Summary
You have now completed some basic and challenging OSPF scenarios and discovered how powerful OSPF is when enabled on Cisco IOS routers.
OSPF can be configured in single or multiple areas. You saw that all OSPF areas must be connected to the backbone for proper and correct operation. Standard techniques using Cisco IOS show commands were demonstrated to ensure that you have all the required knowledge to monitor and maintain small or large OSPF networks.
Table 3-7 summarizes the commands used in this chapter.
Table 3-7 Summary of IOS Commands used in this Chapter
|
Command |
Purpose |
|
show ip route |
Displays IP routing tables. |
|
router ospf process id |
Enables OSPF routing. The process ID is local to the router. You can have more than one OSPF running. |
|
network mask |
Enables network advertisements out of a particular interface and also the routing of the same interface through OSPF. |
|
show ip ospf |
Displays the OSPF process and details, such as OSPF process ID and router ID. |
|
show ip ospf database |
Displays router's topological database. |
|
show ip ospf neighbor |
Displays OSPF neighbors. |
|
show ip ospf neighbor detail |
Displays OSPF neighbors in detail, providing such parameters as neighbor address, hello interval, and dead interval. |
|
show ip ospf interface |
Displays information on how OSPF has been configured for a given interface. |
|
ip ospf cost |
Interface command that changes the cost of an OSPF interface. |
|
ip ospf priority |
Interface command that changes the DR/BDR election process. |
|
ip ospf network |
Interface command that changes the network type. |
|
interface loopback number |
Creates a loopback interface. |
|
interface Ethernet mod/num |
In configuration mode, enables you modify an interface number, for example interface E0/0. |
|
interface serial mod/num |
In configuration mode, enables you to modify serial interface parameters by module and interface number. For example, interface S0/0. |
|
no ip domain-lookup |
Disables automatic DNS lookup. |
|
ip subnet-zero |
Enables you to use subnet zero on a Cisco router. |
|
show ip protocol |
Displays all routing protocols in use on a Cisco router. |
|
debug ip ospf adj |
Troubleshooting command that displays messages, such as the state of the adjacency, received and sent by a Cisco router from or to neighboring OSPF routers. |
|
hostname name |
Configures a name on a router. |
|
[no] shutdown |
Enables or disables an interface. All hardware interfaces are shut down by default. |