Reference Manual for the Model CG814M Wireless Cable Modem Gateway NETGEAR, Inc.
© 2002 by NETGEAR, Inc. All rights reserved. Trademarks NETGEAR is a trademark of Netgear, Inc. Microsoft, Windows, and Windows NT are registered trademarks of Microsoft Corporation. Other brand and product names are registered trademarks or trademarks of their respective holders. Statement of Conditions In the interest of improving internal design, operational function, and/or reliability, NETGEAR reserves the right to make changes to the products described in this document without notice.
Bestätigung des Herstellers/Importeurs Es wird hiermit bestätigt, daß das CG814M Wireless Cable Modem Gateway gemäß der im BMPT-AmtsblVfg 243/1991 und Vfg 46/1992 aufgeführten Bestimmungen entstört ist. Das vorschriftsmäßige Betreiben einiger Geräte (z.B. Testsender) kann jedoch gewissen Beschränkungen unterliegen. Lesen Sie dazu bitte die Anmerkungen in der Betriebsanleitung.
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Contents About This Manual ................................................................................................................ xi Audience ........................................................................................................................... xi Typographical Conventions .............................................................................................. xi Special Message Formats ....................................................................................
Connecting the CG814M Gateway .................................................................................2-5 Connecting to Your Computer ..................................................................................2-5 Ethernet .............................................................................................................2-6 USB ...................................................................................................................2-6 Wireless .............................
Viewing Gateway Status ..........................................................................................5-2 Connection Status ....................................................................................................5-4 Current System Time .........................................................................................5-5 Configuring LAN IP Settings ...........................................................................................5-5 LAN IP Setup ........................
Single IP Address Operation Using NAT ................................................................. B-8 MAC Addresses and Address Resolution Protocol ................................................. B-9 Related Documents ................................................................................................. B-9 Domain Name Server ............................................................................................ B-10 IP Configuration by DHCP ..........................................
What Is Your Configuration Information? ................................................................ C-9 Obtaining ISP Configuration Information for Windows Computers ................. C-10 Obtaining ISP Configuration Information for Macintosh Computers ............... C-11 Restarting the Network ................................................................................................ C-12 Glossary....................................................................................................
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Reference Manual for the Model CG814M Wireless Cable Modem Gateway About This Manual Thank your for purchasing the NETGEAR™ CG814M Wireless Cable Modem Gateway. This manual describes the features of the gateway and provides installation and configuration instructions. Audience This reference manual assumes that the reader has intermediate to advanced computer and Internet skills. However, basic computer network, Internet, firewall, and VPN technologies tutorial information is provided in the Appendices.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Special Message Formats This guide uses the following formats to highlight special messages: Note: This format is used to highlight information of importance or special interest. Warning: This format is used to highlight information about the possibility of injury or equipment damage. Danger: This format is used to alert you that there is the potential for incurring an electrical shock if you mishandle the equipment.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 1 Introduction This chapter describes the features of the NETGEAR CG814M Wireless Cable Modem Gateway. About the CG814M Gateway The NETGEAR CG814M Wireless Cable Modem Gateway connects directly to the wide area network (WAN) using its built-in cable modem. It has multiple options to connect to your local area network (LAN), including a 4-port 10/100 Mbps Ethernet switch, a USB port and an 802.11b wireless Access Point.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway A Powerful, True Firewall Unlike simple Internet sharing NAT routers, the CG814M Gateway is a true firewall, using stateful packet inspection to defend against hacker attacks. Its firewall features include: • Denial of Service (DoS) protection Automatically detects and thwarts Denial of Service (DoS) attacks such as Ping of Death, SYN Flood, LAND Attack and IP Spoofing.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Configurable Auto Uplink™ Ethernet Connection With its internal 4-port 10/100 switch, the CG814M Gateway can connect to either a 10 Mbps standard Ethernet network or a 100 Mbps Fast Ethernet network. Both the local LAN and the Internet WAN interfaces are autosensing and capable of full-duplex or half-duplex operation. The gateway incorporates Auto UplinkTM technology.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Easy Installation and Management You can install, configure, and operate the CG814M Gateway within minutes after connecting it to the network. The following features simplify installation and management tasks: • Browser-based management Browser-based configuration allows you to easily configure your gateway from almost any type of personal computer, such as Windows, Macintosh, or Linux.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway What’s in the Box? The product package should contain the following items: • • • • • CG814M Wireless Cable Modem Gateway AC power adapter Category 5 (CAT5) Ethernet cable USB cable Resource CD, including: — This manual — Application Notes, Tools, and other helpful information • • Warranty and registration card Support information card If any of the parts are incorrect, missing, or damaged, contact your NETGEAR dealer.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway You can use some of the LEDs to verify connections. Table 1-1 lists and describes each LED on the front panel of the CG814M Gateway. These LEDs are green when lit. Table 1-1. LED Descriptions Label Activity Description Power On Off Power is supplied to the gateway. Power is not supplied to the gateway. Test On Off A system failure has occurred. Reboot the gateway. Normal operation.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The Gateway’s Rear Panel The rear panel of the CG814M Gateway (Figure 1-2) contains the connections identified below. Figure 1-2: CG814M Gateway Rear Panel Viewed from left to right, the rear panel contains the following elements: • AC power adapter input • 802.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 1-8 Introduction
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 2 Connecting the Gateway to the Internet This chapter describes how to set up the CG814M Gateway on your Local Area Network (LAN), connect to the Internet and perform basic configuration. What You Will Need Before You Begin You need to prepare these three things before you can connect your gateway to the Internet: 1. A computer properly connected to the gateway as explained below. 2.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway LAN Configuration Requirements For the initial connection to the Internet and configuration of your gateway, you will need to connect a computer to the gateway which is set to automatically get its TCP/IP configuration from the gateway via DHCP. Note: Please refer to Appendix C, "Preparing Your Network" for assistance with DHCP configuration.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • You may also refer to the CG814W Resource CD for the NETGEAR Router ISP Guide which provides Internet connection infromation for many ISPs. Once you locate your Internet configuration parameters, you may want to record them on the page below.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Record Your Internet Connection Information 1. Print this page. Fill in the configuration parameters from your Internet Service Provider (ISP). Fixed or Static IP Address: If you have a static IP address, record the following information. For example, 169.254.141.148 could be a valid IP address. Fixed or Static Internet IP Address: ______ . ______ . ______ . ______ Subnet Mask: ______ . ______ . ______ .
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Connecting the CG814M Gateway Before using your modem, you need to do the following: • • • Connect to your computer, using either Ethernet, USB or wireless (see page 2-6). Connect the line from your cable service provider to the cable port of the gateway (see page 2-7). Connect the power adapter (see page 2-8). A typical installation is shown in Figure 2-1, below Figure 2-1: Typical installation using Ethernet.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Ethernet To connect your computer to the modem via Ethernet: 1. Locate the Category 5 Ethernet cable which came with your modem. 2. Connect your computer to the modem using the Ethernet cable.: Note: Note: The CG814M Gateway incorporates Auto UplinkTM technology. Each LOCAL Ethernet port will automatically sense whether the cable plugged into the port should have a 'normal' connection (e.g.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The found new hardware Windows installation wizard will prompt you for the drivers. Browse to the CD and install the USB driver by clicking through the Windows wizard prompts. Wireless Detailed instructions on configuring your wireless devices for TCP/IP networking are provided in the next chapter.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Connecting the Power Adapter To connect the power adapter to the gateway: 1. Plug the connector of the power adapter into outlet on the rear panel of the modem. 2. Plug the other end of the adapter into an AC power outlet. 3. Verify that the PWR LED on the modem is lit. After applying power to the gateway, complete the following steps to verify that power is correctly applied: 1.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Now that the gateway, and the computer are turned on, verify the following: 3. • When power on the gateway was first turned on, the PWR light went on, the numbered LAN LEDs turned on for a few seconds. • The gateway’s LOCAL LINK/ACT lights are lit for any computers that are connected to it. • The gateway’s Cable Link LED is lit, indicating a link has been established to the cable service provider.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway For security reasons, the gateway has its own user name and password. When prompted, enter admin for the gateway User Name and password for the gateway Password, both in lower case letters.. Note: The user name and password are not the same as any user name or password you may use to log in to your Internet connection. 4. Connect to the Internet Figure 2-4: Connection page.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Connecting the CG814M Gateway to the Internet The gateway is now properly attached to your network. You are ready to configure your gateway to connect to the Internet. To continue installation, click on the Basic Settings menu, shown in Figure 2-5..
Reference Manual for the Model CG814M Wireless Cable Modem Gateway If you have set your configuration for Dynamic IP, below, then an IP address shown here is an indication that you have successfully received an IP address from your service provider. If you have set your configuration to Static IP, below, then the IP address you entered will be shown here. For Dynamic IP, the Duration and time of Expiration of the IP address are shown. The IP address is renewed automatically using DHCP. 2.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 5. Firewall Protection: Normally firewall protection should be enabled to protect your network from attacks from the internet. Removing the check from the “Firewall Protection” box disables your firewall. 6. Click Apply to save your settings.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 2-14 Connecting the Gateway to the Internet
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 3 Wireless Configuration This chapter describes how to configure the wireless features of your CG814M Wireless Cable Modem Gateway. Note: If you are configuring the gateway from a wireless PC and you change the gateway’s SSID, channel, or WEP settings, you will lose your wireless connection when you click on Apply. You must then change the wireless settings of your PC to match the gateway’s new settings.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Placement and Range The operating distance or range of your wireless connection can vary significantly based on the physical placement of the wireless gateway. For best results, place your gateway: • • • • near the center of the area in which your PCs will operate, in an elevated location such as a high shelf, away from potential sources of interference, such as PCs, microwaves, and cordless phones, away from large metal surfaces.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Wireless Settings In the Wireless Settings section are the following parameters: • • Name (SSID) Enter a Service Set ID (SSID) value of up to 32 alphanumeric characters. The same SSID must be assigned to all wireless devices in your network. The default SSID is Wireless, but NETGEAR strongly recommends that you change your network’s SSID to a different value. Channel This field determines which operating frequency will be used.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The Wireless Access window displays a list of MAC addresses that will be allowed to connect to the gateway. These PCs must also have the correct SSID and WEP settings. To restrict access based on MAC addresses: 1. Click the Add button to go to the Add/Edit menu. For your convenience, this menu displays a list of currently active wireless cards and their MAC addresses. 2.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • • Automatic - Enter a word or group of printable characters in the Passphrase box and click the Generate button. The four key boxes will be automatically populated with key values. Manual - Enter ten hexadecimal digits (any combination of 0-9, a-f, or A-F) Select which of the four keys will be active. Be sure to click Apply to save your settings in this menu.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 3-6 Wireless Configuration
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 4 Protecting Your Network This chapter describes how to use the firewall features of the CG814M Wireless Cable Modem Gateway to protect your network. Protecting Access to Your CG814M Gateway For security reasons, the gateway has its own user name and password. Also, after a period of inactivity for a set length of time, the administrator login will automatically disconnect.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 2. From the Main Menu of the browser interface, under the Maintenance heading, select Set Password to bring up the menu shown in Figure 4-2. Figure 4-2: Set Password menu 3. To change the password, first enter the old password, and then enter the new password twice. 4. If you would like to reset your gateway to its factory default settings select Yes for Restore Factory Defaults.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • Allowing access to only web sites that you specify as allowed. • Filtering of Proxy servers, Cookies, Java, ActiveX and Popup Windows The section below explains how to configure your gateway to perform these functions. Block Keywords and Domains The CG814M Gateway allows you to restrict access to Internet content based on functions such as web address keywords and web domains. A domain name is the name of a particular web site.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 1. Click on the Block Sites link of the Content Filtering menu. Figure 4-3: Block Sites menu 2. 4-4 To enable keyword blocking or Domain Blocking, check the appropriate Enable box.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 3. Enter Keywords into the Keyword List by typing then in the Add Keyword box, then, click Add Keyword. Some examples of Keyword applications follow: • If the keyword “XXX” is specified, the URL is blocked. • If the keyword “.com” is specified, only websites with other domain suffixes (such as .edu or .gov) can be viewed. • Enter the keyword “.” to block all Internet browsing access.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Most web surfing is done on port 80. The parental control feature monitors port 80 so proxy based web surfing would not be inspected by the parental controls. The proxy filter should be used if parental controls are being used. Cookies A cookie is a text file saved by your web browser which is sent to a particular web servier every time you visit the site. Cookies are used to identify you to the web server automatically.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway rule you have defined. To configure outbound rules on the CG814M Gateway, click the Port Blocking link on the Advanced section of the main menu. Figure 4-4: Port Blocking menu • To block outbound traffic, select the service you would like to block from the drop-down list of predefined services. Click Add. • If the service you would like to block is not in the predefined list, you can add a custom service.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway only one IP address to the Internet, and outside users cannot directly address any of your local computers. However, by defining an inbound rule you can make a local server (for example, a web server or game server) visible and available to the Internet. The rule tells the gateway to direct inbound traffic for a particular service to one local server based on the destination port number. This is also known as Port Forwarding.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 1. Select the service you would like to forward from the drop-down list of predefined services. If the service you would like to forward is not in the predefined list, you can add a custom service. Enter the range of ports you would like to forward and select whether the ports are TCP, UDP or Both. 2. Enter the IP address of the computer on your network to which you would like to direct the inbound traffic • 3. Click Add. 4.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway changed. Port Triggering monitors outbound traffic. When the gateway detects traffic on the specified outbound port, it remembers the IP address of the computer that sent the data and “triggers” the incoming port. Incoming traffic on the triggered port is then forwarded to the triggering computer. An example of Port Triggering for Internet Relay Chat (IRC) is shown in Figure 4-6.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 1. In the Trigger Range, enter the outbound ports that will be monitored for activity. This will be the “trigger”. 2. In the Targe Range, enter the inbound ports that should be forwarded when the trigger occurs. 3. Select the appropriate protocol: TCP, UDP or Both. 4. Check the Enable box 5.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway WAN Port’ check box. This should only be used as a diagnostic tool, since it allows your gateway to be discovered. Don't check this box unless you have a specific reason to do so.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 5 Managing Your Network This chapter describes how to perform network management tasks with your CG814M Wireless Cable Modem Gateway. Network Status Information The CG814M provides a variety of status and usage information which is discussed below.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Viewing Gateway Status From the Main Menu, under Maintenance, select Gateway Status to view the screen in Figure 5-1. Figure 5-1: Gateway Status screen This screen shows the following parameters: Table 5-1. Menu 3.2 - Router Status Fields Field Description Information Standard Specification Compliant The specification to which the gateway’s cable interface is compatible. Hardware Version The hardware version of the gateway.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Table 5-1. Menu 3.2 - Router Status Fields Field CM Certificate Description If the Cable Modem certificate is Installed, it is possible for the service provider to upgrade your Data Over Cable service securely. Status System Up Time This is the time since the gateway has registered with your cable service provider. Network Access This field will change to Allowed when the registration with your cable service provider is complete.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Connection Status From the Main Menu, under Maintenance, select Connection to view the screen in Figure 5-2. Figure 5-2: Connection screen This screen shows detailed information about the status of the connection to your cable service provider that can be used for troubleshooting. The gateway goes through the following steps to be provisioned 1. Acquire and lock Downstream Channel 2. Acquire upstream parameters and range. 3.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Current System Time The date and time is acquired from your cable service provider as part of the registration procedure. Configuring LAN IP Settings The LAN IP Setup menu allows configuration of LAN IP services such as the IP address of the gateway and DHCP. These features can be found under the Advanced heading in the Main Menu in the LAN IP menu.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway DHCP By default, the gateway will function as a DHCP (Dynamic Host Configuration Protocol) server, allowing it to assign IP, DNS server, and default gateway addresses to all computers connected to the router's LAN. The assigned default gateway address is the LAN address of the gateway. IP addresses will be assigned to the attached PCs from a pool of addresses specified in this menu.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Viewing and Emailing Logged Information The gateway will log security-related events such as denied incoming service requests, hacker probes, and administrator logins. If you enabled content filtering, the Logs page shows you when someone on your network tried to access a blocked site. You can enable e-mail notification to receive these logs in an e-mail message. An example is shown below.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Enabling Logs Event E-mail Notification In order to receive logs and alerts by e-mail, you must provide your e-mail information in the E-Mail section of the Logs menu: • In the Contact Email Address, type the e-mail address to which the logs will be sent. Use a full e-mail address (for example, ChrisXY@myISP.com). • In the SMTP Server Name box, type the outgoing SMTP mail server of your ISP (for example, mail.myISP.com).
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Running Diagnostic Utilities The CG814M Gateway has a diagnostics feature. You can use the diagnostics menu to test connectivity to PC using the Ping command: From the Main Menu of the browser interface, under the Maintenance heading, select the Diagnostics menu, shown in Figure 5-5. Figure 5-5: Diagnostics menu To perform a Ping test 1. In the Ping Target section, enter the IP address of the PC you would like to ping. 2.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 5-10 Managing Your Network
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Chapter 6 Troubleshooting This chapter gives information about troubleshooting your CG814M Wireless Cable Modem Gateway. For the common problems listed, go to the section indicated. • Is the gateway on? • Have I connected the gateway correctly? Go to “Basic Functions“ on page 6-1. • I can’t access the gateway’s configuration with my browser. Go to “Troubleshooting the Web Configuration Interface“ on page 6-3.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway e. The Internet Link port LED is lit. If any of these conditions does not occur, refer to the appropriate following section. Power LED Not On If the Power and other LEDs are off when your gateway is turned on: • Make sure that the power cord is properly connected to your gateway and that the power supply adapter is properly connected to a functioning power outlet.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Cable Link LED Not On If the Cable Link LED does not light when connected to your cable television cable, check the following: • Make sure that the coaxial cable connections are secure at the gateway and at the wall jack. • Make sure that your cable internet service has been provisioned by yor cable service provider. Your provider should verify that the signal quality is good enough for cable modem service.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • Make sure you are using the correct login information. The factory default login name is admin and the password is password. Make sure that CAPS LOCK is off when entering this information. If the gateway does not save changes you have made in the Web Configuration Interface, check the following: • When entering configuration settings, be sure to click the APPLY button before moving to another menu or tab, or your changes are lost.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway ping 192.168.0.1 3. Click on OK. You should see a message like this one: Pinging with 32 bytes of data If the path is working, you see this message: Reply from < IP address >: bytes=32 time=NN ms TTL=xxx If the path is not working, you see this message: Request timed out If the path is not functioning correctly, you could have one of the following problems: • Wrong physical connections — Make sure the LAN port LED is on.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway — Check that your PC has the IP address of your gateway listed as the default gateway. If the IP configuration of your PC is assigned by DHCP, this information will not be visible in your PC’s Network Control Panel. Verify that the IP address of the gateway is listed as the default gateway as described in “Verifying TCP/IP Properties“ on page C-6.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Appendix A Technical Specifications This appendix provides technical specifications for the CG814M Wireless Cable Modem Gateway. Network Protocol and Standards Compatibility Data and Routing Protocols: TCP/IP DHCP server and client DNS relay NAT (many-to-one) TFTP client VPN pass through (IPSec, L2TP) Power Adapter North America (input): 120V, 60 Hz, input All regions (output): 12 V DC @ 1.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Local: 10BASE-T or 100BASE-Tx, RJ-45 USB 1.1 Function 802.11b Wireless Access Point Internet: DOCSIS 1.0, upgradeable to DOCSIS 1.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Appendix B Networks, Routing, and Firewall Basics This chapter provides an overview of IP networks, routing, and firewalls. Related Publications As you read this document, you may be directed to various RFC documents for further information. An RFC is a Request For Comment (RFC) published by the Internet Engineering Task Force (IETF), an open organization that defines the architecture and operation of the Internet.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway What is a Router? A router is a device that forwards traffic between networks based on network layer information in the data and on routing tables maintained by the router. In these routing tables, a router builds up a logical picture of the overall network by gathering and exchanging information with other routers in the network. Using this information, the router chooses the best path for forwarding network traffic.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The latter version is easier to remember and easier to enter into your computer. In addition, the 32 bits of the address are subdivided into two parts. The first part of the address identifies the network, and the second part identifies the host node or station on the network. The dividing point may vary depending on the address range and the application. There are five standard classes of IP addresses.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • Class C Class C addresses can have 254 hosts on a network. Class C addresses use 24 bits for the network address and eight bits for the node. They are in this range: 192.0.1.x to 223.255.254.x. • Class D Class D addresses are used for multicasts (messages sent to many hosts). Class D addresses are in this range: 224.0.0.0 to 239.255.255.255. • Class E Class E addresses are for experimental use.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway As a shorter alternative to dotted-decimal notation, the netmask may also be expressed in terms of the number of ones from the left. This number is appended to the IP address, following a backward slash (/), as “/n.” In the example, the address could be written as 192.168.170.237/24, indicating that the netmask is 24 ones followed by 8 zeros.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 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.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Table 6-2. Netmask Formats 255.255.255.0 /24 255.255.255.128 /25 255.255.255.192 /26 255.255.255.224 /27 255.255.255.240 /28 255.255.255.248 /29 255.255.255.252 /30 255.255.255.254 /31 255.255.255.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Single IP Address Operation Using NAT In the past, if multiple PCs on a LAN needed to access the Internet simultaneously, you had to obtain a range of IP addresses from the ISP. This type of Internet account is more costly than a single-address account typically used by a single user with a modem, rather than a router. The CG814M Gateway employs an address-sharing method called Network Address Translation (NAT).
Reference Manual for the Model CG814M Wireless Cable Modem Gateway This scheme offers the additional benefit of firewall-like protection because the internal LAN addresses are not available to the Internet through the translated connection. All incoming inquiries are filtered out by the router. This filtering can prevent intruders from probing your system. However, using port forwarding, you can allow one PC (for example, a Web server) on your local network to be accessible to outside users.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Domain Name Server Many of the resources on the Internet can be addressed by simple descriptive names such as www.NETGEAR.com. This addressing is very helpful at the application level, but the descriptive name must be translated to an IP address in order for a user to actually contact the resource.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway What is a Firewall? A firewall is a device that protects one network from another, while allowing communication between the two. A firewall incorporates the functions of the NAT router, while adding features for dealing with a hacker intrusion or attack. Several known types of intrusion or attack can be recognized when they occur.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Wireless Networking The CG814M Gateway conforms to the Institute of Electrical and Electronics Engineers (IEEE) 802.11b standard for wireless LANs (WLANs). On an 802.11b wireless link, data is encoded using direct-sequence spread-spectrum (DSSS) technology and is transmitted in the unlicensed radio spectrum at 2.5GHz. The maximum data rate for the wireless link is 11 Mbps, but it will automatically back down from 11 Mbps to 5.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway In the infrastructure mode, the wireless access point converts airwave data into wired Ethernet data, acting as a bridge between the wired LAN and wireless clients. Connecting multiple Access Points via a wired Ethernet backbone can further extend the wireless network coverage. As a mobile computing device moves out of the range of one access point, it moves into the range of another.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The 128-bit WEP data encryption method consists of 104 user-configurable bits. Similar to the forty-bit WEP data encryption method, the remaining 24 bits are factory set and not user configurable. Some vendors allow passphrases to be entered instead of the cryptic hexadecimal characters to ease encryption key entry. Wireless Channel Selection IEEE 802.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Note: The available channels supported by the wireless products in various countries are different. The preferred channel separation between the channels in neighboring wireless networks is 25 MHz (5 channels). This means that you can apply up to three different channels within your wireless network. There are only 11 usable wireless channels in the United States.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway are exchanged at one of the two cable connectors. Crossover cables are often unmarked as such, and must be identified by comparing the two connectors. Since the cable connectors are clear plastic, it is easy to place them side by side and view the order of the wire colors on each. On a straight-through cable, the color order will be the same on both connectors.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Appendix C Preparing Your Network This appendix describes how to prepare your network to connect to the Internet through the CG814M Wireless Cable Modem Gateway and how to verify the readiness of broadband Internet service from an Internet service provider (ISP).
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • All versions of UNIX or Linux include TCP/IP components. Follow the instructions provided with your operating system or networking software to install TCP/IP on your computer. In your IP network, each PC and the gateway must be assigned a unique IP addresses. Each PC must also have certain other IP configuration information such as a subnet mask (netmask), a domain name server (DNS) address, and a default gateway address.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway You must have an Ethernet adapter, the TCP/IP protocol, and Client for Microsoft Networks. Note: It is not necessary to remove any other network components shown in the Network window in order to install the adapter, TCP/IP, or Client for Microsoft Networks. If you need to install a new adapter, follow these steps: a. Click the Add button. b. Select Adapter, and then click Add. c.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway If you need Client for Microsoft Networks: 3. a. Click the Add button. b. Select Client, and then click Add. c. Select Microsoft. d. Select Client for Microsoft Networks, and then click OK. Restart your PC for the changes to take effect.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 5. Uncheck all boxes in the LAN Internet Configuration screen and click Next. 6. Proceed to the end of the Wizard. Verifying TCP/IP Properties After your PC is configured and has rebooted, you can check the TCP/IP configuration using the utility winipcfg.exe: 1. On the Windows taskbar, click the Start button, and then click Run. 2. Type winipcfg, and then click OK.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 5. Verify that ‘Client for Microsoft Networks’ and ‘Internet Protocol (TCP/IP)’ are present. If not, select Install and add them. 6. Select ‘Internet Protocol (TCP/IP)’, click Properties, and verify that “Obtain an IP address automatically is selected. 7. Click OK and close all Network and Dialup Connections windows. 8. Make sure your PC is connected to the gateway, then reboot your PC.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway The TCP/IP Control Panel opens: 2. From the “Connect via” box, select your Macintosh’s Ethernet interface. 3. From the “Configure” box, select Using DHCP Server. You can leave the DHCP Client ID box empty. 4. Close the TCP/IP Control Panel. 5. Repeat this for each Macintosh on your network. MacOS X 1. From the Apple menu, choose System Preferences, then Network. 2.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Verifying TCP/IP Properties for Macintosh Computers After your Macintosh is configured and has rebooted, you can check the TCP/IP configuration by returning to the TCP/IP Control Panel. From the Apple menu, select Control Panels, then TCP/IP. The panel is updated to show your settings, which should match the values below if you are using the default TCP/IP settings that NETGEAR recommends: • The IP Address is between 192.168.0.2 and 192.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Verifying the Readiness of Your Internet Account For broadband access to the Internet, you need to contract with an Internet service provider (ISP) for a single-user Internet access account using a cable modem. For a single-user Internet account, your ISP supplies TCP/IP configuration information for one computer.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway • An IP address and subnet mask • A gateway IP address, which is the address of the ISP’s router • One or more domain name server (DNS) IP addresses • Host name and domain suffix For example, your account’s full server names may look like this: mail.xxx.yyy.com In this example, the domain suffix is xxx.yyy.com. If any of these items are dynamically supplied by the ISP, your gateway automatically acquires them.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway If an IP address appears under Installed Gateways, write down the address. This is the ISP’s gateway address. Select the address and then click Remove to remove the gateway address. 6. Select the DNS Configuration tab. If any DNS server addresses are shown, write down the addresses. If any information appears in the Host or Domain information box, write it down. Click Disable DNS. 7.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Restarting the Network Once you’ve set up your computers to work with the gateway, you must reset the network for the devices to be able to communicate correctly. Restart any computer that is connected to the firewall. After configuring all of your computers for TCP/IP networking and restarting them, and connecting them to the local network of your CG814M Gateway, you are ready to access and configure the gateway.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway Glossary 10BASE-T IEEE 802.3 specification for 10 Mbps Ethernet over twisted pair wiring. 100BASE-Tx IEEE 802.3 specification for 100 Mbps Ethernet over twisted pair wiring. 802.11b IEEE specification for wireless networking at 11 Mbps using direct-sequence spread-spectrum (DSSS) technology and operating in the unlicensed radio spectrum at 2.5GHz. Denial of Service attack DoS.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 2 Gateway A local device, usually a router, that connects hosts on a local network to other networks. IETF Internet Engineering Task Force. An open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway NAT See Network Address Translation. netmask A number that explains which part of an IP address comprises the network address and which part is the host address on that network. It can be expressed in dotted-decimal notation or as a number appended to the IP address. For example, a 28-bit mask starting from the MSB can be shown as 255.255.255.192 or as /28 appended to the IP address.
Reference Manual for the Model CG814M Wireless Cable Modem Gateway 4 VPN Virtual Private Network. A method for securely transporting data between two private networks by using a public network such as the Internet as a connection. WAN See wide area network. WEP Wired Equivalent Privacy. WEP is a data encryption protocol for 802.11b wireless networks. All wireless nodes and access points on the network are configured with a 64-bit or 128-bit Shared Key for data encryption. wide area network WAN.
