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Magnum 12KX Administrator Guide
Chapter 20
RIP
The Routing Information Protocol (RIP) is a routing protocol based on the distance vector algorithm. It is
used for the dynamic creation of the routing table for routers.
When a router is started, the router only knows the networks directly connected to it, and it sends this
routing table to the neighboring routers. At the same time, it requests the routing tables of its neighboring
routers. The router adds this information to its routing table and thus learns which networks can be accessed via which routers, and how much effort is involved in this. In order to detect changes in the network
(when a router fails or starts), the routers regularly repeat the exchange of all the routing tables, usually
every 30 seconds. This involves a considerable bandwidth requirement in large networks.
The costs, also known as the metric, refer to the work involved in reaching a particular network. RIP uses
the hop count for this, which describes the number of routers that are traversed along the path to the
destination network. The name 'distance vector' is derived from the fact that the distance (metric) is the
criterion for determining the route, and the direction is specified by the next hop (vector). The next hop
refers to the neighboring router along the path to the destination address.
An entry in the routing table consists of the address of the next hop, the destination address and the
metric. The RIP routing table always contains the most efficient route to the destination. This is the route
with the smallest metric and the longest suitable network mask prefix.
FIGURE 215 – Counting Hops
Router A
Router B
Router D
Destination Next Hop Metric
Destination Next Hop Metric
Destination Next Hop Metric
SN 10
lokal
0
SN 10
Router A 1
SN 10
Router A 1
SN 11
Router B 2
SN 11
Router C 1
SN 11
Router E 3
Table 39: Routing table to the figure above
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