Fortinet Gate 60D, Administration Manual

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RIP Router Dynamic
FortiGate Version 4.0 Administration Guide
290 01-400-89802-20090424
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How RIP works
When RIP is enabled, the FortiGate unit broadcasts requests for RIP updates from each
of its RIP-enabled interfaces. Neighboring routers respond with information from their
routing tables. The FortiGate unit adds routes from neighbors to its own routing table only
if those routes are not already recorded in the routing table. When a route already exists in
the routing table, the unit compares the advertised route to the recorded route and
chooses the shortest route for the routing table.
RIP uses hop count as the metric for choosing the best route. A hop count of 1 represents
a network that is connected directly to the unit, while a hop count of 16 represents a
network that the FortiGate unit cannot reach. Each network that a packet travels through
to reach its destination usually counts as one hop. When the FortiGate unit compares two
routes to the same destination, it adds the route having the lowest hop count to the routing
table.
Similarly, when RIP is enabled on an interface, the FortiGate unit sends RIP responses to
neighboring routers on a regular basis. The updates provide information about the routes
in the FortiGate routing table, subject to the rules that you specify for advertising those
routes. You can specify how often the FortiGate unit sends updates, how long a route can
be kept in the routing table without being updated, and, for routes that are not updated
regularly, how long the unit advertises the route as unreachable before it is removed from
the routing table.
Viewing and editing basic RIP settings
When you configure RIP settings, you have to specify the networks that are running RIP
and specify any additional settings needed to adjust RIP operation on the FortiGate
interfaces that are connected to the RIP-enabled network.
To view and edit RIP settings go to Router > Dynamic > RIP .
Figure 170 shows the basic RIP settings on a FortiGate unit that has interfaces named
“dmz” and “external”. The names of the interfaces on your FortiGate unit may be different.