NETGEAR 7000 Series Managed Switch Administration Guide Version 7.2

VLAN Routing OSPF Configuration

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 and/or complex network:

Less network traffic:

Routing table updates are sent only when a change has occurred

Only the part of the table which has changed is sent

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 7000 Series Managed Switch operating as a router and running OSPF will determine 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

CLI Example

This example adds support for OSPF to the configuration created in the base VLAN routing example. The script shows the commands you would use to configure the 7000 Series Managed Switch as an inter-area router. Refer to Figure 7-2.

7-10

IP Routing Services

v1.0, May 2008

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NETGEAR 7000 Series manual Vlan Routing Ospf Configuration