Configuring a Server behind NAT | ZyXEL Communications P-312

P312 Broadband Security Gateway

Figure 6-10 Multiple Servers Behind NAT

6.3.2 Configuring a Server behind NAT

Follow the steps below to configure a server behind NAT:

Step 1. Enter 15 in the main menu to go to Menu 15 – NAT Setup. Step 2. Enter 2 to go to Menu 15.2 - NAT Server Setup.

Step 3. Enter the service port number in the Port # field and the inside IP address of the server in the IP Address field.

Step 4. Press [ENTER] at the “Press ENTER to confirm …” prompt to save your configuration after you define all the servers or press ESC at any time to cancel.

Note: If you’re using Ethernet Encapsulation with either RR-Manager or RR-Toshiba

Service Type, then the SMT does not allow you to change the port 1025 entry.

The most often used port numbers are shown in the following table. Please refer to RFC 1700 for further information about port numbers. Please also refer to our included disk for more examples and details on NAT.

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NAT

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ZyXEL Communications P-312 manual Configuring a Server behind NAT, Multiple Servers Behind NAT

Contents

Prestige Disclaimer CopyrightTrademarks Federal Communications Commission FCC Interference Statement Information for Canadian Users Version Declaration of Conformity P312 Broadband Security Gateway CE Doc ZyXEL Limited Warranty Information in Menu 24.2.1 -System Information Customer Support Table of Contents LAN Port Filter Setup Chapter Advanced Management 12-1 13-1 Firewall and Content Filters 17-1 Pptp 21-1 Menu 11.1 Remote Node Profile for Ethernet Encapsulation List of Figures List Of Figures Xvii Xviii List Of Figures Xix Menu 21 Filter and Firewall Setup 14-1 List Of Figures Xxi Page List Of Tables Xxiv List of Tables Xxv Page About Your Router PrefaceStructure of this Manual Syntax Conventions Related Documentation Part Page Getting to Know Your Prestige Features of The PrestigePrestige 312 Broadband Security Gateway Time and Date Setting Dhcp Dynamic Host Configuration ProtocolDynamic DNS Support IP Multicast Upgrade Prestige Firmware via LAN Broadband Internet Access via Cable or xDSL ModemApplications for Prestige Logging and Tracing Secure Internet Access via DSL Front Panel LEDs and Back Panel Ports Hardware Installation & Initial SetupFront Panel LEDs LED functions WAN Prestige 312 Rear Panel and Connections Additional Installation Requirements Power Up Your Prestige HousingEntering Password Initial Screen Navigating the SMT Interface Main Menu CommandsOperation Keystrokes Description Enter System Management Terminal Interface Summary Main MenuPrestige 312 Main Menu Main Menu Summary Resetting the Prestige Changing the System Password Dynamic DNS General SetupDyndns Wildcard General Setup Menu Field Configuring Dynamic DNSConfigure Menu 1.1 Configure Dynamic DNS discussed next Field Description Example Configure Dynamic DNS Menu Fields WAN SetupYes Me.ddns.org WAN Setup Menu Fields LAN Setup 10 Menu 3 LAN Setup LAN Port Filter Setup Factory LAN Defaults Internet AccessTCP/IP and Dhcp for LAN IP Address and Subnet Mask Private IP Addresses RIP Setup IP Pool Setup Dhcp ConfigurationIP Multicast DNS Server Address IP Alias TCP/IP and Dhcp Ethernet SetupPhysical Network Partitioned Logical Networks Menu 3 LAN Setup 10/100 Mbps Ethernet LAN TCP/IP Setup Menu Fields LAN Dhcp Setup Menu Fields Menu 3.2.1 IP Alias Setup IP Alias SetupIP Alias Setup Menu Fields Ethernet Encapsulation Internet Access SetupOnly/Out Only RIP-1 Pptp Encapsulation Internet Access Setup Menu Fields PPPoE Encapsulation Configuring the Pptp ClientNew Fields in Menu 4 Pptp screen Prestige automatically disconnects from the Pptp server Internet Access Setup PPPoE New Fields in Menu 4 PPPoE screen Basic Setup Complete Advanced Applications Remote Node Profile Remote Node Setup Fields in Menu Nailed-Up Connection Fields in Menu 11.1 PPPoE Encapsulation Specific Fields in Menu 11.1 Pptp Encapsulation Remote Node Network Layer Options Menu Fields Editing TCP/IP Options with Ethernet Encapsulation Private Editing TCP/IP Options with Pptp EncapsulationVersion 2B/RIP-2M and None Multicast Remote Node Network Layer Options Editing TCP/IP Options with PPPoE Encapsulation Remote Node FilterYes/No None/In Only/Out Only and None Remote Node Filter Ethernet Encapsulation Example of Static Routing Topology IP Static Route Setup Menu 12 IP Static Route Setup IP Static Route Setup Field Description IP Static Route Menu FieldsPage Introduction Network Address Translation NATNAT Definitions What NAT Does NAT Mapping Types How NAT works NAT Mapping Types SUA Single User Account Versus NATType IP Mapping SMT abbreviation NAT Application SMT MenusApplying NAT in the SMT Menus Applying NAT for Internet Access Field Options Description Network Full Feature Configuring NATAddress Mapping Sets and NAT Server Sets Applying NAT in Menus 4 Menu 15.1 Address Mapping Sets Server Field Description Options/Example Menu Ordering Your Rules Editing an Individual Rule in a Set Menu 15.1.1.1 configuring an individual rule Multiple Servers behind NAT NAT Server Sets 10 Multiple Servers Behind NAT Configuring a Server behind NAT Services Port Number Internet Access OnlyExamples NAT Example 13 Internet Access & NAT Example Example 3 General Case Example 2 Internet Access with an Inside Server 16 NAT Example 17 Example 3 Menu 19 Example 3 Final Menu 21 NAT Example Example 4 -NAT Unfriendly Application Programs 22 Example 4- Menu 15.1.1.1 Address Mapping Rule Advanced Management Page About Filtering Filter Configuration Filter Structure of the Prestige Rule Forward Drop Filter Rule Process Menu 21 Filter and Firewall Setup Configuring a Filter Set NetBIOSWAN Filter Rules Summary Abbreviations Used in the Filter Rules Summary Menu Filter Rules Summary MenuAbbreviations Description Display Action Not Matched will be N/A Refers to Action Matched 3 TCP/IP Filter Rule Configuring a Filter RuleAbbreviations Used If Filter Type Is IP Abbreviations Used If Filter Type Is GEN TCP/IP Filter Rule Menu Fields Menu 21.1.1.1 TCP/IP Filter Rule Equal/Not Equal None/Less/GreaterYes / No Action Matched Following diagram illustrates the logic flow of an IP filter 10 Executing an IP Filter 11 Menu 21.4.1.1 Generic Filter Rule Generic Filter Rule Generic Filter Rule Menu Fields 12 Telnet Filter Example Example Filter 13 Example Filter Menu 14 Example Filter Rules Summary Menu Filter Types and NAT Firewall Applying a Filter and Factory DefaultsLAN traffic 16 Filtering LAN Traffic Remote Node Filters Configuring Snmp Snmp ConfigurationAbout Snmp Field Description Default Snmp Configuration Menu Fields System Information & Diagnosis Menu 24 System Maintenance System Status Menu 24.1 System Maintenance Status PPPoE Encapsulation System Maintenance Status Menu FieldsLAN Dhcp System Information System Information and Console Port Speed Log and Trace Fields in System MaintenanceConsole Port Speed Unix Syslog Viewing Error Log Parameter Description System Maintenance Menu Syslog ParametersCDR CDR PPP log Call-Triggering Packet Diagnostic WAN Dhcp 10 Menu 24.4 System Maintenance Diagnostic Internet Setup in Menu 4 Internet Access System Maintenance Menu DiagnosticNumber Field Description Filename conventions Transferring Files Command Backup ConfigurationFirmware Development Filename Conventions Upload Firmware Restore ConfigurationUploading the Router Firmware Menu 24.7.1 System Maintenance Upload Router Firmware Uploading Router Configuration File Tftp File Transfer Third Party Tftp Clients -General fields Example Tftp Command Telnet into Menu FTP File Transfer Telnet into Menu 24.7.2 System Maintenance Using the FTP command from the DOS Prompt Third Party FTP Clients -General fields Page Command Interpreter Mode System Maintenance & InformationValid Commands Budget Management Call Control SupportCall Control Call History Call History How often does the Prestige update the time? Time and Date SettingCall History Fields System Maintenance & Information 11-5 Menu 24.11 Remote Management Control Remote Management Setup Option to Enter Debug Mode Boot Commands Boot Module Commands About Telnet Configuration Telnet Configuration and CapabilitiesSingle Administrator Telnet Under NAT Telnet Under the Firewall System Timeout Firewall and Content Filters Types of Firewalls What is a FirewallPacket Filtering Firewalls Application-level Firewalls Stateful Inspection firewalls Introduction to ZyXEL’s Firewall Basics Denial of Service Common IP Ports Types of DoS attacks SYN Flood Smurf Attack Stateful Inspection Stateful Inspection Stateful Inspection Process TCP Security Stateful Inspection & the Prestige 13.4.4 UDP/ICMP Security Guidelines For Enhancing Security With Your FirewallUpper Layer Protocols Security In General What Is a Firewall? 13-11 Page SMT Main Menu Introducing the Prestige Firewall Attack Types View Firewall LogLand IP Spoofing Illegal Commands NetBIOS and Smtp Icmp Commands That Trigger AlertsLegal NetBIOS Commands Legal Smtp Commands Teardrop Traceroute Big Picture Filtering, Firewall and NAT Packet Filtering Packet Filtering Vs Firewall When To Use The Firewall When To Use FilteringFirewall Page Web Configurator Login and Welcome Screens Introducing the Prestige Web Configurator Enabling the Firewall Prestige Web Configurator Welcome Screen What are Alerts? Mail Mail Screen What are Logs? Mail Smtp Error Messages Smtp Error MessagesExample E-Mail Log Mail Log Attack Alert Half-Open Sessions Threshold ValuesTCP Maximum Incomplete And Blocking Time Attack Alert Existing half-open sessions Field Description Default Values Do not set Maximum Incomplete High to When TCP Maximum Incomplete isPage Creating Custom Rules Rule ChecklistRules Overview Rule Logic Overview Security Ramifications Key Fields For Configuring Rules LAN to WAN Rules Connection DirectionWAN to LAN Rules WAN to LAN Traffic Services Supported Service Description Services Supported Firewall Rules Summary First Screen Rule Summary Match Block Field Description Option Creating/Editing Firewall Rules Creating/Editing a Firewall Rule Source & Destination Addresses Single Address Adding/Editing Source & Destination AddressesRange Address Subnet Address Factors Influencing Choices for Timeout Values Timeout Timeout Screen Field Description Default Value Timeout MenuHour Custom Ports Custom Ports Creating/Editing a Custom Port Creating/Editing a Custom Port Range Single Log Screen LogsLog Screen Command, traceroute, teardrop, or syn Vulnerability, NetBIOS, smtp illegalJan 1 Src IP, dest port, src port and protocol Logs 18-3 Page Example Firewall Rules Activate The Firewall Example 1 E-Mail Screen Example 1 Configuring a Rule Example Firewall Rules 19-5 Example 1 Rule Summary Screen Example 2 Small Office With Mail, FTP and Web Servers Send Alerts When Attacked Configuring a POP Custom Port Example 2 Local Network Rule 1 Configuration Example 2 Local Network Rule Summary 10 Example 2 Internet to Local Network Rule Summary 11 Custom Port for Syslog 12 Syslog Rule Configuration 13 Example 3 Rule Summary Restrict Web Features Content FilteringActiveX Java Blocking URLs Content Filtering Using the Web ConfiguratorCookies Web Proxy Field Description Restrict Web Features Content Filtering FieldsBlock Web URLs Troubleshooting, Appendices, Glossary and Index Page Problems Starting Up the Prestige TroubleshootingTroubleshooting the Start-Up of your Prestige Problem Corrective Action Problems with the WAN interface Problems with the LAN InterfaceTroubleshooting the LAN Interface Troubleshooting the WAN interface Problems with the Firewall Problems with Internet AccessTroubleshooting Internet Access Page Appendix a PPPoE Diagram 1 Single-PC per Modem Hardware ConfigurationPPPoE in Action Benefits of PPPoE How PPPoE Works Diagram 2 Prestige as a PPPoE ClientPrestige as a PPPoE Client Appendix B What is PPTP?Pptp and the Prestige Pptp Protocol Overview Control & PPP connections Mtbf Appendix C Hardware SpecificationsIRD + OTD + Appendix D Important Safety Instructions Function CLI Syntax Appendix E Firewall CLI Commands Sets Function CLI Syntax Description P312 Broadband Security Gateway Delete AC Power Adapter Specifications Appendix F Power Adapter Specs P312 Broadband Security Gateway ARP Glossary of TermsCDR Chap CSU/DSU DCE Dslam Dram DSLDTE EMI FCC FAQFTP Hdlc IRC ISP Ipcp PPP IPXMAC Ndis NATNIC PAP Pots PPP POPPstn RFC PVCRIP SAP STP SpamSUA TCP Tftp VPN Page Ddns Index Encapsulation 2-11, 2-12, 3-4 13-6 15-1 ZyNOS