D-Link DI-206 - Manual (Page 61)

DI-206 ISDN Remote Router
Configuration and Management 49
Dial-Out Network Connections
Dial-out network connections are much different than dial-in
connections.
When a packet on the LAN reaches the router, the DI-206 will:
1. Check its routing table to try to identify where this packet should go. It looks for
two variables in the routing table, Gateway address and Interface. There are four
possible results:
I.
In the case where the destination resides in the same IP network on the LAN,
the routing engine never acts on the packet and it is sent directly to the
destination through the built-in hub.
II. In the case where the destination resides on a different IP network on the LAN
(which can happen when Multiple Home Configuration is set up), the router
will send out an ARP request to obtain the MAC address of the destination
computer (or router) and deliver the packet. Note that defining Static ARPs can
speed up delivery since the router won’t need to send out an ARP request.
III. In the case where the router finds a match in the routing table (which includes
IP Static Routes), it uses the Gateway address and Interface numbers to
identify the correct Remote Network Profile to use to dial out. From the
Remote Network Profile, the router gets the telephone number and other
information and dials out, establishes a connection and delivers the packet. If
you have a connection to the Internet, it is very important that you define the
default next hop router in the IP Static Routes submenu of the console
program as your ISP (see the IP Static Routes section of this manual for more
detailed configuration information). This is because if a user on your LAN
makes a request to download a web page for the first time, for instance, since it
is the first time, the DI-206 will not have any record of the web page’s IP
address. If no default next hop router is defined, the request will be dropped
and the user will get a ‘Destination Unreachable’ error message. However, if a
default next hop router is defined in the IP Static Routes, the DI-206 will pass
this request on to the ISP (the request will go through) and the user will receive
the web page.