IP Setup, SmartIP and Network Address Translation 10-5

Internal users can access the Internet as they always do; the external Internet, however, views all traffic from the internal network as originating from 192.163.100.6. Similarly, all traffic your network receives is addressed to 192.163.100.6.

Associating port numbers to nodes

When an IP client, such as a Netscape Navigator or Microsoft Internet Explorer, wants to establish a session with an IP server, such as a Web server, the client machine must know the IP address to use and the TCP service port where the traffic is to be directed.

For example, a Web browser will locate a Web server by using a combination of the IP address and TCP port that the client machine has set up.

Just as an IP address specifies a particular computer on a network, ports are addresses that specify a particular service in a computer. There are many universally agreed-upon ports assigned to various services. For example:

■Web servers typically use port number 80

■All FTP servers use port number 21

■Telnet uses port number 23

■SNMP uses port number 161

To help direct incoming IP traffic to the appropriate server, the Netopia R2121 lets you associate these and other port numbers to distinct IP addresses on your internal LAN using Exported Services. See “IP setup” on page 10-6for details.

Using multiple Connection Profiles

You can enable Network Address Translation on one connection profile, disable it on another, and use the two profiles simultaneously. The profiles might have the following attributes:

■A profile with Network Address Translation disabled connects to your branch or main office. Your company network administrator has assigned you a local IP address range that is consistent with the address space assigned to your company so that you seamlessly integrate when connected. The remote IP address and mask for this profile define only the company’s address space, so that the only IP traffic you send over this connection is for hosts and servers within your company.

■A Network Address Translation profile connects to the Internet via an ISP. Even though the ISP assigns you a dynamic address each time you connect, there will be no address space conflict, since Network Address Translation hides the corporate address you use locally. You enter the ISP’s remote IP address as your default IP gateway so that any IP traffic not intended for your corporate intranet will be directed to the ISP.

Network Address Translation guidelines

Observe the following guidelines when using Network Address Translation.

■The router can export just one local IP address per TCP port, so you can have just one machine available for a given service, such as one FTP server. However, some services, such as Web servers (www-http servers), allow you to change the TCP port on both the server and client. With two different TCP ports

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Netopia R2121 Associating port numbers to nodes, Using multiple Connection Profiles, Network Address Translation guidelines
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R2121 specifications

The Netopia R2121 is a powerful and versatile router designed for both home and office environments, providing seamless connectivity and robust performance for various networking needs. This device offers a range of features and technologies that cater to the demands of modern users seeking reliable internet access, speed, and security.

One of the standout characteristics of the Netopia R2121 is its dual-band technology, which operates on both the 2.4 GHz and 5 GHz frequency bands. This capability allows users to enjoy faster speeds and less interference, as the 5 GHz band is typically less congested than the traditional 2.4 GHz band. With the ability to support multiple devices simultaneously, the R2121 ensures that users can stream videos, play online games, and conduct video conferences without experiencing lag or connectivity issues.

The router is equipped with advanced security features, including WPA3 encryption, which provides enhanced protection against unauthorized access and data breaches. The R2121 also supports a robust firewall system that guards against external threats, ensuring that the user's network remains secure. Additionally, the router includes parental controls, allowing users to manage and restrict internet access for specific devices or set time limits for usage, making it an excellent choice for families.

Another significant advantage of the Netopia R2121 is its extensive coverage area. With high-gain antennas and advanced beamforming technology, the router can deliver strong and stable Wi-Fi signals even in larger homes or office spaces. This technology focuses the Wi-Fi signal directly toward connected devices, minimizing dead zones and improving overall connectivity.

The R2121 also supports both IPv4 and IPv6, ensuring compatibility with current and future internet technologies. This forward-thinking design makes it a future-proof solution for users looking to invest in a reliable router.

In terms of setup and management, the Netopia R2121 features a user-friendly web interface that allows users to easily customize settings, monitor network performance, and manage connected devices. The inclusion of mobile app support further enhances the user experience, enabling remote monitoring and control of the network from anywhere.

Overall, the Netopia R2121 stands out as a robust and reliable router that combines advanced features, enhanced security, and excellent performance, making it an ideal choice for home and business users alike. With its focus on delivering seamless connectivity and comprehensive management options, the R2121 is well-suited for today's connected lifestyles.
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