Example of Subnetting a Class B Address | NETGEAR FWG114P v2

Reference Manual for the ProSafe Wireless 802.11g Firewall/Print Server Model FWG114P v2

Subnet addressing allows us to split one IP network address into smaller multiple physical networks known as subnetworks. Some of the node numbers are used as a subnet number instead. A Class B address gives us 16 bits of node numbers translating to 64,000 nodes. Most organizations do not use 64,000 nodes, so there are free bits that can be reassigned. Subnet addressing makes use of those bits that are free, as shown below.

Class B

Network

Subnet

Node

Figure 11-2: Example of Subnetting a Class B Address

A Class B address can be effectively translated into multiple Class C addresses. For example, the IP address of 172.16.0.0 is assigned, but node addresses are limited to 255 maximum, allowing eight extra bits to use as a subnet address. The IP address of 172.16.97.235 would be interpreted as IP network address 172.16, subnet number 97, and node number 235. In addition to extending the number of addresses available, subnet addressing provides other benefits. Subnet addressing allows a network manager to construct an address scheme for the network by using different subnets for other geographical locations in the network or for other departments in the organization.

Although the preceding example uses the entire third octet for a subnet address, note that you are not restricted to octet boundaries in subnetting. To create more network numbers, you need only shift some bits from the host address to the network address. For instance, to partition a Class C network number (192.68.135.0) into two, you shift one bit from the host address to the network address. The new netmask (or subnet mask) is 255.255.255.128. The first subnet has network number 192.68.135.0 with hosts 192.68.135.1 to 129.68.135.126, and the second subnet has network number 192.68.135.128 with hosts 192.68.135.129 to 192.68.135.254.

Note: The number 192.68.135.127 is not assigned because it is the broadcast address of the first subnet. The number 192.68.135.128 is not assigned because it is the network address of the second subnet.

Networks, Routing, and Firewall Basics

B-5

201-10301-02, May 2005

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NETGEAR FWG114P v2 manual Example of Subnetting a Class B Address

Contents

201-10301-02, May EN 55 022 Declaration of Conformance TrademarksStatement of Conditions FCC Caution Certificate of the Manufacturer/Importer Bestätigung des Herstellers/ImporteursVoluntary Control Council for Interference Vcci Statement 201-10301-02, May Contents Chapter Wireless Configuration Chapter Firewall Protection Content Filtering Chapter Virtual Private Networking Chapter Advanced Configuration Appendix C Preparing Your Network Appendix D Firewall Log Formats Appendix F Virtual Private Networking Glossary Xiv Contents Manual Scope Chapter About This ManualAudience, Scope, Conventions, and Formats Typographical Conventions How to Use This Manual Printing the Full Manual How to Print this ManualPrinting a Page in the Html View Printing a Chapter About This Manual Chapter Introduction Key Features of the FWG114P Flash memory for firmware upgrade NAT off classical routing 802.11g and 802.11b Wireless NetworkingFull Routing on Both the Broadband and Serial Ports Powerful, True Firewall with Content Filtering Wireless Multimedia WMM SupportVirtual Private Networking Autosensing Ethernet Connections with Auto Uplink Security Extensive Protocol Support Netgear Related Products Easy Installation and Management Package Contents LED Descriptions FWG114P v2 Rear Panel Router to a broadband modem Introduction Cabling and Computer Hardware Requirements Connecting the FWG114P v2 to the InternetComputer Network Configuration Requirements What You Will Need Before You Begin Where Do I Get the Internet Configuration Parameters? Internet Configuration Requirements Record Your Internet Connection Information Verify That Basic Requirements Are Met Connecting the FWG114P v2 Wireless Firewall/Print Server Local Port Verify the connections to the firewall It starts automatically LOG in to the Wireless FIREWALL/PRINT Server Login Result RUN the Setup Wizard to Connect to the Internet Be sure to restart your network in the correct sequence Basic Setup Troubleshooting TipsFWG114P v2 Setup Wizard Auto Detection Make sure the network settings of the computer are correct Setup Wizard menu for PPPoE login accounts Wizard-Detected Login Account Setup Connecting the FWG114P v2 to the Internet 10 Setup Wizard menu for Dynamic IP address Wizard-Detected Dynamic IP Account Setup 11 Setup Wizard menu for Fixed IP address Wizard-Detected Fixed IP Account Setup Connect the Firewall to your Isdn or dial-up modem Configure the Serial Port of the Firewall 12 Serial Internet Connection configuration menu Connect to the Internet to test your configuration Testing Your Internet Connection 13 Browser-based configuration Basic Settings menu Manually Configuring Your Internet Connection How to Manually Configure the Primary Internet Connection Connecting the FWG114P v2 to the Internet Observing Performance, Placement, and Range Guidelines Chapter Wireless Configuration FWG114P v2 wireless data security options Implementing Appropriate Wireless Security Wireless Settings menu Understanding Wireless Settings Wireless Access Point Wireless Network. The station name of the FWG114PWireless Card Access List Security Options Feature Default Factory Settings Ssid Netgear Default Factory Settings WEP Encryption Keys Before You Change the Ssid and WEP SettingsAuthentication WPA or WPA2 Radius Settings How to Set Up and Test Basic Wireless Connectivity Wireless Station Access menu How to Restrict Wireless Access by MAC Address To configure WEP data encryption, follow these steps How to Configure WEP Wireless Settings menu WEP Click Wireless Settings in the main menu of the FWG114P How to Configure WPA with Radius Wireless Settings menu WPA with Radius How to Configure WPA2 with Radius Wireless Settings menu WPA2 with Radius How to Configure WPA and WPA2 with Radius Wireless Settings menu WPA and WPA2 with Radius How to Configure WPA-PSK Wireless Settings menu WPA-PSK 10 Wireless Settings menu WPA2-PSK How to Configure WPA2-PSK How to Configure WPA-PSK and WPA2-PSK 11 Wireless Settings menu WPA-PSK and WPA2-PSK Dial-in Chapter Serial Port ConfigurationModem Auto-Rollover Basic Requirements for Serial Port Modem Configuration Configuring a Serial Port ModemHow to Configure a Serial Port Modem How to Configure Auto-Rollover Configuring Auto-RolloverBasic Requirements for Auto-Rollover Auto-Rollover configuration menu Configuring Dial-in on the Serial Port Basic Requirements for Dial-in How to Configure Dial-in How to Configure LAN-to-LAN Connections Configuring LAN-to-LAN SettingsBasic Requirements for LAN-to-LAN Connections LAN-to-LAN configuration menu Serial Port Configuration Firewall Protection and Content Filtering Overview Chapter Firewall Protection Content FilteringUsing the Block Sites Menu to Screen Content Block Sites menu Defining a Service Services and Rules Regulate Inbound and Outbound TrafficThese steps are discussed below Using Inbound/Outbound Rules to Block or Allow Services Rules menu Inbound Rules Port Forwarding Examples of Using Services and Rules to Regulate Traffic Example Port Forwarding to a Local Public Web Server Rule example Videoconference from Restricted Addresses This rule is shown in Figure Service example port forwarding for VPN when NAT is Off Outbound Rules Service Blocking or Port Filtering Rule example Blocking Instant Messenger Other Rules Considerations Rules Menu Options Order of Precedence for Rules Schedule menu Using a Schedule to Block or Allow Content or Traffic Getting E-Mail Notifications of Event Logs and Alerts Setting the Time Zone E-mail menu Firewall Protection and Content Filtering 10 Logs menu Viewing Logs of Web Access or Attempted Web Access Log action buttons are described in Table What to Include in the Event LogLog action buttons Firewall Protection and Content Filtering For Macintosh computers LPR printing Chapter Print ServerPrinting Options FWG114P v2 supports these methods for printing Click Add a printer. Click Next to proceed For Windows XP and 2000, Use TCP/IP LPR PrintingPort Complete the Add Standard TCP/IP Printer Port Wizard Add Printer Wizard Install Printer Software Print Server For Windows 95/98/Me, Use the Netgear Printer Port Driver Set up the Netgear printer port driver Print Server Printing from the Macintosh Windows Printer Port Management Print Port Configuration menu Troubleshooting the Print Server Windows Add Printer Wizard Windows Printer Properties Print Server Print Server Chapter Virtual Private Networking Overview of FWG114P v2 Policy-Based VPN Configuration Using Automatic Key Management Using Policies to Manage VPN Traffic IKE Policy Configuration Menu IKE Policies’ Automatic Key and Authentication Management Field Description General IKE Policy Configuration Fields Field Description Remote VPN Auto Policy Menu VPN Policy Configuration for Auto Key Negotiation VPN Auto Policy fields are defined in the following table VPN Auto Policy Configuration Fields Authenticating Header AH Netbios Enable VPN Policy Configuration for Manual Key Exchange VPN Manual Policy Menu VPN Manual Policy fields are defined in the following table VPN Manual Policy Configuration Fields Value in its Authentication Algorithm Key In field Value in its Encryption Algorithm Key Out field Certificate Revocation List CRL How to Use the VPN Wizard to Configure a VPN Tunnel Walk-Through of Configuration Scenarios on the FWG114P VPN Wizard Start Screen Remote IP Summary screen below displays VPN Wizard Summary 10 VPN Consortium Scenario Vpnc Scenario 1 Gateway to Gateway with Preshared Secrets Scenario 1 FWG114P v2 to FWG114P v2 with Preshared Secrets 11 LAN to LAN VPN access from an FWG114P v2 to an FWG114P 13 LAN IP configuration menu 14 Scenario 1 IKE Policy Set up the IKE Policy illustrated below on the FWG114P Address Set up the FWG114P v2 VPN -Auto Policy illustrated below How to Check VPN Connections 16 VPN Consortium Scenario Vpnc Scenario 2 Gateway-to-Gateway with Certificates Create a certificate request for the FWG114P Install the trusted CA certificate for the Trusted Root CAScenario 2 FWG114P v2 to FWG114P v2 with Certificates Obtain a root certificate FWG114P Highlight, copy and paste this data into a text file 19 Self Certificate Requests table 20 Self Certificates table Set up Certificate Revocation List CRL checking Netgear VPN Client to FWG114P Configuration ProfileSummary 22 Addressing and Subnet Used for Examples Step-By-Step Configuration of FWG114P v2 Gateway 23 Netgear FWG114P v2 IKE Policy Configuration Virtual Private Networking 24 VPN Auto Policy settings Virtual Private Networking Step-By-Step Configuration of the Netgear VPN Client Configure the Connection Network Settings Install the Netgear VPN Client Software on the PC 27 My Identity Configure the Connection Identity Settings Hr5xb84l6aa9r6 Select the Enable Perfect Forward Secrecy PFS check boxClick Pre-Shared Key This example, enter this pre-shared key in this field 31 Connection Security Policy Authentication Phase Configure the Connection Security Policy Check the Encapsulation Protocol ESP check box 32 Connection Security Policy Key Exchange Phase Save the VPN Client Settings Configure the Global Policy Settings From the Client PC to the FWG114P Testing the VPN ConnectionChoose FWG114P From the FWG114P v2 to the Client PC Monitoring the PC VPN Connection 35 Connection Monitor screen Viewing the FWG114P v2 VPN Status and Log Information 36 FWG114P v2 VPN Status screen Viewing Wireless Firewall/Print Server Status Information Chapter Maintenance Status Fields Router Status screen shows the following parameters Dhcp This screen shows the following statistics Click WAN Status to display the WAN connection statusConnection Status Fields Connection Status action buttons Click Show Statistics to display router usage statisticsRouter Statistics Fields WAN Status action buttons are described in Table Viewing a List of Attached Devices Upgrading the Router Software Configuration File Management Settings Backup menu Restoring and Backing Up the Configuration Erasing the Configuration Changing the Administrator Password Maintenance Using the WAN Setup Options Chapter Advanced ConfigurationConnect Automatically, as Required Respond to Ping on Internet WAN Port Setting Up a Default DMZ Server Setting the MTU Size How to Configure Dynamic DNSSetting the WAN Port Speed 10-4 Advanced Configuration Configuring LAN TCP/IP Setup Parameters Using the LAN IP Setup Options 10-6 Advanced Configuration Using Address Reservation Using the Router as a Dhcp server Configuring Static Routes Static Route Entry and Edit Menu Enabling Remote Management Access UPnP Menu Using Universal Plug and Play UPnP Advanced Wireless Settings menu Advanced Wireless Settings Beacon Interval WMM supportRTS Threshold Fragmentation Length 10-14 Advanced Configuration Power LED Not On Chapter TroubleshootingBasic Functioning LAN or Internet Port LEDs Not On LEDs Never Turn Off Troubleshooting the Web Configuration Interface Troubleshooting the ISP Connection If the path is working, you see this message Troubleshooting a TCP/IP Network Using a Ping UtilityTesting the LAN Path to Your Router Click on OK You should see a message like this one If the path is not working, you see this message Testing the Path from Your Computer to a Remote Device Problems with Date and Time Restoring the Default Configuration and Password 11-8 Troubleshooting Protocols Appendix a Technical SpecificationsData and Routing Protocols PPP over Ethernet PPPoE Antenna External detachable 5 dBi omnidirectional WirelessInterface Specifications 10BASE-T or 100BASE-Tx, RJ-45 Appendix B Networks, Routing, and Firewall Basics What is a Router?Related Publications Basic Router Concepts IP Addresses and the Internet Routing Information ProtocolIs normally written as Three Main Address Classes Equals NetmaskSubnet Addressing Combined with Example of Subnetting a Class B Address Netmask Formats Netmask Notation Translation Table for One Octet Private IP Addresses Single IP Address Operation Using NAT Single IP Address Operation Using NAT Related Documents MAC Addresses and Address Resolution ProtocolDomain Name Server Internet Security and Firewalls IP Configuration by Dhcp Stateful Packet Inspection What is a Firewall?Denial of Service Attack Ethernet Cabling Category 5 Cable Quality Table B-1 UTP Ethernet cable wiring, straight-through Figure B-1illustrates straight-through twisted pair cable Inside Twisted Pair Cables Uplink Switches, Crossover Cables, and MDI/MDIX Switching Networks, Routing, and Firewall Basics Networks, Routing, and Firewall Basics Preparing Your Computers for TCP/IP Networking Appendix C Preparing Your Network Install or Verify Windows Networking Components Configuring Windows 95, 98, and Me for TCP/IP Networking Preparing Your Network Selecting Windows’ Internet Access Method Enabling Dhcp to Automatically Configure TCP/IP Settings Installing or Verifying Windows Networking Components Configuring Windows NT, 2000 or XP for IP NetworkingVerifying TCP/IP Properties MacOS 8.6 or Configuring the Macintosh for TCP/IP NetworkingFrom the Apple menu, select Control Panels, then TCP/IP MacOS Verifying TCP/IP Properties for Macintosh Computers What Is Your Configuration Information? Are Login Protocols Used?Verifying the Readiness of Your Internet Account Mail.xxx.yyy.com Preparing Your Network Restarting the Network Outbound Log Appendix D Firewall Log FormatsAction List Field List Other IP Traffic Inbound LogFormat is Operations that the router initiates are logged Format is Router Operation DoS Attack/Scan Other Connections and Traffic to this RouterCommon attacks and scans are logged Datetimepkttype Srcip Dstipaction System Admin Sessions Access Block SiteAll Web Sites and News Groups Visited Date Time Event Direction Service Description Policy Administration LOG Firewall Log Formats This chapter provides an overview of Wireless networking Appendix E Wireless Networking BasicsWireless Networking Overview Infrastructure Mode Ad Hoc Mode Peer-to-Peer Workgroup Authentication and WEP Data EncryptionNetwork Name Extended Service Set Identification Essid Open System Authentication Authentication Figure E-1 Open system authentication Shared Key Authentication Overview of WEP Parameters Figure E-2 Shared key authentication Key Size WEP Configuration Options Wireless Channels WPA Wireless Security How Does WPA Compare to WEP? How Does WPA Compare to Ieee 802.11i? What are the Key Features of WPA Security? Wireless Networking Basics Figure E-3 WPA Overview Login Authentication Figure E-4 802.1x Authentication Sequence Access point replies with an EAP-request identity message WPA Data Encryption Key Management Temporal Key Integrity Protocol Tkip Product Support for WPA Is WPA Perfect? Michael WPA two-phase authenticationNew WPA information element Open system, then 802.1x EAP with Radius or preshared key Changes to Wireless Client Programs Appendix F Virtual Private Networking What is a VPN? IPSec contains the following elements What is IPSec and How Does It Work?IPSec Security Features IPSec Components Encapsulating Security Payload ESP IKE Security Association Authentication Header AH Mode Key Management Understand the Process Before You Begin Interfaces and Addresses VPN Process OverviewVpnc Example Network Interface Addressing WAN Internet/Public and LAN Internal/Private Addressing Setting Up a VPN Tunnel Between GatewaysSubnet Addressing IPSec Security Association IKE VPN Tunnel Negotiation Steps Vpnc IKE Security Parameters Vpnc IKE Phase I Parameters Vpnc IKE Phase II Parameters Testing and TroubleshootingAdditional Reading Virtual Private Networking Table G-1 Summary Configuration Template Log in to Figure G-2 Netgear FVS318 VPN Settings Pre-Configuration Figure G-3 Netgear FVS318 VPN Settings part 1 Main Mode Figure G-4 Netgear FVS318 VPN Settings part 2 Main Mode Figure G-5 Netgear FVS328 IKE Policy Configuration Part Step-By-Step Configuration of FWG114P Gateway B Figure G-6 Netgear FVS328 IKE Policy Configuration Part Figure G-8 Netgear FVS328 VPN Auto Policy part Figure G-9 Netgear FWG114P v2 VPN Auto Policy part Test the VPN Connection Netgear VPN Configuration FVS318 or FVM318 to FWG114P Table H-1 Summary Table H-1 Figure H-2 Dynamic DNS Setup menu Step-By-Step Configuration of FVS318 or FVM318 Gateway a Figure H-3 Netgear FVS318 VPN Settings Pre-Configuration Figure H-4 Netgear FVS318 VPN Settings part 1 Main Mode Figure H-5 Netgear FVS318 VPN Settings part 2 Main Mode Figure H-6 Netgear FVS328 IKE Policy Configuration Part Step-By-Step Configuration of FVS328 Gateway B Figure H-7 Netgear FVS328 IKE Policy Configuration Part Figure H-9 Netgear FVS328 VPN Auto Policy part Figure H-10 Netgear FVS328 VPN Auto Policy part Test the VPN Connection 201-10301-02, May Glossary 802.11e Standard Bandwidth Collision avoidance DNS Domain Name System Encryption Key Gateway IP Internet Protocol address PHY Plug and Play Satellite broadband TCP/IP War Driving Wi-Fi Protected Access and Ieee 802.11i Comparison Wi-Fi Protected Access in Mixed Mode Deployment