RouteFinder MTASR3 User Guide
MTASR3
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The RIP Route Aging Time text box defines the time interval that must expire before an unused
route entry created by RIP is aged from the route table. The aging timer starts from the addition,
reference, or change of an RIP based routed entry and has a recommended value of 180 seconds.
The Default Route group defines the default route for the RouteFinder. The IP Address field specifies
the full 32-bit IP host address of the next hop for packets being forwarded via default routing. The
router will automatically resolve the IP address to a port number via its IP route table. The Metric
defines the number of hops to the specified IP address and is typically set to a value of 1. If the
default route is for an unnumbered link, select the port from the Port combo box. Finally, whenever
you set up default routing, be sure to disable RIP based routing.
The Static Routes button displays a dialog box that enables you to view, add, edit, or delete static
routes to a target IP address (which can be the address of an IP host, an IP network, or an IP
subnetwork). You must specify the target host IP address and the Gateway Address in dotted decimal
form. The Gateway Address is the IP address of the router that is the next hop toward the target host.
The address mask is the subnet mask of the target IP host, and the Metric is the hop count to the
target host or subnet and can be either 0 or 1.
In most cases, you should not have to change any of the timers (i.e., default TTL, reassembly
timeout, RIP response time and RIP route aging time). The DNS Resolver is supplied for remote
Telnet clients when the router is configured for remote access and the terminal server application is
enabled.
A brief description of OSPF is provided in the following section. For more details on filtering, refer to
the Filtering section of this chapter. For details on other parameters, refer to the online help provided
with your RouteFinder software.
Open Shortest Path First (OSPF)
Open Shortest Path First (OSPF) is a common TCP/IP routing protocol that provides robust and
efficient routing support in the most demanding Internet environments. OSPF calculates routes using
the number of routers, the transmission speed, expected delays, and the cost of the route. Version 2
of the OSPF protocol is designed to be run internal to a single Autonomous System. Each OSPF
router maintains an identical database describing the topology of the Autonomous System. From this
database, a routing table is calculated by constructing a “shortest-path” tree.
OSPF recalculates routes quickly in the event of topological changes, using a minimum of routing
protocol traffic.
Under OSPF, networks can be grouped together into “areas,” each of which is the generalization of
an IP subnetted network. The topology of an area is hidden from the rest of the Autonomous System,
and this information hiding enables a significant reduction in routing traffic. Also, routing within an
area is determined only by the area’s own topology, protecting the area from “bad” routing data.
All OSPF protocol exchanges are authenticated; i.e., only trusted routers can participate in the
Autonomous System’s routing. Furthermore, a variety of authentication schemes can be used; in fact,
separate authentication schemes can be configured for each IP subnet.
Clicking OSPF on the Advanced tab opens the General Setup dialog box.
