Filtering example #1 | Netopia R5100, R5300, R5200 specs

13-10 User’s Reference Guide

Src. Port: The source port to match. This is the port on the sending host that originated the packet.

D. Port: The destination port to match. This is the port on the receiving host for which the packet is intended.

On?: Displays Yes when the ﬁlter is in effect or No when it is not.

Fwd: Shows whether the ﬁlter forwards (Yes) a packet or discards (No) it when there’s a match.

Filtering example #1

Returning to our ﬁltering rule example from above (see page 13-7), look at how a rule is translated into a ﬁlter. Start with the rule, then ﬁll in the ﬁlter’s attributes:

1.The rule you want to implement as a ﬁlter is:

Block all Telnet attempts that originate from the remote host 199.211.211.17.

2.The host 199.211.211.17 is the source of the Telnet packets you want to block, while the destination address is any IP address. How these IP addresses are masked determines what the ﬁnal match will be, although the mask is not displayed in the table that displays the ﬁlter sets (you set it when you create the ﬁlter). In fact, since the mask for the destination IP address is 0.0.0.0, the address for Dest IP Addr could have been anything. The mask for Source IP Addr must be 255.255.255.255 since an exact match is desired.

■Source IP Addr = 199.211.211.17

■Source IP address mask = 255.255.255.255

■Dest IP Addr = 0.0.0.0

■Destination IP address mask = 0.0.0.0

Note: To learn about IP addresses and masks, see Appendix B, “Understanding IP Addressing.”

3.Using the tables on page 13-8, ﬁnd the destination port and protocol numbers (the local Telnet port):

■Proto = TCP (or 6)

■D. Port = 23

4.The ﬁlter should be enabled and instructed to block the Telnet packets containing the source address shown in step 2:

■On? = Yes

■Fwd = No

This four-step process is how we produced the following ﬁlter from the original rule:

+-#---	Source IP Addr---	Dest IP Addr-----	Proto-Src.Port-D.Port--		On?-Fwd-+
+----------------------------------------------------------------------					+
1	192.211.211.17	0.0.0.0	TCP 0	23	Yes No

+----------------------------------------------------------------------					+

Image 188

Netopia R5100, R5300, R5200 manual Filtering example #1

Contents

Netopia R5000 Series Routers Part Number Contents Setting up your Router with the SmartStart Wizard Part II Advanced Configuration Vi User’s Reference Guide Aurp Viii User’s Reference Guide Part III Appendixes User’s Reference Guide Index Index-1 Limited Warranty and Limitation of Remedies Xii User’s Reference Guide Part I Getting Started User’s Reference Guide Overview Features and capabilitiesChapter Introduction How to use this guide Type of Service Data Rate Speed Datalink Protocol Chapter Setting Up Internet ServicesFinding an Internet service provider Endorsements Deciding on an ISP account Unique requirementsPricing and support Obtaining information from the ISP Local LAN IP address information to obtainWith Network Address Translation Without Network Address Translation User’s Reference Guide Chapter Making the Physical Connections Find a location What you need Connect the router R5100 SerialR5200 DDS and R5300 T1 Serial Line port Identify the connectors Attach the cables Netopia R5000 Series Router status lights Netopia R5000 Series Router LED front panel User’s Reference Guide Chapter Connecting to Your Local Area Network Readying computers on your local network User’s Reference Guide 10Base-T Connecting to an Ethernet networkCrossover Switch Auxiliary port Port Ethernet hub Adding an external modem Connecting to a LocalTalk network User’s Reference Guide Chapter Setting up your Router with the SmartStart Wizard Installed and properly conﬁgured. See Before running SmartStart Setting up your Router with the SmartStart Wizard SmartStart Wizard configuration screens Setup options screen. You can choose either Easy or Easy option Advanced option Conﬁguration 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 Close the TCP/IP control panel and save the settings Setting up your Router with the SmartStart Wizard User’s Reference Guide Chapter Console-Based Management Snmp Simple Network Management Protocol. See Snmp on Connecting through a Telnet sessionFilter sets ﬁrewalls. See Security on Configuring Telnet software Connecting a console cable to your router Navigating through the console screens Mac ANSI, VT-100, or VT-200 Chapter Easy Setup Easy Setup console screensAccessing the Easy Setup console screens Screen differences See Appendix A, Troubleshooting, for more suggestions Screen similar to the following Main Menu appears Serial Line Easy Setup configuration screen Serial Line Easy Setup screen appears T1 Line configuration screen T1 Line Conﬁguration screen appears DDS Line configuration screen DDS Line Conﬁguration screen appears Easy Setup Profile screen Easy Setup Proﬁle screen appears IP Easy Setup Easy Setup Security Configuration Easy Setup User’s Reference Guide Part II Advanced Configuration User’s Reference Guide Configuration Chapter WAN and System ConfigurationWAN configuration Line configuration for a Serial line Line configuration for a DDS line Line configuration for a T1 line WAN and System Conﬁguration Main Menu Easy Setup Line Configuration Configuring Frame RelayEasy Setup Frame Relay screens WAN Configuration Frame Relay screens Setup Line Configuration Frame Relay configuration WAN and System Conﬁguration Frame Relay Dlci configuration Displaying a Frame Relay Dlci configuration table Changing a Frame Relay Dlci configuration WAN and System Conﬁguration Adding a Frame Relay Dlci configuration Dlci Deleting a Frame Relay Dlci configuration ADD Profile NOW Cancel Creating a new Connection Proﬁle IPX Profile Parameters Remote IPX Network Datalink Frame Relay Options Auto-Detect DLCIs PAP Dial IP Address IPX Network-+ Default profile Configuration Default Profile IP parameters default profile screen IPX parameters default profile screen Scheduled connections switched async only Configuration Scheduled Connections Viewing scheduled connections Adding a scheduled connection Set Weekly Schedule Set Once-Only Schedule Modifying a scheduled connection Deleting a scheduled connection Connection accounting screens switched async only Budget Setup screen appears Budget Statistics in Hhhhmm System configuration screens Navigating through the system configuration screens System configuration features Network protocols setup Filter sets firewallsIP address serving Date and time Console configuration Upgrade feature set Snmp Simple Network Management ProtocolSecurity Logging Installing the Syslog client User’s Reference Guide Chapter IP Setup and Network Address Translation Network Address Translation features HOW NAT Works Using Network Address Translation Previous Screen V2 multicast Numbered Unnumbered Associating port numbers with nodes Sdsl WAN1 Advanced IP/IPX router configuration options Connection Profiles ATM Funi IPX Profile Parameters Remote IPX Network Network Address Translation guidelines IP setup IP Setup and Network Address Translation Select Add Export. The Add Exported Service screen appears Select Service. a pop-up menu of services and ports appears IP subnets IP Setup and Network Address Translation Static routes Static Routes screen will appear Viewing static routes Adding a static route Deleting a static route Rules of static route installationModifying a static route Main System Menu Configuration IP Address Serving 176.163.222.10 Dhcp NetBios Options Serve Bootp Clients IP Address Pools User’s Reference Guide Dhcp NetBIOS Options NetBios Type MacIP KIP forwarding setup Select Release BootP Leases and press Return You have ﬁnished your IP setup Chapter IPX Setup IPX featuresIPX definitions Internetwork Packet Exchange IPX Service Advertising Protocol SAP IPX addressSocket Routing Information Protocol RIP IPX spoofing NetBIOSIPX setup screen Default Gateway Address IPX routing tables User’s Reference Guide AppleTalk protocol Chapter AppleTalk SetupAppleTalk networks AT Routing Table MacIP Routers and seeding Installing AppleTalk Upgrade NOW Configuring AppleTalk EtherTalk setup LocalTalk setup Aurp Free Trade Zone Aurp setupViewing Aurp partners Adding an Aurp partner Modifying an Aurp partner Receiving Aurp connections Configuring Aurp OptionsDeleting an Aurp partner Aurp Options Tickle Interval Hhmmss User’s Reference Guide Chapter Monitoring Tools Quick View status overview General status Current status Status lights Statistics & Logs Network Interface General StatisticsPhysical Interface Event histories WAN Event History Routing tables Device Event History IP routing table IPX routing table IPX Sap Bindery table AppleTalk 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 Select T1 Line Statistics / Diagnostics and press Return T1 DiagnosticsT1 Line Statistics and Diagnostics screen T1 Line Statistics / Diagnostics screen appears Monitoring Tools Web-based monitoring Accounting for switched interfaces only Frame Relay Statistics Connection Status Connect/Disconnect Router Budget Configuration Connection Budgets Connection Budget Configuration Budget Statistics Event History pages Device Event History User accounts Chapter SecuritySuggested security measures Protecting the configuration screens Protecting the Security Options screen 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 User’s Reference Guide How individual filters work Filter’s actionsFiltering rule Parts of a filter Port number comparisons 161 Aurp AppleTalk 387Who 513 Other filter attributes Putting the parts togetherInternet Control Message Protocol Transmission Control Protocol Filtering example #1 Disadvantages of filters Design guidelinesFiltering example #2 An approach to using filters Working with IP filters and filter sets Adding a filter set Naming a new filter set Input and output filters-source and destination Netopia Router ADD this Filter NOW Cancel User’s Reference Guide Modifying filters Moving filtersViewing filters Viewing filter sets Deleting filters Sample IP filter set Modifying filter sets TCP Icmp UDP Possible modifications User’s Reference Guide Main Menu System Configuration Filter Sets Firewalls IPX filters Adding a packet filter IPX packet filtersViewing and modifying packet filters IPX packet filter sets Deleting a packet filterViewing and modifying packet filter sets Adding a packet filter set No Match Viewing and modifying SAP filters IPX SAP filtersDeleting a packet filter set Adding a SAP filter Deleting a SAP filter Adding a SAP filter set IPX SAP filter setsViewing and modifying SAP filter sets Deleting a SAP filter set Firewall tutorial General firewall terms Basic IP packet componentsBasic protocol types ACK Bit Yes Firewall Logic Firewall design rulesExample TCP/UDP Ports Binary representation Logical and function Example IP filter set screen Implied rulesEstablished connections Filter basics Example network Example filters Example Example Example Chapter Utilities and Diagnostics Ping Utilities and Diagnostics Time Stop Ping Trace Route Telnet client Factory defaults Disconnect Telnet console session Transferring configuration and firmware files with Tftp Updating firmware Downloading configuration files Uploading configuration files Transferring configuration and firmware files with Xmodem Idle Do you want to send a saved configuration to your Netopia? Restarting the system User’s Reference Guide Part III Appendixes User’s Reference Guide Appendix a Troubleshooting Configuration problems Console connection problems Network problems How to reset the router to factory defaults Power outages How to reach us Technical supportBefore contacting Netopia Environment profile Netopia Bulletin Board Service 1 Online product informationProduct information can be found in the following FAX-Back User’s Reference Guide About IP addressing What is IP?Appendix B Understanding IP Addressing Subnets and subnet masks Example Using subnets on a Class C IP internet Subnet masks Network configuration Customer Site a ISP Network Background Example Working with a Class C subnetDistributing IP addresses Technical note on subnet masking Configuration Netopia R5000 Series Router Dhcp server characteristics255.255.255.192 255.255.255.0 MacIP serving Using address servingManually distributing IP addresses Tips and rules for distributing IP addresses Serve dynamic WAN clients Dhcp example Nested IP subnets Internet 0.0 C.1 WAN 3719 Broadcasts Packet header types User’s Reference Guide Background Network configurationAppendix C Understanding Netopia NAT Behavior User’s Reference Guide Understanding Netopia NAT Behavior C-3 Netopia Router WWW Server ISP Router LAN Exported services Understanding Netopia NAT Behavior C-5 Important 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 No August User’s Reference Guide Appendix F Technical Specifications and Safety Information Pinouts for Auxiliary port modem cableHD-15 DB-25 Pin Ground Not used Pin Not used DCE Ready HD-15 DB-25 Pin Pin Rset EIA-530Pin Not used Tset EIA-530 Pin Not used Power requirements DescriptionEnvironment Software and protocols Agency approvals Regulatory noticesNorth America R5100, R5200, R5300 FCC Class B Technical Speciﬁcations and Safety Information F-5 Declaration for Canadian users Important safety instructionsAustralian Safety Information R5100 Telecommunication installation cautions Battery User’s Reference Guide Glossary User’s Reference Guide Glossary User’s Reference Guide Glossary Remapping See network number remapping Glossary User’s Reference Guide Index Numerics Display Deﬁned Index-3 Account types LocalTalk conﬁguration Index-4 Index-5 Index-6 Limited Warranty and Limitation of Remedies User’s Reference Guide