IP Setup and Network Address Translation 11-1
Chapter 11
IP Setup and Network Address Translation
The Netopia R3100 uses Internet Protocol (IP) to communicate both locally and with remote networks. This chapter shows you how to configure the router to route IP traffic. You also learn how to configure the router to serve IP addresses to hosts on your local network.
Netopia’s SmartIP features IP address serving and Network Address Translation. For a detailed discussion of Network Address Translation, see Appendix F, “Understanding Netopia NAT Behavior.” This chapter describes how to use the Network Address Translation feature of SmartIP.
Note: When you configured your Netopia R3100 using SmartStart, Network Address Translation was enabled by default. You have the option of disabling it, if you wish. This is done through the System Configuration screens using
This section covers the following topics:
■“Network Address Translation features” on page
■“Using Network Address Translation” on page
■“IP setup” on page
■“IP address serving” on page
Network Address Translation allows communication between the LAN connected to the Netopia R3100 and the Internet using a single IP address, instead of a routed account with separate IP addresses for each computer on the network.
Network Address Translation also provides increased security by hiding the local IP addresses of the LAN connected to the Netopia R3100 from the outside world.
With SmartIP, the setup is simpler, so Internet service providers typically offer
Network Address Translation features
■NAT is selectable on a per connection basis, optionally allowing real addresses to be used for intranet connections and proxied addresses to be used for Internet connections.
■The NAT user can use any combination of proxied and unproxied addresses simultaneously on the available Telco channels. For instance, one unproxied address connection profile can be used to connect to a central office, while another proxied address connection profile can simultaneously connect the user’s Netopia R3100 and LAN to the Internet.
■The single proxy address is acquired at connection time from the answering side. The address can be assigned by the remote router from either a dynamic pool of addresses or a fixed, static address.
■Static NAT (Network Address Translation) Security is made simpler and more reliable by only having to firewall one IP address and by obscuring the internal network structure from the Internet.
