Initial Configuration

Configure the Route Table

Routing in a Vipersat Network

CDM-570/570L modem/routers operating in Vipersat mode do not use the small or large network described in the CDM-570/570L Installation and Opera- tion Manual. There is no HDLC address in a Vipersat network; instead, the CDM-570/570L role designation — Hub or Remote, Expansion unit or not — determines routing rules that prevent multicast loops. This simplifies the config- uration of a Vipersat network.

Because satellite networks are often used as extensions for access to services such as the Internet or the PSTN, they lend themselves quite readily to private addressing. For example, to provide Internet access to the satellite network, only the Hub requires a public IP address in order for the entire satellite network that is controlled by the Hub to have access to the Internet backbone. Utilizing Network Address Translation (NAT), the administrator can effectively address the network using a minimum number of static route statements.

Example:

The IP address 172.16.0.0 is the private address network number for class B networks. If there is a router at the Hub with a connection to the Internet, the operator can define the local network as a class B. If the operator splits the Class B in half and points the upper half toward the satellite there will be over 16000 usable addresses at the Hub as well as at the Remotes. For details on IP address- ing, refer to Appendix A, "Network Addressing".

By putting the one route statement “Remotes 172.16.128.0/17 Wan to Sat” in the TDM Hub modem, and by using the route statement “GW 0.0.0.0/0 Wan to Sat” at each of the remote modems, the network will successfully route packets. The remotes can then be sub-netted as class C networks or below. Additional routers at the remotes can be added for unusually large sites, allowing an addi- tional layer of NAT without requiring any more explicit routing within the Vipersat Modem/Routers.

Refer to the CDM-570/570L Installation and Operation Manual for additional information on entering routes.

Creating the Routes

The following procedure outlines the basic route structure that the target CDM-570/570L will require for its role in the network. One of the key routes

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Vipersat CDM-570/570L User Guide

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Cables to Go CDM-570L manual Configure the Route Table, Routing in a Vipersat Network, Creating the Routes