NETGEAR 7000 Series Managed Switch - Manual (Page 60)

NETGEAR 7000 Series Managed Switch Administration Guide Version 7.2
7-10 IP Routing Services
v1.0, May 2008
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 .