Netgear M5300-28G-POE+ (GSM7228PSv1h2) - 12-Port Managed Gigabit Switch Ratgeber Für Administratoren

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OSPF 
133
 Managed Switches
Open Shortest Path First Concepts
For larger networks, Open Shortest Path First (OSPF) is generally used in preference to RIP. 
OSPF offers several benefits to the administrator of a large or complex network:
Less network traffic:
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Routing table updates are sent only when a change has occurred.
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Only the part of the table which has changed is sent.
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Updates are sent to a multicast, not a broadcast, address.
Hierarchical management, allowing the network to be subdivided.
The top level of the hierarchy of an OSPF network is known as an autonomous system (AS) 
or routing domain, and is a collection of networks with a common administration and routing 
strategy. The AS is divided into areas: Intra-area routing is used when a source and 
destination address are in the same area, and inter-area routing across an OSPF backbone 
is used when they are not. An inter-area router communicates with border routers in each of 
the areas to which it provides connectivity.
The managed switch operating as a router and running OSPF determines the best route 
using the assigned cost and the type of the OSPF route. The order for choosing a route if 
more than one type of route exists is as follows:
Intra-area.
Inter-area.
External type 1: The route is external to the AS.
External type 2: The route was learned from other protocols such as RIP.
Inter-area Router
The examples in this section show you how to configure the managed switch first as an 
inter-area router and then as a border router. They show two areas, each with its own border 
router connected to one inter-area router.
The following figure shows a network segment with an inter-area router connecting areas 
0.0.0.2 and 0.0.0.3. The sample script shows the commands used to configure the managed 
switch as the inter-area router in the diagram by enabling OSPF on port 1/0/2 in area 0.0.0.2 
and port 1/0/3 in area 0.0.0.3.