Chapter 19 IP Configuration
NetAtlas Workgroup User’s Guide
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OSPF offers some advantages over traditional vector-space routing protocols (such as RIP).
The following table summarizes some of the major differences between OSPF and RIP.
19.8.1 OSPF Autonomous Systems and Areas
An OSPF autonomous system can be divided into logical areas. Each area represents a group
of adjacent networks. All areas are connected to a backbone (also known as area 0). The
backbone is the transit area to route packets between two areas. A stub area, at the edge of an
AS, is not a transit area since there is only one connection to the stub area.
19.8.2 Interfaces and Virtual Links
An OSPF interface is a link between a layer 3 device and an OSPF network. An interface has
state information, an IP address and subnet mask associated with it. When you configure an
OSPF interface, you first set an interface to transmit OSPF traffic and add the interface to an
area.
You can configure a virtual link to establish/maintain connectivity between a non-backbone
area and the backbone. The virtual ink must be configured on both layer 3 devices in the non-
backbone area and the backbone.
19.8.3 Configuring Basic OSPF Settings
Follow the steps below to activate OSPF and configure basic settings.
1 In the Device Panel list, right-click on a device.
2 Click Configuration > IP Configuration > OSPF.
Table 117 OSPF vs. RIP
OSPF RIP
Network Size Large Small (with up to 15 routers)
Metrics Bandwidth, hop count, throughput, round
trip time and reliability.
Hop count
Convergence Fast Slow
