.de +49-2405-6909-99 ftp.europe.zyxel.com

+886-3-578-3942 www.zyxel.com

800-255-4101

0810-1-ZyXEL 0810-1-99935

+43-1-4948678

+49-2405-6909-0 0180-5213247

Tech Support hotline

0180-5099935

RMA/Repair hotline

www.europe.zyxel.com

www.zyxel.com

www.zyxel.at

ftp.zyxel.at

Note: for Austrian users with *.at domain only!

www.zyxel.de

Regular Mail

ZyXEL Communications

Corp., 6 Innovation Road II,

Science-Based Industrial

Park, HsinChu, Taiwan.

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-5 214 6

Wuerselen, German y.

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

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

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

ZyXEL Limited Warranty .......................................................................................................................vii

Customer Support.................................................................................................................................... viii

Table of Contents ....................................................................................................................................... ix

List of Figures.......................................................................................................................................... xvii

List of Tables ..........................................................................................................................................xxiii

Preface.................................................................................................................................................... xxvii

Getting Started....................................................................................................................................................I

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

1.1 The ZyWALL 10 Internet Security Gateway............................................................................. 1-1

1.2 Features of The ZyWALL 10..................................................................................................... 1-1

1.3 Applications for ZyWALL 10.................................................................................................... 1-3

1.3.1 Broadband Internet Access via Cable or xDSL Modem.....................................................1-3

Chapter 2 Hardware Installation & Initial Setup.................................................................................2-1

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

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

2.2 ZyWALL 10 Rear Panel and Connections................................................................................. 2-2

2.3 Additional Installation Requirements.........................................................................................2-3

2.4 Turn On Your ZyWALL............................................................................................................ 2-4

2.5 Navigating the SMT Interface.................................................................................................... 2-4

2.5.1 Main Menu......................................................................................................................... 2-6

2.5.2 System Management Terminal Interface Summary ........................................................... 2-7

2.5.3 SMT Menus at a Glance..................................................................................................... 2-8

2.6 Changing the System Password..................................................................................................2-9

2.6.1 Resetting the ZyWALL...................................................................................................... 2-9

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2.7 General Setup..............................................................................................................................2-9

2.7.1 Dynamic DNS...................................................................................................................2-10

2.7.2 Procedure For Configuring Menu 1..................................................................................2-10

2.7.3 Configuring Dynamic DNS...............................................................................................2-11

2.8 WAN Setup...............................................................................................................................2-12

2.9 LAN Setup ................................................................................................................................2-13

2.9.1 LAN Port Filter Setup.......................................................................................................2-14

Chapter 3 Internet Access........................................................................................................................3-1

3.1 TCP/IP and DHCP for LAN .......................................................................................................3-1

3.1.1 Factory LAN Defaults......................................................................................................... 3-1

3.1.2 DHCP Configuration...........................................................................................................3-1

3.1.3 IP Address and Subnet Mask ..............................................................................................3-2

3.1.4 Private IP Addresses ...........................................................................................................3-2

3.1.5 RIP Setup ............................................................................................................................3-3

3.1.6 IP Multicast......................................................................................................................... 3-3

3.1.7 IP Alias................................................................................................................................3-4

3.2 TCP/IP and DHCP Ethernet Setup..............................................................................................3-4

3.2.1 IP Alias Setup......................................................................................................................3-7

3.3 Internet Access Setup..................................................................................................................3-8

3.3.1 Ethernet Encapsulation........................................................................................................3-8

3.3.2 PPTP Encapsulation..........................................................................................................3-10

3.3.3 Configuring the PPTP Client.............................................................................................3-10

3.3.4 PPPoE Encapsulation........................................................................................................3-11

3.4 Basic Setup Complete...............................................................................................................3-13

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............................................................................................................4-4

4.2 Editing TCP/IP Options (with Ethernet Encapsulation)..............................................................4-6

4.2.1 Editing TCP/IP Options (with PPTP Encapsulation)..........................................................4-7

4.2.2 Editing TCP/IP Options (with PPPoE Encapsulation)........................................................4-9

4.3 Remote Node Filter.....................................................................................................................4-9

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

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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................................................................................................................. 6-1

6.1.3 How NAT works................................................................................................................ 6-2

6.1.4 NAT Mapping Types..........................................................................................................6-3

6.1.5 SUA (Single User Account) Versus NAT.......................................................................... 6-4

6.1.6 NAT Application................................................................................................................ 6-4

6.2 SMT Menus ................................................................................................................................ 6-5

6.2.1 Applying NAT in the SMT Menus..................................................................................... 6-5

6.2.2 Configuring NAT............................................................................................................... 6-7

6.2.3 Address Mapping Sets and NAT Server Sets:.................................................................... 6-7

6.3 NAT Server Sets....................................................................................................................... 6-12

6.3.1 Multiple Servers behind NAT .......................................................................................... 6-13

6.3.2 Configuring a Server behind NAT ................................................................................... 6-13

6.4 Examples..................................................................................................................................6-15

6.4.1 Internet Access Only........................................................................................................ 6-15

6.4.2 Example 2: Internet Access with an Inside Server........................................................... 6-16

6.4.3 Example 3: General Case ................................................................................................. 6-17

6.4.4 Example 4: NAT Unfriendly Application Programs........................................................6-20

Advanced Management....................................................................................................................................III

Chapter 7 Filter Configuration............................................................................................................... 7-1

7.1 About Filtering........................................................................................................................... 7-1

7.1.1 The Filter Structure of the ZyWALL..................................................................................7-2

7.2 Configuring a Filter Set.............................................................................................................. 7-4

7.2.1 Filter Rules Summary Menu............................................................................................... 7-6

7.2.2 Configuring a Filter Rule....................................................................................................7-7

7.2.3 TCP/IP Filter Rule.............................................................................................................. 7-7

7.2.4 Generic Filter Rule........................................................................................................... 7-11

7.3 Example Filter..........................................................................................................................7-13

7.4 Filter Types and NAT............................................................................................................... 7-15

7.5 Firewall.....................................................................................................................................7-16

7.6 Applying a Filter and Factory Defaults.................................................................................... 7-16

7.6.1 LAN traffic....................................................................................................................... 7-16

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7.6.2 Remote Node Filters..........................................................................................................7-17

Chapter 8 SNMP Configuration..............................................................................................................8-1

8.1 About SNMP...............................................................................................................................8-1

8.2 Configuring SNMP.....................................................................................................................8-1

Chapter 9 System Information & Diagnosis..........................................................................................9-1

9.1 System Status..............................................................................................................................9-1

9.2 System Information and Console Port Speed..............................................................................9-3

9.2.1 System Information.............................................................................................................9-4

9.2.2 Console Port Speed.............................................................................................................9-5

9.3 Log and Trace.............................................................................................................................9-5

9.3.1 Viewing Error Log..............................................................................................................9-5

9.3.2 UNIX Syslog............................................................................................................... ........9-6

9.3.3 Call-Triggering Packet......................................................................................................9-10

9.4 Diagnostic.................................................................................................................................9-10

9.4.1 WAN DHCP .....................................................................................................................9-11

Chapter 10 Firmware and Configuration File Maintenance..............................................................10-1

10.1 Filename conventions................................................................................................................10-1

10.1.1 Firmware Development.....................................................................................................10-2

10.2 Backup Configuration...............................................................................................................10-2

10.2.1 Example: Backup Configuration Using HyperTerminal...................................................10-3

10.2.2 Backup Configuration Using Telnet..................................................................................10-3

10.3 Restore Configuration...............................................................................................................10-4

10.3.1 Example: Restore Configuration Using HyperTerminal...................................................10-4

10.4 Upload Firmware ......................................................................................................................10-5

10.4.1 Uploading the Router Firmware........................................................................................10-5

10.4.2 Example: Xmodem Upload Using HyperTerminal...........................................................10-6

10.4.3 Uploading Router Configuration File................................................................................10-6

10.5 TFTP File Transfer....................................................................................................................10-7

10.5.1 Example: TFTP Command................................................................................................10-8

10.6 FTP File Transfer......................................................................................................................10-9

10.6.1 Using the FTP command from the DOS Prompt.............................................................10-11

Chapter 11 System Maintenance & Information.................................................................................11-1

11.1 Command Interpreter Mode......................................................................................................11-1

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11.2 Call Control Support ................................................................................................................ 11-2

11.2.1 Budget Management......................................................................................................... 11-2

11.2.2 Call History ...................................................................................................................... 11-3

11.3 Time and Date Setting.............................................................................................................. 11-4

How often does the ZyWALL update the time?...............................................................................11-6

11.4 Remote Management Setup...................................................................................................... 11-7

11.5 Boot Commands....................................................................................................................... 11-8

Chapter 12 Telnet Configuration and Capabilities ............................................................................. 12-1

12.1 About Telnet Configuration......................................................................................................12-1

12.2 Telnet Under NAT.................................................................................................................... 12-1

12.3 Telnet Capabilities.................................................................................................................... 12-1

12.3.1 Single Administrator ........................................................................................................ 12-1

12.3.2 System Timeout................................................................................................................ 12-2

12.4 Telnet Behind the Firewall.......................................................................................................12-2

Firewall and Content Filters......................................................................................................................... 13-1

Chapter 13 What is a Firewall?............................................................................................................ 13-1

13.1 Types of Firewalls.................................................................................................................... 13-1

13.1.1 Packet Filtering Firewalls.................................................................................................13-1

13.1.2 Application-level Firewalls .............................................................................................. 13-1

13.1.3 Stateful Inspection Firewalls............................................................................................ 13-2

13.2 Introduction to ZyXEL’s Firewall............................................................................................ 13-2

13.3 Denial of Service...................................................................................................................... 13-3

13.3.1 Basics................................................................................................................................13-3

13.3.2 Types of DoS attacks........................................................................................................ 13-4

13.4 Stateful Inspection.................................................................................................................... 13-6

13.4.1 Stateful Inspection Process............................................................................................... 13-7

13.4.2 Stateful Inspection & the ZyWALL................................................................................. 13-8

13.4.3 TCP Security .................................................................................................................... 13-8

13.4.4 UDP/ICMP Security......................................................................................................... 13-9

13.4.5 Upper Layer Protocols...................................................................................................... 13-9

13.5 Guidelines For Enhancing Security With Your Firewall..........................................................13-9

13.5.1 Security In General......................................................................................................... 13-10

Chapter 14 Introducing the ZyWALL Firewall .................................................................................. 14-1

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14.1 SMT Menus...............................................................................................................................14-1

14.1.1 View Firewall Log............................................................................................................14-2

14.1.2 Attack Types.....................................................................................................................14-2

14.2 The Big Picture - Filtering, Firewall and NAT.........................................................................14-5

14.3 Packet Filtering Vs Firewall......................................................................................................14-6

14.3.1 Packet Filtering:................................................................................................................14-6

14.3.2 Firewall .............................................................................................................................14-7

Chapter 15 Introducing the ZyWALL Web Configurator..................................................................15-1

15.1 Web Configurator Login and Welcome Screens.......................................................................15-1

15.2 Enabling the Firewall................................................................................................................15-3

15.3 E-mail........................................................................................................................................15-3

15.3.1 What are Alerts?................................................................................................................15-3

15.3.2 What are Logs? ................................................................................................................. 15-4

15.3.3 SMTP Error Messages ......................................................................................................15-6

15.3.4 Example E-mail Log.........................................................................................................15-6

15.4 Attack Alert...............................................................................................................................15-7

15.4.1 Threshold Values: .............................................................................................................15-7

15.4.2 Half-Open Sessions ...........................................................................................................15-8

Chapter 16 Creating Custom Rules......................................................................................................16-1

16.1 Rules Overview.........................................................................................................................16-1

16.2 Rule Logic Overview................................................................................................................16-1

16.2.1 Rule Checklist...................................................................................................................16-1

16.2.2 Security Ramifications......................................................................................................16-2

16.2.3 Key Fields For Configuring Rules....................................................................................16-2

16.3 Connection Direction................................................................................................................16-3

16.3.1 LAN to WAN Rules..........................................................................................................16-3

16.3.2 WAN to LAN Rules..........................................................................................................16-3

16.4 Rule Summary...........................................................................................................................16-4

16.5 Predefined Services...................................................................................................................16-7

16.5.1 Creating/Editing Firewall Rules......................................................................................16-10

16.5.2 Source and Destination Addresses.................................................................................. 16-12

16.6 Timeout...................................................................................................................................16-14

16.6.1 Factors Influencing Choices for Timeout Values............................................................16-14

Chapter 17 Custom Ports.......................................................................................................................17-1

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17.1 Introduction..............................................................................................................................17-1

17.2 Creating/Editing A Custom Port .............................................................................................. 17-3

Chapter 18 Logs..................................................................................................................................... 18-1

18.1 Log Screen................................................................................................................................18-1

Chapter 19 Example Firewall Rules.....................................................................................................19-1

19.1 Examples.................................................................................................................................. 19-1

19.1.1 Example 1: Firewall Rule To Allow Web Service From The Internet.............................19-1

19.1.2 Example 2: Small Office With Mail, FTP and Web Servers ............................................ 19-6

19.1.3 Example 3: DHCP Negotiation and Syslog Connection from the Internet..................... 19-12

Chapter 20 Content Filtering................................................................................................................ 20-1

20.1 Categories................................................................................................................................. 20-1

20.1.1 Restrict Web Features.......................................................................................................20-1

20.1.2 Filter List.......................................................................................................................... 20-1

20.1.3 Days and Times................................................................................................................ 20-1

20.2 Update List...............................................................................................................................20-3

20.3 Exempting Computers.............................................................................................................. 20-4

20.4 Customizing..............................................................................................................................20-5

20.5 Keywords ................................................................................................................................. 20-6

20.6 Log Records ............................................................................................................................. 20-7

Troubleshooting, Appendices, Glossary and Index...........................................................................................V

Chapter 21 Troubleshooting..................................................................................................................21-1

21.1 Problems Starting Up the ZyWALL......................................................................................... 21-1

21.2 Problems with the LAN Interface............................................................................................. 21-2

21.3 Problems with the WAN interface............................................................................................21-2

21.4 Problems with Internet Access................................................................................................. 21-3

21.5 Problems with the Firewall....................................................................................................... 21-3

Appendix A PPPoE.....................................................................................................................................A

Appendix B PPTP......................................................................................................................................C

Appendix C Hardware Specifications.......................................................................................................E

Appendix D Important Safety Instructions..............................................................................................F

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Appendix E Firewall CLI Commands......................................................................................................G

Appendix F Power Adapter Specifications.............................................................................................. L

Glossary of Terms.......................................................................................................................................N

Index............................................................................................................................................................Y

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

Figure 2-2 ZyWALL 10 Rear Panel and Connections.................................................................................... 2-2

Figure 2-3 Initial Screen................................................................................................................................. 2-4

Figure 2-4 Password Screen........................................................................................................................... 2-4

Figure 2-5 ZyWALL 10 Main Menu.............................................................................................................. 2-6

Figure 2-6 SMT Menus at a Glance............................................................................................................... 2-8

Figure 2-7 Menu 23 — System Password...................................................................................................... 2-9

Figure 2-8 Menu 1 — General Setup........................................................................................................... 2-10

Figure 2-9 Configure Dynamic DNS............................................................................................................2-11

Figure 2-10 Menu 2 — WAN Setup............................................................................................................. 2-13

Figure 2-11 Menu 3 — LAN Setup.............................................................................................................. 2-14

Figure 2-12 Menu 3.1 — LAN Port Filter Setup......................................................................................... 2-14

Figure 3-1 Physical Network..........................................................................................................................3-4

Figure 3-2 Partitioned Logical Networks....................................................................................................... 3-4

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

Figure 3-4 Menu 3.2 — TCP/IP and DHCP Ethernet Setup.......................................................................... 3-5

Figure 3-5 Menu 3.2.1 — IP Alias Setup....................................................................................................... 3-7

Figure 3-6 Menu 4 — Internet Access Setup (Ethernet)................................................................................ 3-9

Figure 3-7 Internet Access Setup (PPTP) .....................................................................................................3-11

Figure 3-8 Internet Access Setup (PPPoE) .................................................................................................. 3-12

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

Figure 4-2 Menu 11.1 — Remote Node Profile for PPPoE Encapsulation.................................................... 4-3

Figure 4-3 Menu 11.1 — Remote Node Profile for PPTP Encapsulation...................................................... 4-5

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Figure 4-4 Menu 11.3 — Remote Node Network Layer Options...................................................................4-6

Figure 4-5 Menu 11.3 — Remote Node Network Layer Options...................................................................4-8

Figure 4-6 Menu 11.5 — Remote Node Filter (Ethernet Encapsulation) .....................................................4-10

Figure 4-7 Menu 11.5 — Remote Node Filter (PPPoE or PPTP Encapsulation) ......................................... 4-10

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...........................................................................................................................6-2

Figure 6-2 NAT Application...........................................................................................................................6-5

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

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

Figure 6-5 Menu 15 — NAT Setup.................................................................................................................6-7

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

Figure 6-7 Menu 15.1.255 — SUA Address Mapping Rules.........................................................................6-8

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

Figure 6-9 Menu 15.1.1.1 — Editing an Individual Rule in a Set................................................................6-11

Figure 6-10 Multiple Servers Behind NAT...................................................................................................6-13

Figure 6-11 Menu 15.2 — NAT Server Setup ..............................................................................................6-14

Figure 6-12 NAT Example 1.........................................................................................................................6-15

Figure 6-13 Menu 4 — Internet Access & NAT Example............................................................................6-15

Figure 6-14 NAT Example 2.........................................................................................................................6-16

Figure 6-15 Menu 15.2 — Specifying an Inside Server ...............................................................................6-16

Figure 6-16 NAT Example 3.........................................................................................................................6-17

Figure 6-17 Example 3: Menu 11.3..............................................................................................................6-18

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

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

Figure 6-20 Example 3: Menu 15.2..............................................................................................................6-19

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Figure 6-21 NAT Example 4........................................................................................................................ 6-20

Figure 6-22 Example 4: Menu 15.1.1.1 — Address Mapping Rule............................................................. 6-21

Figure 6-23 Example 4: Menu 15.1.1 — Address Mapping Rules.............................................................. 6-21

Figure 7-1 Outgoing Packet Filtering Process ............................................................................................... 7-1

Figure 7-2 Filter Rule Process........................................................................................................................ 7-3

Figure 7-4 Menu 21 — Filter and Firewall Setup.......................................................................................... 7-4

Figure 7-5 Menu 21.1 — Filter Set Configuration......................................................................................... 7-4

Figure 7-6 NetBIOS_WAN Filter Rules Summary........................................................................................ 7-5

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

Figure 7-8 TEL_FTP_WEB_WAN Filter Rules Summary............................................................................ 7-5

Figure 7-9 Menu 21.1.1.1 — TCP/IP Filter Rule........................................................................................... 7-7

Figure 7-10 Executing an IP Filter............................................................................................................... 7-10

Figure 7-11 Menu 21.4.1.1 — Generic Filter Rule.......................................................................................7-11

Figure 7-12 Telnet Filter Example............................................................................................................... 7-13

Figure 7-13 Example Filter — Menu 21.1.1.1............................................................................................. 7-14

Figure 7-14 Example Filter Rules Summary — Menu 21.1.3 ..................................................................... 7-15

Figure 7-15 Protocol and Device Filter Sets................................................................................................ 7-16

Figure 7-16 Filtering LAN Traffic............................................................................................................... 7-17

Figure 7-17 Filtering Remote Node Traffic ................................................................................................. 7-17

Figure 8-1 Menu 22 — SNMP Configuration................................................................................................ 8-1

Figure 9-1 Menu 24 — System Maintenance ................................................................................................ 9-1

Figure 9-2 Menu 24.1 — System Maintenance — Status..............................................................................9-2

Figure 9-3 Menu 24.2 — System Information and Console Port Speed........................................................ 9-3

Figure 9-4 Menu 24.2.1 — System Maintenance — Information................................................................. 9-4

Figure 9-5 Menu 24.2.2 — System Maintenance — Change Console Port Speed....................................... 9-5

Figure 9-6 Menu 24.3 — System Maintenance — Log and Trace ................................................................ 9-6

Figure 9-7 Examples of Error and Information Messages ............................................................................. 9-6

List of Figures xix

ZyWALL 10 Internet Security Gateway

Figure 9-8 Menu 24.3.2 — System Maintenance — UNIX Syslog................................................................9-6

Figure 9-9 Call-Triggering Packet Example.................................................................................................9-10

Figure 9-10 Menu 24.4 — System Maintenance — Diagnostic...................................................................9-11

Figure 9-11 WAN & LAN DHCP.................................................................................................................9-12

Figure 10-1 System Maintenance — Backup Configuration........................................................................10-2

Figure 10-2 Example: Backup Configuration...............................................................................................10-3

Figure 10-4 Telnet into Menu 24.5 — Backup Configuration......................................................................10-3

Figure 10-5 System Maintenance — Restore Configuration........................................................................10-4

Figure 10-6 Example: Restore Configuration...............................................................................................10-4

Figure 10-8 Telnet into Menu 24.6 Restore Configuration...........................................................................10-5

Figure 10-9 Menu 24.7 — System Maintenance — Upload Firmware........................................................10-5

Figure 10-10 Menu 24.7.1 — System Maintenance — Upload Router Firmware .......................................10-6

Figure 10-11 Example: Xmodem Upload.....................................................................................................10-6

Figure 10-12 Menu 24.7.2 — System Maintenance — Upload Router Configuration File .........................10-7

Figure 10-13 Telnet into Menu 24.7.1........................................................................................................10-10

Figure 10-14 Telnet into Menu 24.7.2 — System Maintenance.................................................................10-10

Figure 10-15 FTP Session Example ...........................................................................................................10-11

Figure 11-1 Command Mode in Menu 24.....................................................................................................11-1

Figure 11-2 Valid Commands.......................................................................................................................11-1

Figure 11-3 Call Control...............................................................................................................................11-2

Figure 11-4 Budget Management..................................................................................................................11-2

Figure 11-5 Call History...............................................................................................................................11-4

Figure 11-6 Menu 24 — System Maintenance .............................................................................................11-5

Figure 11-7 Menu 24.10 System Maintenance — Time and Date Setting....................................................11-5

Figure 11-8 Menu 24.11 — Remote Management Control ..........................................................................11-7

Figure 11-9 Option to Enter Debug Mode....................................................................................................11-8

Figure 11-10 Boot Module Commands.........................................................................................................11-9

xx List of Figures

ZyWALL 10 Internet Security Gateway

Figure 12-1 Telnet Configuration on a TCP/IP Network............................................................................. 12-1

Figure 13-1 ZyWALL Firewall Application ................................................................................................ 13-3

Figure 13-2 Three-Way Handshake ............................................................................................................. 13-5

Figure 13-3 SYN Flood................................................................................................................................ 13-5

Figure 13-4 Smurf Attack............................................................................................................................ 13-6

Figure 13-5 Stateful Inspection.................................................................................................................... 13-7

Figure 14-1 SMT Main Menu...................................................................................................................... 14-1

Figure 14-2 Menu 21 — Filter and Firewall Setup...................................................................................... 14-1

Figure 14-3 Menu 21.2 — Firewall Setup................................................................................................... 14-2

Figure 14-4 View Firewall Log.................................................................................................................... 14-4

Figure 14-5 Big Picture — Filtering, Firewall and NAT.............................................................................. 14-6

Figure 15-1 Login screen as seen in Netscape............................................................................................. 15-1

Figure 15-2 ZyWALL Web Configurator Welcome Screen......................................................................... 15-2

Figure 15-3 Enabling the Firewall ............................................................................................................... 15-3

Figure 15-4 E-mail Screen........................................................................................................................... 15-4

Figure 15-5 E-mail Log................................................................................................................................ 15-7

Figure 15-6 Attack Alert.............................................................................................................................. 15-9

Figure 16-1 LAN to WAN Traffic................................................................................................................ 16-3

Figure 16-2 WAN to LAN Traffic................................................................................................................ 16-4

Figure 16-3 Firewall Rules Summary — First Screen................................................................................. 16-5

Figure 16-4 Creating/Editing A Firewall Rule........................................................................................... 16-10

Figure 16-5 Adding/Editing Source and Destination Addresses................................................................ 16-12

Figure 16-6 Timeout Screen....................................................................................................................... 16-14

Figure 17-1 Custom Ports............................................................................................................................ 17-1

Figure 17-2 Creating/Editing A Custom Port .............................................................................................. 17-3

Figure 18-1 Log Screen................................................................................................................................ 18-1

Figure 19-1 Activate The Firewall............................................................................................................... 19-2

List of Figures xxi

ZyWALL 10 Internet Security Gateway

Figure 19-2 Example 1: E-mail Screen.........................................................................................................19-3

Figure 19-3 Example 1: Configuring a Rule.................................................................................................19-4

Figure 19-4 Example 1: Destination Address for Traffic Originating from the Internet ..............................19-5

Figure 19-5 Example 1: Rule Summary Screen............................................................................................19-6

Figure 19-6 Send Alerts When Attacked......................................................................................................19-7

Figure 19-7 Configuring A POP Custom Port..............................................................................................19-8

Figure 19-8 Example 2: Local Network Rule 1 Configuration.....................................................................19-9

Figure 19-9 Example 2: Local Network Rule Summary.............................................................................19-10

Figure 19-10 Example: Internet to Local Network Rule Summary............................................................19-11

Figure 19-11 Custom Port for Syslog.........................................................................................................19-12

Figure 19-12 Syslog Rule Configuration....................................................................................................19-13

Figure 19-13 Example 3: Rule Summary...................................................................................................19-14

Figure 20-1 Categories Screen......................................................................................................................20-2

Figure 20-2 List Update Screen....................................................................................................................20-3

Figure 20-3 Exempt Zone Screen.................................................................................................................20-4

Figure 20-4 Customize Screen......................................................................................................................20-5

Figure 20-5 Keyword Screen ........................................................................................................................20-6

Figure 20-6 Logs Screen...............................................................................................................................20-7

xxii List of Figures

ZyWALL 10 Internet Security Gateway

List of Tables

Table 2-1 LED functions................................................................................................................................ 2-1

Table 2-2 Main Menu Commands .................................................................................................................. 2-5

Table 2-3 Main Menu Summary.....................................................................................................................2-7

Table 2-4 General Setup Menu Field............................................................................................................ 2-11

Table 2-5 Configure Dynamic DNS Menu Fields........................................................................................ 2-12

Table 2-6 WAN Setup Menu Fields.............................................................................................................. 2-13

Table 3-1 DHCP Ethernet Setup Menu Fields................................................................................................3-6

Table 3-2 LAN TCP/IP Setup Menu Fields....................................................................................................3-6

Table 3-3 IP Alias Setup Menu Fields............................................................................................................ 3-8

Table 3-4 Internet Access Setup Menu Fields................................................................................................ 3-9

Table 3-5 New Fields in Menu 4 (PPTP) screen.......................................................................................... 3-11

Table 3-6 New Fields in Menu 4 (PPPoE) screen........................................................................................3-12

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

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

Table 4-3 Fields in Menu 11.1 (PPTP Encapsulation).................................................................................... 4-5

Table 4-4 Remote Node Network Layer Options Menu Fields......................................................................4-6

Table 4-5 Remote Node Network Layer Options Menu Fields......................................................................4-8

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

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

Table 6-2 NAT Mapping Types...................................................................................................................... 6-3

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 — Configuring an Individual Rule.......................................................................6-12

Table 6-7 Services & Port numbers.............................................................................................................. 6-14

Table 7-1 Abbreviations Used in the Filter Rules Summary Menu................................................................ 7-6

List of Tables xxiii

ZyWALL 10 Internet Security Gateway

Table 7-2 Rule Abbreviations Used................................................................................................................7-6

Table 7-3 TCP/IP Filter Rule Menu Fields.....................................................................................................7-8

Table 7-4 Generic Filter Rule Menu Fields...................................................................................................7-12

Table 8-1 SNMP Configuration Menu Fields.................................................................................................8-2

Table 9-1 System Maintenance — Status Menu Fields...................................................................................9-2

Table 9-2 Fields in System Maintenance — Information ...............................................................................9-4

Table 9-3 System Maintenance Menu Syslog Parameters..............................................................................9-7

Table 9-4 System Maintenance Menu Diagnostic.........................................................................................9-12

Table 10-1 Filename Conventions ................................................................................................................10-2

Table 10-2 Third Party TFTP Clients — General commands.......................................................................10-8

Table 10-3 Third Party FTP Clients — General Fields...............................................................................10-12

Table 11-1 Budget Management ...................................................................................................................11-3

Table 11-2 Call History Fields ......................................................................................................................11-4

Table 11-3 Time and Date Setting Fields......................................................................................................11-6

Table 11-4 Menu 24.11 — Remote Management Control ............................................................................11-7

Table 13-1 Common IP Ports........................................................................................................................13-4

Table 14-1 ICMP Commands That Trigger Alerts........................................................................................14-3

Table 14-2 Legal NetBIOS Commands ........................................................................................................14-3

Table 14-3 Legal SMTP Commands.............................................................................................................14-3

Table 14-4 View Firewall Log ......................................................................................................................14-5

Table 15- 1 E-mail..........................................................................................................................................15-5

Table 15-2 SMTP Error Messages................................................................................................................15-6

Table 15- 3 Attack Alert...............................................................................................................................15-10

Table 16-1 Firewall Rules Summary — First Screen....................................................................................16-6

Table 16- 2 Pre defin ed Services.....................................................................................................................16-8

Table 16-3 Creating/Editing A Firewall Rule.............................................................................................16-11

Table 16-4 Adding/Editing Source and Destination Addresses..................................................................16-13

Table 16- 5 Timeout Menu...........................................................................................................................16-15

xxiv List of Tables

ZyWALL 10 Internet Security Gateway

Table 17-1 Custom Ports.............................................................................................................................. 17-2

Table 17-2 Creating/Editing A Custom Port................................................................................................ 17-4

Table 18-1 Log Screen ................................................................................................................................. 18-2

Table 21-1 Troubleshooting the Start-Up of your ZyWALL........................................................................ 21-1

Table 21- 2 Troubleshooting the LAN Interface ........................................................................................... 21-2

Table 21-3 Troubleshooting the WAN interface........................................................................................... 21-2

Table 21- 4 Troubleshooting Internet Access................................................................................................ 21-3

Table 21- 5 Troubleshooting the Firewall ..................................................................................................... 21-3

List of Tables xxv

ZyWALL 10 Internet Security Gateway

Preface

About Your Router

Congratulations on your purchase of the ZyWALL 10 Internet Security Gateway.

Don’t forget to register your ZyWALL (fast, easy online registration at www.zyxel.com) for free future product updates and information.

The ZyWALL 10 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. Your ZyWALL 10 is easy to install and configure. The ZyWALL Web Configurator (Web Configurator) is a web-based utility that allows you to access the ZyWALL’s management settings and configure the firewall. Most functions of the ZyWALL 10 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 10 via SMT but we recommend you

About This User's Manual

This manual is designed to guide you through the SMT configuration of your ZyWALL 10 for its various applications.

Structure of this Manual

This manual is structured as follows: Part I. Getting Started (Chapters 1 — 3) 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.

Part II. Advanced Applications (Chapters 4 — 6) describes the advanced applications of your

ZyWALL, such as Remote Node Setup, IP Static routes and NAT.

Part III. Advanced Management (Chapters 7 — 12) provides information on ZyWALL Filtering,

System Information and Diagnosis, Transferring Files, System Maintenance and Telnet.

Part IV. Firewall (Chapters 13 — 20) defines the term “firewall”, introduces the ZyWall firewall and

ZyWall web configurator, describes how to create custom rules and configure customized ports, explains logs and provides example firewall rules. Chapter 20 explains content filtering and how to use the ZyWALL to restrict web features such as ActiveX controls, Java applets and cookies, disable web proxies and block specific URLs.

Part V. Troubleshooting (Chapter 21) provides information about solving common problems as well as

some Appendices, a Glossary and an Index.

configure the firewall using the ZyWALL Web Configurator.

Preface xxvii

ZyWALL 10 Internet Security Gateway

Regardless of your particular application, it is important that you follow the steps outli ned in Chapters 1 and 2 to connect your ZyWALL to your LAN. You can then refer to the appropriate chapters of the manual, depending o n your applications.