Firewall tutorial General Firewall Terms | Netopia R3100 specs

15-30 User’s Reference Guide

Firewall tutorial

General Firewall Terms

Firewall: a component or set of components that restrict access between a protected network and the Internet, or between two networks.

Host: A workstation on the Network.

Packet: Unit of communication on the Internet.

Packet Filter: Packet ﬁlters allow or deny packets based on source or destination IP addresses, TCP or UDP ports, or the TCP ACK bit.

Port: A number that deﬁnes a particular type of service.

Filter Rule: A ﬁlter set is comprised of individual ﬁlter rules.

Filter Set: A grouping of individual ﬁlter rules.

Basic IP Packet Components

All IP packets contain the same basic “header” information, as follows:

Source IP Address	163.176.132.18

Destination IP Address	163.176.4.27

Source Port	2541

Destination Port	80

Protocol	TCP

ACK Bit	Yes

DATA	User Data

This header information is what the packet ﬁlter uses to make ﬁltering decisions. It is important to note that a packet ﬁlter does not look into the IP datastream (the User Data from above) to make ﬁltering decisions.

Basic Protocol Types

TCP: Transmission Control Protocol. TCP provides reliable packet delivery and has a retransmission mechanism (so packets are not lost). RFC 793 is the speciﬁcation for TCP.

UDP: User Datagram Protocol. Unlike TCP, UDP does not guarantee reliable, sequenced packet delivery. If data does not reach its destination, UDP does not re transmit the data. RFC 768 is the speciﬁcation for UDP.

And there are many more ports deﬁned in the Assigned Addresses RFC.

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Netopia R3100 manual Firewall tutorial General Firewall Terms, Basic IP Packet Components, Basic Protocol Types

Contents

Netopia R3100 Isdn Routers Part Number Contents Ii User’s Reference Guide Part II Advanced Configuration Iv User’s Reference Guide Aurp Vi User’s Reference Guide Part III Appendixes Viii User’s Reference Guide Contents User’s Reference Guide Conﬁguration options for your Netopia R3100 Isdn Router Small Ofﬁce connection to the Internet Small Ofﬁce connection to the Internet Direct Connection to a Corporate Ofﬁce Telecommuter Conﬁgured to accept incoming dial-up connections Conﬁgured for Idsl Part I Getting Started User’s Reference Guide Features and capabilities Chapter IntroductionOverview Introduction How to use this guide Chapter Making the Physical Connections Find a locationWhat you need Making the Physical Connections Identify the connectors and attach the cables Netopia R3100 Isdn Router Back Panel Ports Cable to your router on Services on Netopia R3100 Isdn Router Status Lights Netopia R3100 LED front panel Chapter Setting up your Router with the SmartStart Wizard Setting up your Router with the SmartStart Wizard Before running SmartStart Setting up your Router with the SmartStart Wizard SmartStart Wizard conﬁguration screens Easy or Advanced setup Easy option Setting up your Router with the SmartStart Wizard User’s Reference Guide Setting up your Router with the SmartStart Wizard User’s Reference Guide Advanced option Connection Proﬁle screen on Dynamic conﬁguration recommended Conﬁguration tab Static conﬁguration optional Add. Repeat this process for the secondary DNS Conﬁguring TCP/IP on Macintosh computers TCP/IP TCP/IP or MacTCP Dynamic conﬁguration using MacIP optional Setting up your Router with the SmartStart Wizard User’s Reference Guide Chapter Connecting Your Local Area Network Connecting Your Local Area Network Readying computers on your local network Connecting to an Ethernet network 10Base-T 10BASE-T Remote console Connecting to a LocalTalk network Wiring guidelines for PhoneNET cabling User’s Reference Guide SmartView overview Chapter SmartViewSmartView Navigating SmartView General Machine information Connection Proﬁles Event history pages Device Event History WAN Event History Standard Html web-based monitoring pages User’s Reference Guide About Console-based Management Chapter Console-based ManagementConsole-based Management Connecting through a Telnet session Connecting a local terminal console cable to your router Conﬁguring Telnet software PC ANSI-BBS Navigating through the console screens User’s Reference Guide Chapter Easy Setup Easy Setup console screensHow to access the Easy Setup console screens Easy Setup See Appendix A, Troubleshooting, for more suggestions Beginning Easy Setup Isdn Easy Setup PPP Cancel Idsl Easy Setup Easy Setup Proﬁle Previous Screen User’s Reference Guide IP Easy Setup Previous Screen Next Screen Easy Setup Security Conﬁguring Frame Relay Easy Setup Frame Relay screens Isdn Setup Isdn Line Configuration WAN Conﬁguration Frame Relay screens Frame Relay conﬁguration Easy Setup Frame Relay Dlci conﬁguration Displaying a Frame Relay Dlci conﬁguration table Changing a Frame Relay Dlci conﬁguration ADD Dlci NOW Cancel Adding a Frame Relay Dlci conﬁguration Deleting a Frame Relay Dlci conﬁguration Part II Advanced Configuration User’s Reference Guide Creating a new Connection Proﬁle Chapter WAN and System ConfigurationWAN and System Conﬁguration Add Connection Proﬁle screen appears IPX Profile Parameters Remote IPX Network BAP Telco Options Initiate Data Service 64 kb/sec Dial Default Proﬁle How the default proﬁle works Customizing the Default Proﬁle Configuration Default Profile IP parameters default proﬁle screen WAN and System Conﬁguration IPX parameters default proﬁle screen Auxiliary Port Conﬁguration System Conﬁguration screens System Conﬁguration features PAP Network Protocols Setup Filter Sets FirewallsIP Address Serving Date and Time MM/DD/YY Upgrade Feature Set Console ConﬁgurationSnmp Simple Network Management Protocol Security Telephone setup Logging Nov Using SmartPhone for Telephone Services Chapter Using SmartPhone for Telephone ServicesSpecifying telephone connections Inbound Directory Number Using SmartPhone for Telephone Services Deﬁning priority ringing Preview Ring Advanced calling features Line provisioning Conﬁguring supplementary services Cost control feature -- call accounting Chapter Call Accounting and Default Answer ProfileCall Accounting and Default Answer Proﬁle Viewing call accounting statistics Call Accounting Statistics screen appears Scheduled connections Viewing scheduled connections Adding a scheduled connection Set Weekly Schedule Set Once-Only Schedule Default Answer Proﬁle How the Default Answer Proﬁle worksModifying a scheduled connection Deleting a scheduled connection Customizing the default proﬁle Call Accounting and Default Answer Proﬁle Call acceptance scenarios Network Address Translation features Chapter IP Setup and Network Address TranslationIP Setup and Network Address Translation HOW NAT Works Using Network Address Translation ISP Associating port numbers to nodes Using multiple Connection ProﬁlesNetwork Address Translation guidelines IP setup IP Setup and Network Address Translation Select Add Export. The Add Exported Service screen appears IP Setup IP subnets IP Setup and Network Address Translation Static routes Viewing static routes Adding a static route Modifying a static route Rules of static route installationDeleting a static route Main System IP Address Menu Configuration Serving 163.176.56.90 Dhcp NetBIOS Options MacIP Kip Forwarding Options You have ﬁnished your IP Setup Chapter IPX Setup IPX FeaturesIPX Setup IPX Deﬁnitions Service Advertising Protocol SAP IPX addressSocket Routing Information Protocol RIP IPX setup NetBIOSIPX Spooﬁng Default Gateway Address IPX routing tables User’s Reference Guide Installing AppleTalk Chapter AppleTalk SetupAppleTalk Setup AppleTalk networks AppleTalk protocol AppleTalk Setup MacIP Aurp Routers and seeding Conﬁguring AppleTalk EtherTalk Setup LocalTalk Setup Viewing Aurp partners Aurp setupAurp Free Trade Zone Adding an Aurp partner Modifying an Aurp partner Receiving Aurp connections Deleting an Aurp partnerConﬁguring Aurp Options User’s Reference Guide Quick View status overview Chapter Monitoring ToolsMonitoring Tools General status Current status Status lights Statistics & Logs General Statistics Physical Interface Event historiesNetwork Interface WAN Event History Request from our DN Routing tables Device Event History IP routing table IPX Sap Bindery table IPX routing tableAppleTalk routing table Served IP Addresses IP Address Lease Management screen appears System Information Snmp Snmp Setup screen Community strings Snmp traps Setting the IP trap receivers Viewing IP trap receiversModifying IP trap receivers Deleting IP trap receivers User’s Reference Guide Suggested security measures Chapter SecuritySecurity Protecting the Security Options screen User accountsProtecting the conﬁguration screens Dial-in Console Access Enable SmartStart/SmartView/Web Server Telnet accessAbout ﬁlters and ﬁlter sets What’s a ﬁlter and what’s a ﬁlter set? How ﬁlter sets work Filter priority Packet First filter Match? Yes How individual ﬁlters work ﬁlter’s actionsﬁltering rule Parts of a ﬁlter Port numbers Port number comparisons Other ﬁlter attributes Putting the parts together UDP Filtering example #1 Design guidelines Filtering example #2 Working with IP ﬁlters and ﬁlter sets An approach to using ﬁltersDisadvantages of ﬁlters Adding a ﬁlter set Naming a new ﬁlter set Input and output ﬁlters-source and destination Netopia R-series Router Adding ﬁlters to a ﬁlter set ADD this Filter NOW Cancel Viewing ﬁlter sets Viewing ﬁltersModifying ﬁlters Deleting ﬁlters Deleting a ﬁlter set Modifying ﬁlter setsSample IP ﬁlter set TCP Icmp UDP Possible modiﬁcations Security IPX ﬁlters Viewing and modifying packet ﬁlters IPX packet ﬁltersAdding a packet ﬁlter IPX packet ﬁlter sets Deleting a packet ﬁlterViewing and modifying packet ﬁlter sets Adding a packet ﬁlter set ADD Filter SET NOW Cancel Deleting a packet ﬁlter set IPX SAP ﬁltersViewing and modifying SAP ﬁlters Adding a SAP ﬁlter IPX SAP ﬁlter sets Deleting a SAP ﬁlterViewing and modifying SAP ﬁlter sets Adding 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 Logical ANDing Binary RepresentationImplied Rules Established Connections Filter BasicsExample IP Filter Set Screen Example Network Example FiltersExample Example Example Token Security Authentication Using the SecurID token cardKey Security Authentication Features of the Netopia R3100 Securing network environments Security authentication components Conﬁguring for security authentication Connecting using security authentication Establishing a dial-on-demand DOD connection call Current Connection Status Establishing a manual connection call User’s Reference Guide Chapter Utilities and Diagnostics Utilities and Diagnostics Ping Start Ping Utilities and Diagnostics Telnet client Stop Ping Trace Route Telnet client screen appears Secure Authentication Monitor Disconnect Telnet Console Session Factory defaultsTransferring conﬁguration and ﬁrmware ﬁles with Tftp Updating ﬁrmware Downloading conﬁguration ﬁles Uploading conﬁguration ﬁles Transferring conﬁguration and ﬁrmware ﬁles with Xmodem Do you want to send a saved configuration to your Netopia? Restarting the system Isdn Switch Loopback Test User’s Reference Guide If the loopback test fails Part III Appendixes User’s Reference Guide Conﬁguration problems Appendix a TroubleshootingTroubleshooting A-1 Console connection problems SmartStart TroubleshootingNetwork problems Power outages How to get supportTechnical support Before contacting Netopia Online product information FAX-Back Appendix B Setting Up Telco Services Finding an Isdn service providerObtaining an Isdn line Choosing an Isdn line Physical Isdn line Setup tipsIsdn Ordering Codes Switch protocol type Outside North America onlyDirectory and Spid numbers U models only Circuit ID number U models only Testing the Isdn line Long-distance Isdn calls North American models only Completing the Isdn worksheet Isdn Telco Worksheet for North America Isdn Telco Worksheet for Outside North America User’s Reference Guide Appendix C North American Telco Provisioning for Isdn North American Telco Provisioning for Isdn User’s Reference Guide Appendix D Setting Up Internet Services Finding an Internet service providerSetting Up Internet Services D-1 Unique requirements Setting up a Netopia R3100 account Pricing and supportISP’s Point of presence Endorsements Deciding on an ISP account Obtaining information from the ISP Local LAN IP address information to obtainWith Network Address Translation Remote WAN IP address information to obtain Remote WAN IP address information to obtain What is IP? Appendix E Understanding IP AddressingAbout IP addressing Understanding IP Addressing E-1 Subnets and subnet masks Understanding IP Addressing E-3 Example Using subnets on a Class C IP internetSubnet masks Network conﬁguration ISP Network Example Working with a Class C subnet Distributing IP addressesUnderstanding IP Addressing E-5 Background Technical note on subnet masking Netopia R3100 Dhcp Server Characteristics ConﬁgurationUnderstanding IP Addressing E-7 Dhcp Address Serving Using address serving Manually distributing IP addressesTips and rules for distributing IP addresses MacIP Serving Understanding IP Addressing E-9 Dhcp example Nested IP subnets Internet Understanding IP Addressing E-11 Broadcasts Packet header types Appendix F Understanding Netopia NAT Behavior Network ConﬁgurationBackground Understanding Netopia NAT Behavior F-1 User’s Reference Guide Router Netopia Understanding Netopia NAT Behavior F-3 Router Netopia Exported services Understanding Netopia NAT Behavior F-5 Important notes Understanding Netopia NAT Behavior F-7 Summary Virtual Circuits Appendix G Understanding Frame RelayUnderstanding Frame Relay G-1 Committed Burst Size Bc Committed Information Rate CIRExcess Burst Size Be Addressing Local and Global DLCIsLocal Management Interface LMI Understanding Frame Relay G-3 Network Protocol Addressing and Virtual Interfaces Encapsulation and FragmentationFrame Relay partial mesh support Understanding Frame Relay G-5 User’s Reference Guide Appendix H Event Histories Leased line eventsIsdn events Event Histories Isdn event cause codes Event Histories User’s Reference Guide Event Histories User’s Reference Guide Appendix Isdn Conﬁguration Guide DeﬁnitionsAbout SPIDs Isdn Conﬁguration Guide Example SPIDs Dynamic B-channel usage Other incoming call restrictions User’s Reference Guide Appendix J Binary Conversion Table Binary Conversion Table J-1 Decimal Binary Appendix K Further Reading Further Reading K-1 User’s Reference Guide Further Reading K-3 User’s Reference Guide Technical Speciﬁcations and Safety Information L-1 Appendix L Technical Specifications and Safety InformationPinouts for Auxiliary Port Modem Cable DSR Power requirements Technical Speciﬁcations and Safety Information L-3Description Environment Agency approvals Regulatory noticesNorth America International Technical Speciﬁcations and Safety Information L-5 Australian Safety Information Important safety instructionsDeclaration for Canadian users Telecommunication installation cautions Technical Speciﬁcations and Safety Information L-7Battery User’s Reference Guide Glossary Glossary User’s Reference Guide Glossary User’s Reference Guide Glossary Remapping See network number remapping Glossary User’s Reference Guide Index Index-1 Index-2 Index-3 ISP Index-4 NAT Index-5 Spid Index-6 Limited Warranty and Limitation of Remedies Limited Warranty and Limitation of Remedies User’s Reference Guide