CCNA Routing and Switching Portable Command Guide, Third Edition

Chapter 9. Single-Area OSPF

This chapter provides information and commands concerning the following topics:

▪ Configuring OSPF

▪ Using wildcard masks with OSPF areas

▪ Loopback interfaces

▪ Router ID

▪ DR/BDR elections

▪ Modifying cost metrics

▪ Authentication: Simple

▪ Authentication: Using MD5 encryption

▪ Timers

▪ Propagating a default route

▪ Verifying OSPF configuration

▪ Troubleshooting OSPF

▪ Configuration example: Single area OSPF

Configuring OSPF

Using Wildcard Masks with OSPF Areas

When compared to an IP address, a wildcard mask identifies which addresses get matched for placement into an area:

▪ A 0 (zero) in a wildcard mask means ...