Configuring gated
Configuring the OSPF Protocol
You can define various characteristics for an area and interfaces. The following sections describe the configuration statements that you can use in defining an area.
The networks Statement
The networks statement defines the address ranges that forms an OSPF area. This definition applies only to area border routers, where multiple areas are specified, and is required only if you need to compress a number of subnets using a network mask.
A network address followed by a hexadecimal bit mask specifies an IP address range in the network statement. For example, the following address range begins with the network address 193.2.1.16 and includes the first 15 addresses in that network (193.2.1.17 through 193.2.1.31):
193.2.1.16 mask 0xfffffff0
You can specify many separate networks in an address range. Area border routers advertise a single route for each address range.
Figure 3-5 shows an example of a router that is connected to area 0.0.0.1 through the interface 193.2.1.33. The attached network consists of addresses 193.2.1.33 through 193.2.1.47. The other network in the area consists of addresses 193.2.1.17 through 193.2.1.31.
Figure | Network Configuration Example |
Area 0.0.0.1
193.2.1.33 Router A
193.2.1.17 |
|
|
|
|
|
|
| 193.2.1.34 |
|
|
|
|
| ||||
193.2.1.18 |
|
|
|
|
|
|
| |
|
|
|
|
|
|
| ||
|
|
|
|
|
|
| 193.2.1.35 | |
193.2.1.19 |
|
|
|
|
|
|
| |
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
| |
. . . |
|
|
|
|
|
|
| 193.2.1.36 |
|
|
| 193.2.1.31 | Router B | 193.2.1.47 |
| ||
|
|
|
|
| ||||
|
|
|
| . . . | ||||
|
|
|
|
|
|
| ||
|
|
|
|
|
|
| ||
|
|
|
|
|
|
|
|
|
66 | Chapter 3 |