Netopia R7200 manual Important notes

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C-6 User’s Reference Guide

If the WWW server on the Internet then tries to open a connection to the IP address of 200.1.1.40 with the appropriate exported service defined, the Netopia R7200 will look at the destination port and will find that it is destined for port 21 (FTP). The Netopia R7200 then looks at the internal user-defined exported services table and finds that any incoming IP traffic from the WAN port with a destination of port 21 (FTP) should be redirected to the IP address of 192.168.5.3 on the local LAN interface, which in this case is Workstation B.

Once the appropriate exported services are defined, there can be seamless communication between a host on the Internet and a host on the Netopia R7200’s local LAN interface.

Important notes

Even with the advantages of NAT, there are several things you should note carefully:

■There is no formally agreed-upon method among router vendors for handling an all-zeros IPCP request. The majority of router vendors use the all-zeros IPCP request to determine when a dial-in host wants to be assigned an IP address. Some vendors however attempt to negotiate and establish routing with an all-zeros IP address. The Netopia R7200 will not allow routing to be established with an all-zeros IP address and the call will be dropped with an error logged in the Device Event History.

■When using NAT it is most likely that the Netopia R7200 will be receiving an IP address from a pool of dynamic IP addresses at the ISP. This means that the Netopia R7200's IP presence on the Internet will change with each connection. This can potentially cause problems with devices on the Internet attempting to access services like WWW and FTP servers or AURP partners on the Netopia R7200’s local LAN interface. In this case, if a dynamic IP address is assigned to the WAN interface of the Netopia R7200 each time, the administrator of the Netopia R7200 will have to notify clients who want to access services on the Netopia R7200’s LAN interface of the new IP address after each connection.

■With NAT enabled, there cannot be two or more of the same types of service accessible from the Internet on the LAN interface of the Netopia R7200. For example, there cannot be multiple FTP servers (Port 23) on the Netopia R7200's LAN interface that can be accessible by workstations on the Internet. This is because there is no way within the Netopia R7200 and IP to distinguish between multiple servers using the same port, in this case port 23.

■Fictional IP addresses may be assigned on the Netopia R7200’s LAN interface. It is strongly recommended that for the Netopia R7200’s LAN interface, an IP address from the Class C address range of 192.168.X.X be used. This is because this range is defined by the IANA as an address space that will never be routed through the Internet and is to be used by private Intranets not attached to the Internet.

If the address range of 192.168.X.X is not used and another range of addresses such as 100.1.1.X is used instead, this address space can potentially overlap an address space that is owned by a user attached to the Internet. Thus if a user on the Netopia R7200’s LAN interface has an IP address of

100.1.1.2while the Netopia R7200’s LAN interface is 100.1.1.2 and the local host wants to access a host on the Internet with the address of 100.1.1.8, the Netopia R7200 has no way of knowing that the

200.1.1.8address is actually on the Internet and not on its local LAN interface, since the local LAN interface is assigned the IP address range of 200.1.1.1 to 200.1.1.14.

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Contents Netopia R7200 Sdsl Router Part Number Contents Part II Advanced Configuration Contents Aurp Snmp Xmodem Part III Appendixes User’s Reference Guide Part I Getting Started User’s Reference Guide Chapter Introduction Features and capabilitiesOverview How to use this guide Chapter Setting Up Internet Services Finding an Internet service providerPricing and support Setting up a Netopia R7200 account Obtaining an IP addressUnique requirements Endorsements Deciding on an ISP accountWith Network Address Translation Obtaining information from the ISPLocal LAN IP address information to obtain Without Network Address TranslationUser’s Reference Guide Chapter Making the Physical Connections Find a locationIdentify the connectors and attach the cables What you needNetopia R7200 Sdsl Router back panel ports Your router onNetopia R7200 Sdsl Router status lights Netopia R7200 LED front panelChapter Connecting to Your Local Area Network Readying computers on your local networkUser’s Reference Guide Connecting to an Ethernet network 10Base-T Adding an external modem Connecting to a LocalTalk network Chapter Setting up your Router with the SmartStart Wizard Before running SmartStart Setting up your Router with the SmartStart Wizard SmartStart Wizard configuration screensAdvanced setup Easy optionAdvanced option Configuration screen on Dynamic configuration recommended Configuration tabStatic configuration optional Add. Repeat this process for the secondary DNS Configuring TCP/IP on Macintosh computers TCP/IPTCP/IP or MacTCP Dynamic configuration using MacIP optional Setting up your Router with the SmartStart Wizard User’s Reference Guide Chapter Console-Based Management Connecting through a Telnet session Connecting a console cable to your router Configuring Telnet softwareNavigating through the console screens PC ANSI-BBSEasy Setup console screens Chapter Easy SetupAccessing the Easy Setup console screens See Appendix A, Troubleshooting, for more suggestions Quick Easy Setup connection path Sdsl Line Configuration Main Menu appearsEasy Setup Profile Previous Screen Next ScreenIP Easy Setup Easy Setup Security Configuration Previous Screen To Main Menu Part II Advanced Configuration User’s Reference Guide Chapter WAN and System Configuration WAN configurationATM VPI ATM VCI Creating a new Connection Profile IPX Profile Parameters Remote IPX Network Datalink PPP/MP Options Data Compression Default profile Main Menu Default Profile screen appears IP parameters default profile screen IPX parameters default profile screen System configuration screensNavigating through the system configuration screens System configuration features IP address serving Network protocols setupFilter sets firewalls Date and timeConsole configuration Security Upgrade feature setSnmp Simple Network Management Protocol LoggingInstalling the Syslog client User’s Reference Guide Chapter Line Backup Backup Configuration screen appears Backup Configuration screen AtdtIP Setup screen Using Scheduled Connections with Backup Connection ProfilesScheduled Connections screen appears Management/Statistics Force Recovery Event Logs QuickViewSnmp Support User’s Reference Guide Chapter IP Setup and Network Address Translation Network Address Translation featuresHOW NAT Works Using Network Address Translation Previous ScreenV2 multicast Numbered Associating port numbers with nodes Sdsl WAN1Advanced IP/IPX router configuration options Data Link Options IP Setup and Network Address Translation Network Address Translation guidelines IP setup User’s Reference Guide Select Add Export. The Add Exported Service screen appears Select Service. a pop-up menu of services and ports appears IP subnets User’s Reference Guide Static routes Static Routes screen will appear Viewing static routesAdding a static route Modifying a static route Rules of static route installationDeleting a static route Main Menu System Configuration IP Address Serving 176.163.222.10 Dhcp NetBios Options Serve Bootp Clients IP Address Pools IP Setup and Network Address Translation Dhcp NetBIOS Options NetBios Type MacIP KIP forwarding setup You have finished your IP setup User’s Reference Guide IPX definitions Chapter IPX SetupIPX features Internetwork Packet Exchange IPXSocket Service Advertising Protocol SAPIPX address Routing Information Protocol RIPIPX setup screen NetBIOSIPX spoofing Default Gateway Address IPX routing tables User’s Reference Guide AppleTalk networks Chapter AppleTalk SetupAppleTalk protocol AT Routing Table MacIP Routers and seedingInstalling AppleTalk Upgrade Feature Set EtherTalk setup Configuring AppleTalkLocalTalk setup Viewing Aurp partners Aurp setupAurp Free Trade Zone Adding an Aurp partner Modifying an Aurp partnerReceiving Aurp connections Deleting an Aurp partnerConfiguring Aurp Options Aurp Options Tickle Interval Hhmmss User’s Reference Guide Chapter Monitoring Tools Quick View status overviewGeneral status Current status Status lightsStatistics & Logs General StatisticsPhysical Interface Event historiesNetwork Interface WAN Event History Routing tables Device Event HistoryIP routing table IPX Sap Bindery table IPX routing tableAppleTalk routing table Served IP Addresses IP Address Lease Management screen appears System Information SnmpSnmp Setup screen Community stringsSnmp traps Modifying IP trap receivers Setting the IP trap receiversViewing IP trap receivers Deleting IP trap receiversWeb-based management pages Event History pages WAN Event History Device Event History User’s Reference Guide Suggested security measures Chapter SecurityUser accounts Protecting the Security Options screen Protecting the configuration screensDial-in console access About filters and filter sets Enable SmartStart/SmartView/Web serverTelnet access What’s a filter and what’s a filter set?How filter sets work Filter priorityHow individual filters work Parts of a filter filtering rulePort numbers Port number comparisons Other filter attributesPutting the parts together UDPFiltering example #1 Filtering example #2Design guidelines Disadvantages of filtersAn approach to using filters Working with IP filters and filter setsAdding a filter set Naming a new filter setInput and output filters-source and destination Adding filters to a filter setADD this Filter NOW Cancel Modifying filters Viewing filter setsViewing filters Deleting filtersDeleting a filter set Modifying filter setsSample IP filter set TCP Icmp UDP Possible modifications User’s Reference Guide IPX filters Viewing and modifying packet filters IPX packet filtersAdding a packet filter Viewing and modifying packet filter sets IPX packet filter setsDeleting a packet filter Adding a packet filter setNo Match Deleting a packet filter set IPX SAP filtersViewing and modifying SAP filters Adding a SAP filter Deleting a SAP filterViewing and modifying SAP filter sets IPX SAP filter setsAdding a SAP filter set Deleting a SAP filter set Basic IP packet components Firewall tutorial General firewall termsBasic protocol types Example TCP/UDP Ports Firewall design rulesFirewall Logic Binary representation Logical and functionEstablished connections Implied rulesExample IP filter set screen Filter basics Example networkExample filters ExampleExample Example Chapter Utilities and Diagnostics Ping Receive return Ping packet Trace Route Stop PingTelnet client Factory defaults Disconnect Telnet console sessionTransferring configuration and firmware files with Tftp Updating firmwareDownloading configuration files Uploading configuration files Transferring configuration and firmware files with XmodemIdle Do you want to send a saved configuration to your Netopia? Restarting the system Part III Appendixes User’s Reference Guide Appendix a Troubleshooting Configuration problemsConsole connection problems Network problemsHow to reset the router to factory defaults Power outagesBefore contacting Netopia How to reach usTechnical support Environment profileOnline product information FAX-BackUser’s Reference Guide Appendix B Understanding IP Addressing What is IP?About IP addressing Subnets and subnet masks Example Using subnets on a Class C IP internet Subnet masksNetwork configuration ISP NetworkDistributing IP addresses Example Working with a Class C subnetBackground Technical note on subnet masking Configuration Netopia R7200 Dhcp server characteristicsDhcp address serving MacIP serving Using address servingManually distributing IP addresses Serve dynamic WAN clientsTips and rules for distributing IP addresses Understanding IP Addressing B-9Dhcp example Nested IP subnets Internet0.0 C.1 WAN 3719 Broadcasts Packet header typesUser’s Reference Guide Network configuration Appendix C Understanding Netopia NAT BehaviorBackground User’s Reference Guide Understanding Netopia NAT Behavior C-3 Netopia Router WWW Server ISP Router LAN Exported services Understanding Netopia NAT Behavior C-5Important notes Understanding Netopia NAT Behavior C-7 Summary Appendix D Binary Conversion Table Decimal Binary Appendix E Further Reading User’s Reference Guide Further Reading E-3 User’s Reference Guide Appendix F Technical Specifications and Safety Information Pinouts for Auxiliary port modem cableDescription Power requirementsEnvironment Software and protocols North America Agency approvalsRegulatory notices InternationalImportant safety instructions Declaration for Canadian usersTelecommunication installation cautions BatteryAppendix G About Sdsl User’s Reference Guide Glossary User’s Reference Guide Glossary User’s Reference Guide Remapping See network number remapping User’s Reference Guide Glossary User’s Reference Guide Index NumericsIndex-2 Index-3 Index-4 Index-5 Index-6 Limited Warranty and Limitation of Remedies User’s Reference Guide
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