Chapter 18. OSPF

Table of Contents

18.1. What is OSPF?
18.2. OSPF Setup
18.2.1. Overview
18.2.2. Standards
18.2.3. Simple example setup
18.2.4. <ospf> config element

18.1. What is OSPF?

OSPF is an interior gatway protocol that allows devices connected together in a network to learn the routes that each other has. It works out the best path across a network of routers and links automatically, and handles failures of links and re-routing traffic another way automatically.

The key feature of OSPF is that it is automatic - it allows you to connect routers up in arbitrary ways, each connected to Ethernet subnets and they find each other and distribute routes. It is very simple to use.

It is also useful for connecting to OSPF aware switches, which can help create a network to which FireBricks are also connected.

Note

OSPF can also be used to create very large networks with multiple areas. Whilst the FireBrick can be a part of such a network, it does not act as an area gateway router. The FireBrick can, however, feed routes from OSPF into BGP routing and so act as an AS-Border gateway router.