How Packets are Routed

When the NETServer receives a packet, it looks up the packet’s destination in its routing table. If a static route is found, the packet is sent to the gateway listed. If a static route is not found, the NETServer will use a dynamic route. If the routing table contains no routes to the destination, it will send the packet to the Default Gateway. If no such gateway has been defined, the packet is discarded.

Establishing Connections to Remote Gateways

The NETServer can easily forward a packet to a gateway for which there is an established connection, such as a gateway on the same segment of the local LAN or at the other end of an active dial-up connection. All the NETServer has to do in these situations is send the packet out the right port.

However, when there is no existing connection, the NETServer has to do a bit more work. The Location table contains a list of remote gateways that the NETServer can dial into. When the NETServer does not have a connection to a packet’s next hop, it looks up the address of the gateway in the Location table. The Location Table should contain a “dial script” which tells the NETServer how to contact the remote location.

Dial Scripts are most useful for on-demand routing sessions. In these situations, the NETServer connects to a remote gateway only when it has packets queued for that location.

LAN-to-LAN Routing 6-7

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USRobotics NETServer/16, NETServer/8 manual How Packets are Routed, Establishing Connections to Remote Gateways